CN101390244A - Liquid material for electrochemical cells - Google Patents

Abstract

The present application discloses the use of liquid precursor materials to prepare processable polymer electrolytes that can be used to form proton exchange membranes for use in electrochemical cells. The application also discloses the use of liquid precursor materials to prepare a processable ink composition that can be conformally applied to proton exchange membranes and electrode materials for electrochemical cells. The present application also discloses the use of a photocured perfluoropolyether (PFPE) to form a micro-flow channel electrochemical cell.

Description

Liquid materials for electrochemical cells

Related Application Cross Reference

This application is based on and claims priority to U.S. Provisional Patent Application No. 60/538,706, filed January 23, 2004, and U.S. Provisional Patent Application No. 60/538,878, filed January 23, 2004, both of which are The content is incorporated herein by reference.

Government interests

This invention was made with US Government support from the Office of Naval Research Grant No. N00014210185 and the National Science Foundation's Center for Science and Technology Project Contract No. CHE-9876674. The US Government has certain rights in this invention.

technical field

The present invention relates to liquid materials for use in electrochemical cells.

List of abbreviations

AC = AC

Ar = Argon gas

℃ = Celsius

cm = centimeter

CSM ＝ cure site monomer

g = gram

h = hours

HMDS ＝ Hexamethyldisilazane

IL = Imprint lithography

MCP ＝ Micro Contact Printing

Me = methyl

MEA = Membrane Electrode Assembly

MEMS ＝ micro-electromechanical system

MeOH = Methanol

MIMIC ＝ capillary micromolding

mL = milliliter

mm = mm

mmol = millimole

M _n = number average molecular weight

m.p. = melting point

mW = milliwatt

NCM ＝ Nano Contact Molding

NIL = nanoimprint lithography

nm = nanometer

Pd = Palladium

PDMS ＝ Polydimethylsiloxane

PEM = Proton Exchange Membrane

PFPE ＝ Perfluoropolyether

PSEPVE= Perfluoro-2-(2-fluorosulfonylethoxy)propyl vinyl ether

PTFE ＝ polytetrafluoroethylene

SAMIM = solvent-assisted micromolding

SEM = scanning electron microscope

Si = silicon

TFE = Tetrafluoroethylene

μm = micron

UV = ultraviolet light

W = Watt

ZDOL = Poly(tetrafluoroethylene oxide-co-difluoroformaldehyde) α,ω diol

Background technique

Fuel cells are safe, environmentally friendly sources of electrical energy for portable equipment, vehicles (including hybrid vehicles), generators, and aerospace and military applications. However, due to cost, size and lack of immediate need to replace current power sources such as batteries and gasoline or diesel powered internal combustion engines, the state of the art fuel cells has not yet had a significant impact on the mainstream market. However, the long-term need to find alternative power sources has become increasingly apparent. For example, gasoline and diesel powered internal combustion engines are environmentally harmful. In contrast, fuel cell by-products are clean and in some cases contain only water.

Furthermore, as portable electronic devices, such as cellular phones, notebook computers, and hand-held personal organizers, are becoming smaller, the need for smaller power sources, such as miniature fuel cells, has become apparent. However, current fuel cell technology typically requires large fuel cell stacks containing costly flat proton exchange membranes (PEMs).

Additionally, consumer products require power sources that can operate for extended periods of time without recharging. Micro fuel cells typically provide longer sustained power output from a single fuel cartridge. For example, chemical fueling for tiny fuel cells can power devices up to 10 times as long as batteries at a time. Also, once the energy gets low, the energy level can be restored simply by replacing the fuel cartridge.

(E.I.duPont de Nemours andCo.，Wilmington，Delaware，美国)获得，或者是类似的可商购材料。通常以膜的最终形式提供这些材料用于随后的使用，例如以具有平面矩形或正方形几何形状的非热塑形式。如果膜是平的且光滑的，即无图案的，催化剂层也必须是平的。此外，这种膜典型地必须具有可处理的至少一定的最小厚度。另外，功率密度或传导率通常与膜厚成比例，即膜越厚，功率密度越低。Most fuel cells use copolymers of tetrafluoroethylene (TFE) and perfluoromonomers containing sulfonic acid groups, such as perfluorosulfonyl fluoride ethoxypropyl vinyl ether (PSEPVE). One of these copolymers can be used as

(EIduPont de Nemours and Co., Wilmington, Delaware, USA), or similar commercially available materials. These materials are usually provided in the final form of a film for subsequent use, for example in a non-thermoplastic form with a planar rectangular or square geometry. If the membrane is flat and smooth, ie unpatterned, the catalyst layer must also be flat. Furthermore, such films typically must have at least a certain minimum thickness to be handleable. Additionally, power density or conductivity is generally proportional to film thickness, ie, the thicker the film, the lower the power density.

In addition, Lu et al ., Electrochimica Acta, 49, 821-828 (2003) have described silicon-based materials for miniature direct methanol fuel cells. Silicon-based miniature direct fuel cells are rigid, fragile devices that are typically expensive and time-consuming to manufacture. Additionally, incorporating actuation valves in silicon-based materials is difficult or impossible due to the rigid nature of the material. Furthermore, the silicon-based micro direct methanol fuel cells described by Lu et al . have an active area to macroscopic area ratio approximately equal to one.

Additionally, good contact between the electrodes, proton exchange membrane (PEM) and catalyst is essential in currently available fuel cell technologies. High power density relies on conformal contact between electrodes, catalysts, and PEM. More research has been devoted to developing new PEMs and new catalysts, but little research has been done on new catalyst ink compositions. Traditional catalyst inks or tapes typically consist of a catalyst such as platinum, an electrode material such as carbon black, and A dispersion of water and alcohol.

Furthermore, currently available PEMs in the art consist of a single equivalent weight (EW), which introduces a trade-off between power density and methanol permeability.

Accordingly, there is a need in the art for improved electrochemical cells, particularly micro fuel cells capable of powering small, portable electronic devices, and for improved electrochemical cell assemblies.

Contents of the invention

The present invention describes liquid materials for use in electrochemical cells, such as fuel cells, chlor-alkali cells, batteries, and the like. Accordingly, in some embodiments, the present invention provides a polymer electrolyte composition and a method of making a polymer electrolyte. In some embodiments, the method comprises: (a) providing a 100% solidified liquid precursor material, wherein the 100% solidified liquid precursor material comprises from about 70% to about 100% by weight of polymeric material; and (b) processing said liquid precursor material to form a polymeric electrolyte.

In some embodiments, the 100% cured liquid precursor material comprises a material selected from the group consisting of proton conducting materials, precursors of proton conducting materials, and combinations thereof. In some embodiments, the 100% cured liquid precursor material comprises a material selected from the group consisting of monomers, oligomers, macromers, ionomers, and combinations thereof. In some embodiments, at least one of the monomers, oligomers, macromers, and ionomers comprises a functionalized perfluoropolyether (PFPE) material.

In some embodiments, the functionalized perfluoropolyether (PFPE) material comprises a backbone structure selected from the following structures:

和

and

wherein X is present or absent, and when X is present, includes a capping group, and n is an integer from 1-100. Accordingly, in some embodiments, the functionalized PFPE material is selected from the group consisting of:

和

and

wherein R is selected from alkyl, substituted alkyl, aryl and substituted aryl, and wherein m and n are each independently an integer of 1-100.

In some embodiments, the ionomer is selected from sulfonic acid materials and phosphoric acid materials. In some embodiments, the sulfonic acid material comprises a derivative of the sulfonic acid material. In some embodiments, derivatives of sulfonic acid materials include materials comprising perfluoro-2-(2-fluorosulfonylethoxy)propyl vinyl ether (PSEPVE) of the general formula:

Wherein q is an integer of 1-5.

In some embodiments, derivatives of sulfonic acid materials include materials selected from the group consisting of:

和

and

in:

Y is selected from _-SO2F and _-SO3H ;

_R is selected from alkyl, substituted alkyl, hydroxyl, alkoxy, fluorine-containing alkenyl, cyano and nitro;

X ₁ is selected from the group consisting of bond, O, S, SO, SO ₂ , CO, NR ₂ and R ₃ ;

X ₂ is selected from O, S and NR ₂ ,

in:

R _is selected from hydrogen, alkyl, substituted alkyl, aryl, and substituted aryl; and

_R is selected from alkylene, substituted alkylene, aryl and substituted aryl;

Ar is selected from aryl and substituted aryl;

B is 1,2-perfluorocyclobutylene;

t is an integer of 1-3;

m is an integer from 0 to 1000;

p is an integer from 1 to 1000; and

q is an integer of 1-5.

Accordingly, in some embodiments, the present invention provides polymer electrolytes comprising 100% cured liquid precursor material, wherein the 100% cured liquid precursor material comprises from about 70% to about 100% by weight polymerizable material.

In some embodiments, the present invention provides a method of making a patterned polymer electrolyte, the method comprising:

(a) contacting a liquid precursor material with a patterned substrate, wherein the patterned substrate has a predetermined geometry and macroscopic surface area; and

(b) processing the liquid precursor material to form a patterned polymer electrolyte.

In some embodiments, the liquid precursor material includes a material selected from the group consisting of proton-conducting materials, precursors of proton-conducting materials, and combinations thereof. In some embodiments, the patterned polymer electrolyte has a surface area greater than the macroscopic surface area of the patterned substrate.

In some embodiments, the present invention provides a method of preparing a polymer electrolyte having multiple equivalent weights, the method comprising:

(a) applying to the substrate a first liquid precursor material having a first equivalent weight;

(b) treating said first liquid precursor material to form a first layer of treated liquid precursor material on the substrate;

(c) applying a second liquid precursor material having a second equivalent weight to the first layer of treated liquid precursor material on the substrate; and

(d) treating the second liquid precursor material to form a polymer electrolyte having a plurality of equivalent weights.

In some embodiments, the method includes repeating steps (c) through (d) with a predetermined plurality of liquid precursor materials having a plurality of equivalent weights to form a polymer electrolyte having a plurality of equivalent weights.

In some embodiments, the first liquid precursor material, the second liquid precursor material, and the plurality of liquid precursor materials are selected from the group consisting of proton-conducting materials, precursors of proton-conducting materials, and combinations thereof. In some embodiments, the first equivalent weight is greater than the second equivalent weight. In some embodiments, the second equivalent weight is greater than the plurality of equivalent weights. Thus, an equivalent weight gradient is provided along the cross-section of the polymer electrolyte.

The present invention also provides a method of forming a membrane electrode assembly (MEA). In some embodiments, the method of forming a membrane electrode assembly (MEA) comprises:

(a) providing a patterned proton exchange membrane;

(b) providing a first catalyst material and a second catalyst material;

(c) providing a first electrode material and a second electrode material;

(d) operatively disposing said proton exchange membrane, said first and second catalyst materials, and said first and second electrode materials in conductive communication to form a membrane electrode assembly.

In some embodiments, at least one of the first catalyst material and the second catalyst material comprises a processable catalyst ink composition. In some embodiments, the processable catalyst ink composition includes a liquid precursor material. In some embodiments, the treatable catalyst ink composition is conformally applied to either or both the proton exchange membrane and the electrode material.

In some embodiments, the method of the present invention for forming a membrane electrode assembly comprises:

(a) providing a first electrode material;

(b) providing a second electrode material;

(c) disposing said first electrode material and second electrode material in a spatial arrangement forming a gap between said first electrode material and second electrode material;

(d) disposing a liquid precursor material in the space between said first electrode material and second electrode material; and

(e) processing the liquid precursor material to form a membrane electrode assembly.

In some embodiments, the liquid precursor material is selected from proton-conducting materials, precursors of proton-conducting materials, and combinations thereof.

The invention also provides methods of forming electrochemical cells. In some embodiments, the method includes:

(a) providing at least one layer of perfluoropolyether (PFPE) material comprising at least one microfluidic channel;

(b) providing a first electrode material and a second electrode material;

(c) providing a first catalyst material and a second catalyst material;

(d) provision of proton exchange membranes; and

(e) operatively disposing said at least one layer of PFPE material, said first electrode material, said second electrode material, said first catalyst material, said second catalyst material, and said proton exchange membrane to form electrochemical cell.

Additionally, in some embodiments, the present invention provides methods of operating electrochemical cells. Thus, the electrochemical cells of the present invention can be used to operate portable electronic devices (such as, but not limited to, portable generators, portable instruments), power tools, electronic devices (such as consumer electronics and military electronics), road or traffic signs, Backup power and personal vehicles (such as cars).

It is therefore an object of the present invention to provide novel liquid materials for use in electrochemical cells. Said and other objects are achieved in whole or in part by the present invention.

The above objects, other aspects and objects of the present invention will become apparent from the following description in conjunction with the accompanying drawings and the description of the preferred embodiment.

Description of drawings

Figures 1A and 1B provide a schematic representation of an embodiment of the process of the present invention for the preparation of proton exchange membranes.

Figure 1A is a schematic illustration of a peg mold that can be interleaved and used as a mold (eg, a patterned substrate) for forming a patterned proton exchange membrane of the present invention.

Figure IB is a schematic illustration of a proton exchange membrane prepared from the interleaved peg mold provided in Figure IA.

2A and 2B are scanning electron micrographs of a proton exchange membrane (PEM) containing a sharkskin pattern prepared by the method of the present invention.

Figure 2A is a scanning electron micrograph of a PEM of the present invention comprising a sharkskin pattern before hydrolysis.

Figure 2B is a scanning electron micrograph of a PEM of the present invention comprising a sharkskin pattern after hydrolysis.

3A and 3B are schematic diagrams of an embodiment of the method of the invention using a patterned electrode pair as a mold to form a proton exchange membrane of the invention.

Figure 4 is a graph showing the conductivity of an embodiment of a proton exchange membrane of the present invention having an equivalent weight of 1900 under fully hydrated conditions.

Figure 5 is a graph showing the conductivity of a proton exchange membrane embodiment of the present invention having an equivalent weight of 1250 under fully hydrated conditions.

Figure 6 is a graph showing the conductivity of an embodiment of a proton exchange membrane of the present invention having an equivalent weight of 850 under fully hydrated conditions.

Figure 7 is a graph showing the conductivity of an embodiment of a proton exchange membrane of the present invention having an equivalent weight of 660 under fully hydrated conditions.

Figure 8 is a graph showing the conductivity of a proton exchange membrane embodiment of the present invention having an equivalent weight of 550 under fully hydrated conditions.

Figures 9A and 9B are schematic diagrams of proton exchange membrane (PEM) embodiments of the present invention comprising liquid materials of varying equivalent weights, which provide an equivalent weight gradient along the cross-section of the PEM.

10A and 10B are schematic diagrams of an embodiment of the method of the present invention for forming a catalyst ink ribbon layer.

Figure 10A is a schematic illustration of an embodiment of the method of the present invention for forming a catalyst ink ribbon layer on a planar electrode material.

Figure 10B is a schematic diagram of an embodiment of the method of the present invention used to form a ribbon layer of catalyst ink on a patterned proton exchange membrane.

11A-11C are schematic illustrations of an embodiment of the present method for coating a patterned proton exchange membrane with a processable catalyst ink composition and electrode material.

11A is a schematic diagram of one embodiment of the method of the present invention in which a patterned PEM is conformally coated with a processable catalyst ink composition, followed by coating with an electrode material, thereby forming a planarized surface of the electrode material.

Figure 1 IB is a schematic diagram of one embodiment of the method of the present invention wherein a patterned PEM is conformally coated with a processable catalyst ink composition followed by conformal coating with an electrode material, thereby forming a conformal surface of the electrode material.

Figure 11C is a schematic diagram of one embodiment of the method of the present invention wherein a patterned PEM is conformally coated with a treatable catalyst ink composition to form a planarized surface of the treatable catalyst ink composition, followed by conformal coating with an electrode material coated to form a planarized surface of the electrode material.

12A and 12B are scanning electron micrographs of an embodiment of a patterned PEM of the present invention conformally coated with a catalyst using an electrospray method.

Figure 13 is a scanning electron micrograph of an embodiment of a patterned PEM of the present invention conformally coated with a catalyst using a vapor deposition method.

14A and 14B are schematic diagrams of embodiments of membrane electrode assemblies of the present invention.

Figure 14A is a schematic illustration of an embodiment of a three-dimensional membrane electrode assembly (MEA) of the present invention with conformal catalyst support made from a three-dimensional proton exchange membrane (PEM).

Figure 14B is a schematic illustration of an embodiment of a two-dimensional electrode of the present invention with non-conformal catalyst support.

Figure 15 is a schematic illustration of an embodiment of a three-dimensional membrane electrode assembly (MEA) of the present invention fabricated from a three-dimensional proton exchange membrane (PEM) and a three-dimensional electrode with conformal catalyst support.

Figure 16 depicts a photolithographic process used to pattern electrode materials such as carbon black.

17A and 17B are schematic diagrams of embodiments of microfluidic fuel cells of the present invention.

Figure 17A is a cross-sectional view of an embodiment of a fuel cell of the present invention.

Figure 17B is a plan view of an embodiment of a fuel cell of the present invention.

18A-18C are a series of schematic end views depicting the process of forming a patterned layer of perfluoropolyether (PFPE) material containing microfluidic channels of the present invention.

Detailed ways

The present invention describes the use of liquid materials in electrochemical cells, such as fuel cells, chlor-alkali cells, batteries. Accordingly, the present invention describes liquid materials for the preparation of polymer electrolytes, such as proton exchange membranes, for electrochemical cells, including proton exchange membranes with an equivalent weight gradient. The present invention also describes improved electrochemical cell technology incorporating patterned membranes and electrodes. In addition, the present invention describes liquid materials for the preparation of membrane electrode assemblies in which enhanced conformal contact between electrochemical cell components is exhibited. Accordingly, the present invention also describes liquid materials for use in the preparation of disposable catalyst ink compositions for electrochemical cells. Additionally, the present invention describes photocurable perfluoropolyethers for use in the fabrication of microfluidic devices used in electrochemical cells such as miniature direct methanol fuel cells and hydrogen fuel cells. The invention also describes methods of operating electrochemical cells.

The present invention will now be described more fully hereinafter with reference to Examples, which represent representative embodiments, and to the accompanying drawings. However, this invention may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this will be thorough and complete to describe the invention, and will fully convey the scope of the embodiments to those skilled in the art.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the subject matter described herein belongs. All publications, patent applications, patents, and other references mentioned herein are hereby incorporated by reference in their entirety.

Throughout the specification and claims, a given formula or name shall encompass all optical and stereoisomers, as well as racemic mixtures of such isomers and mixtures, which may exist.

I. Liquid Precursor Materials

The present invention describes liquid pourable precursor materials that are processable, that is, that can be formed into or conformed to different shapes, and that can be used to make high surface area PEMs. In some embodiments, as noted in more detail herein below, a liquid precursor material can be patterned and processed (such as, but not limited to, curing into a solid) through a patterned substrate (such as a mold) to form a pattern optimized PEM.

As used herein, the term "100% cured liquid precursor material" refers to a liquid polymer precursor material in which substantially all components are polymerized when processed (eg, cured). Thus, in some embodiments, a "100% cured liquid precursor material" is substantially free of unpolymerized material. This property of "100% cured liquid precursor material" distinguishes this material from solutions or dispersions of liquid precursor materials known in the art, wherein the liquid material may contain from about 80% to about 98% by weight of solvents or other unpolymerized materials. For example, one perfluorinated liquid composition commonly used in the art for preparing ion exchange membranes comprises about 2% to about 18% by weight polymeric material and about 82% to about 98% by weight non-polymerizable solvent. See US Patent No. 4,433,082 to Grot, which is hereby incorporated by reference in its entirety.

Thus, in some embodiments, the 100% cured liquid material comprises from about 70% to about 75% by weight polymerizable material. In some embodiments, the 100% cured liquid material comprises from about 75% to about 80% by weight polymerizable material. In some embodiments, the 100% cured liquid material comprises from about 80% to about 85% by weight polymerizable material. In some embodiments, the 100% cured liquid material comprises from about 85% to about 90% by weight polymerizable material. In some embodiments, the 100% cured liquid material comprises from about 90% to about 95% by weight polymerizable material. In some embodiments, the 100% cured liquid material comprises about 95% to about 98% by weight polymerizable material. In some embodiments, the 100% cured liquid material comprises from about 98% to about 100% by weight polymerizable material. Thus, in some embodiments, the 100% cured liquid material comprises from about 70% to about 100% by weight polymerizable material.

Additionally, in some embodiments, the liquid precursor material includes a fluorinated system. In some embodiments, the fluorinated system includes perfluoropolyether (PFPE) materials. In some embodiments, the PFPE material includes vinyl functionalized materials including, but not limited to, vinyl methacrylate.

In some embodiments, the liquid precursor material comprises a proton conductivity enhancing substance, including vinyl ethers such as perfluoro-2-(2-fluorosulfonylethoxy)propyl vinyl ether (PSEPVE). The term "proton-conducting material" as used herein refers to a material within which protons can migrate. For example, in some embodiments, protons migrate from the anode to the cathode through the proton-conducting material. For example, proton conductivity is measured by alternating current (AC) impedance methods well known in the art and is typically given in units of Siemens/centimeter (S/cm). Such proton conducting materials typically have a proton conductivity greater than about 0.01 S/cm.

In some embodiments, the liquid precursor material contains other substances that adjust the physical properties of the material, including modulus, permeability to methanol and other liquids, wettability, tensile strength, toughness, flexibility, and especially thermal nature. Examples of synthetic methods for preparing the liquid precursor materials disclosed herein are found in Examples 1-6.

Accordingly, in some embodiments, the method of preparing a polymer electrolyte comprises:

(a) providing a 100% cured liquid precursor material, wherein the 100% cured liquid precursor material comprises from about 70% to about 100% by weight polymerizable material; and

(b) processing the 100% cured liquid precursor material to form a polymer electrolyte.

In some embodiments, the 100% cured liquid precursor material comprises proton-conducting materials, precursors of proton-conducting materials, and combinations thereof.

In some embodiments, the 100% cured liquid precursor material comprises a material selected from the group consisting of monomers, oligomers, macromers, ionomers, and combinations thereof.

As used herein, the term "monomer" refers to molecules that can undergo polymerization to contribute building blocks, ie, atoms, groups of atoms and/or groups of atoms, to the basic structure of a macromolecule or polymer. The term "oligomer" refers to a relatively intermediate molecular weight molecule whose structure contains a small number of building blocks derived from molecules of lower relative molecular weight. The term "macromolecule" refers to a macromolecule or polymer comprising reactive end groups that enable the macromolecule to function as a monomer and allow monomer units to contribute to the final macromolecule or polymer chain. The term "ionomer" refers to a macromolecule in which multiple building blocks contain ionizable groups, ionic groups, and combinations thereof.

In some embodiments, at least one of the monomers, oligomers, macromers, and ionomers comprises a functionalized perfluoropolyether (PFPE) material. In some embodiments, the functionalized perfluoropolyether (PFPE) material comprises a backbone structure selected from the following structures:

and

wherein X is present or absent, and when X is present, includes a capping group, and n is an integer from 1-100.

In some embodiments, the functionalized PFPE material is selected from the following materials:

和

and

wherein R is selected from the group consisting of alkyl, substituted alkyl, aryl, and substituted aryl; and wherein m and n are each independently an integer from 1 to 100.

In some embodiments, the functionalized PFPE material has the following structure:

In some embodiments, the ionomer is selected from sulfonic acid materials and phosphoric acid materials. In some embodiments, the ionomer comprises sulfonic acid groups, derivatives of sulfonic acid groups, carboxylic acid groups, derivatives of carboxylic acid groups, phosphonic acid groups, derivatives of phosphonic acid groups, phosphoric acid groups, groups, derivatives of phosphate groups, and/or combinations thereof.

In some embodiments, the sulfonic acid material comprises a derivative of the sulfonic acid material. In some embodiments, the sulfonic acid materials include materials comprising perfluoro-2-(2-fluorosulfonylethoxy)propyl vinyl ether (PSEPVE) of the general formula:

Wherein q is an integer of 1-5.

In some embodiments, derivatives of sulfonic acid materials include materials selected from the group consisting of:

and

in:

Y is selected from _-SO2F and _-SO3H ;

_R is selected from alkyl, substituted alkyl, hydroxyl, alkoxy, fluorine-containing alkenyl, cyano and nitro;

X ₁ is selected from the group consisting of bond, O, S, SO, SO ₂ , CO, NR ₂ and R ₃ ;

X ₂ is selected from O, S and NR ₂ ,

in:

R _is selected from hydrogen, alkyl, substituted alkyl, aryl, and substituted aryl; and

_R is selected from alkylene, substituted alkylene, aryl and substituted aryl;

Ar is selected from aryl and substituted aryl;

B is 1,2-perfluorocyclobutylene;

t is an integer of 1-3;

m is an integer from 0 to 1000;

p is an integer from 1 to 1000; and

q is an integer of 1-5.

In some embodiments, Y is _-SO2F . In some embodiments, Y is _-SO3H .

(E.I.duPont de Nemours and Co.，Wilmington，Delaware，美国)或者类似的材料，包括但不局限于

(DowChemical Company，Midland，Michigan，美国)、

(AsahiChemical Industry Co.，Tokyo，日本)、

(Ballard AdvancedMaterials，Burnaby，British Columbia，加拿大)，或者如在授予Mao等的美国专利第6,559,237号中所述的酸性官能化的全氟亚环丁基聚合物以及如在授予Hamrock等的美国专利第6,833,412号中所述的酸性官能化的氟代聚合物，每篇专利的全部内容以参考的形式引入本文。Thus, in some embodiments, the ionomer may comprise commercially available acidic materials such as

(EIduPont de Nemours and Co., Wilmington, Delaware, USA) or similar materials, including but not limited to

(Dow Chemical Company, Midland, Michigan, USA),

(Asahi Chemical Industry Co., Tokyo, Japan),

(Ballard Advanced Materials, Burnaby, British Columbia, Canada), or acid-functionalized perfluorocyclobutylene polymers as described in U.S. Patent No. 6,559,237 to Mao et al . and as described in U.S. Patent No. 6,559,237 to Hamrock et al . Acid-functionalized fluoropolymers described in No. 6,833,412, each of which is incorporated herein by reference in its entirety.

The term "alkyl" as used herein refers to a C _1-20 (inclusive) linear (ie "straight chain"), branched or cyclic, saturated or at least partially unsaturated and in some cases fully unsaturated (i.e. alkenyl and alkynyl) hydrocarbon chains including, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, octyl, vinyl , propenyl, butenyl, pentenyl, hexenyl, octenyl, butadienyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl and allenyl. "Branched" means an alkyl group in which a lower alkyl group such as methyl, ethyl or propyl, is attached to a linear alkyl chain. "Lower alkyl" refers to an alkyl group having 1 to about 8 carbon atoms, eg, 1, 2, 3, 4, 5, 6, 7 or 8 carbon atoms (ie, C _1-8 alkyl). "Higher alkyl" refers to an alkyl group having from about 10 to about 20 carbon atoms, eg, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 carbon atoms. In certain embodiments, "alkyl" specifically refers to a C _1-8 straight chain alkyl group. In other embodiments, "alkyl" specifically refers to C _1-8 branched chain alkyl.

Alkyl groups may be optionally substituted with one or more alkyl substituents which may be the same or different. The term "alkyl substituent" includes, but is not limited to, alkyl, halo, arylamino, acyl, hydroxy, aryloxy, alkoxy, alkylthio, arylthio, arylalkoxy, arylalkylthio radical, carboxyl, alkoxycarbonyl, oxo and cycloalkyl. One or more oxygen, sulfur, or substituted or unsubstituted nitrogen atoms may optionally be inserted along the alkyl chain wherein the nitrogen substituent is hydrogen, lower alkyl (also referred to herein as "alkaminoalkyl" ) or aryl.

"Cyclic" and "cycloalkyl" refer to non-aromatic mono or polycyclic ring systems having from about 3 to about 10 carbon atoms, eg 3, 4, 5, 6, 7, 8, 9 or 10 carbon atoms. Cycloalkyl groups can optionally be partially unsaturated. Cycloalkyl groups may also be optionally substituted with alkyl substituents, oxygen and/or alkylene as defined herein. One or more oxygen, sulfur or substituted or unsubstituted nitrogen atoms may optionally be inserted along the cycloalkyl chain, wherein the nitrogen substituent is hydrogen, lower alkyl or aryl, thereby providing the heterocyclic group . Representative monocyclic cycloalkyl rings include cyclopentyl, cyclohexyl and cycloheptyl. Polycyclic cycloalkyl rings include adamantyl, octahydronaphthyl, decahydronaphthalene, camphor, camphane and noradamantyl.

"Alkylene" means having from 1 to about 20 carbon atoms, for example 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, A linear or branched divalent aliphatic hydrocarbon group of 18, 19 or 20 carbon atoms. Alkylene groups can be linear, branched or cyclic. The alkylene group can also be optionally unsaturated and/or substituted with one or more "alkyl substituents." One or more oxygen, sulfur, or substituted or unsubstituted nitrogen atoms (also referred to herein as "alkaminoalkyl") may optionally be inserted along the alkylene group, wherein the nitrogen substituents are as previously described alkyl. Examples of alkylene groups include methylene (-CH ₂ -), ethylene (-CH ₂ -CH ₂ -), propylene (-(CH ₂ ) ₃ -), cyclohexylene (-C ₆ H ₁₀ -), -CH=CH—CH=CH-, -CH=CH-CH ₂ -, -(CH ₂ ) _q -N(R)-(CH ₂ ) _r -, wherein q and r are each independently is an integer from 0 to about 20, such as 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20, and R is hydrogen or lower alkyl, methylenedioxy (-O-CH2 _- O-) and ethylenedioxy (-O-( _CH2 ) _2- O-). The alkylene group can have about 2 to about 3 carbon atoms and can also have 6-20 carbon atoms.

The term "aryl" as used herein refers to an aromatic substituent, which may be a single aromatic ring or multiple aromatic rings fused together, linked covalently, or linked to a common group such as a methylene or ethylene moiety. The common linking group may also be a carbonyl group (such as in benzophenone) or oxygen (such as in diphenyl ether) or nitrogen (such as in diphenylamine). The term "aryl" specifically includes heterocyclic aromatic compounds. Aromatic rings may especially include phenyl, naphthyl, biphenyl, diphenyl ether, diphenylamine and benzophenone. In particular embodiments, the term "aryl" means a cyclic aromatic ring comprising about 5 to about 10 carbon atoms, such as 5, 6, 7, 8, 9 or 10 carbon atoms, and includes 5- and 6-membered hydrocarbon and heterocyclic aromatic ring.

Aryl may be optionally substituted with one or more aryl substituents which may be the same or different, wherein "aryl substituent" includes alkyl, aryl, aralkyl, hydroxy, alkoxy, aryloxy, Arylalkoxy, carboxyl, acyl, halogen, nitro, alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, acyloxy, amido, aroylamino, carbamoyl, alkylaminomethyl Acyl, dialkylcarbamoyl, arylthio, alkylthio, arylene and -NR'R", wherein R' and R" are each independently hydrogen, alkyl, aryl and aralkyl.

Specific examples of aryl groups include, but are not limited to, cyclopentadienyl, phenyl, furan, thiophene, pyrrole, pyran, pyridine, imidazole, benzimidazole, isothiazole, isoxazole, pyrazole, pyrazine, tris Oxyzine, pyrimidine, quinoline, isoquinoline, indole, carbazole, etc.

The term "arylene" refers to a divalent group derived from a monocyclic aromatic hydrocarbon or a polycyclic aromatic hydrocarbon by removing hydrogen atoms from two carbon atoms on an aromatic ring. Examples of "arylene" groups include, but are not limited to, 1,2-phenylene, 1,3-phenylene, and 1,4-phenylene.

As used herein, the terms "substituted alkyl", "substituted cycloalkyl", "substituted alkylene", "substituted aryl" and "substituted arylene" include alkyl, alkylene, Alkyl and aryl, wherein one or more atoms or functional groups of an alkyl, alkylene, aryl or arylene group are replaced by another atom or functional group (including, for example, halogen, aryl, alkyl, alkoxy, hydroxy , nitro, amino, alkylamino, dialkylamino, sulfate and mercapto) substitutions.

"Alkoxy" or "alkoxyalkyl" means an alkyl-O- group in which the alkyl group is as previously described. The term "alkoxy" as used herein may refer to a C _1-20 (inclusive) linear, branched or cyclic, saturated or unsaturated oxy-hydrocarbyl chain, including, for example, methoxy, ethoxy, propane Oxy, isopropoxy, butoxy, t-butoxy and pentoxy.

As used herein, the terms "halo", "halide" or "halogen" refer to fluoro, chloro, bromo and iodo groups.

The term "hydroxyl" refers to a -OH group.

The term "hydroxyalkyl" refers to the substitution of an alkyl group with an -OH group.

The term "nitro" refers to a _-NO2 group.

In some embodiments, the processing of the precursor material comprises a process selected from: (a) a curing process; (b) a chemical modification process; (c) a network forming process and (d) a combination of these processes. In some embodiments, the curing process comprises a process selected from thermal processes, photochemical processes, and irradiation processes. In some embodiments, the irradiating process includes irradiating the liquid precursor material with radiation, wherein the radiation is selected from gamma rays and electron beams. In some embodiments, the chemical modification process includes a cross-linking process. Methods for the radiolysis of fluoropolymers, including perfluoropolyether materials, are given in JS Forsythe et al ., Prog. Polym. Sci., 25, 101-136 (2000), which is incorporated herein by reference in its entirety.

In addition, PCT International Application Publication WO 99/61141 by Mao et al. describes a method of making cross-linked polymers suitable for use in ion-conducting membranes such as proton exchange membranes by (a) combining two or more acid halide groups (b) crosslink a polymer having pendant amide groups with a crosslinking agent that incorporates two or more amide groups. In addition, Buchi et al ., J. Electrochem. Soc., 142(9), 3004 (1995) disclose the preparation of proton exchange membranes by sulfonating cross-linked polyolefin-polystyrene copolymers which pass through during polymerization Add divinylbenzene to crosslink. US Patent No. 5,438,082 to Helmer-Metzmann et al. discloses a method of crosslinking sulfonated aromatic polyetherketones with crosslinking agents containing amine functional groups. Additionally, U.S. Patent No. 5,468,574 to Ehrenberg et al. and PCT International Application Publication WO 97/19,480 to Graham et al. disclose that certain sulfonated polymers will form bonds directly between the sulfonic acid groups when heated, but this approach exhibits The sulfonic acid groups are sacrificed, resulting in a loss of acidity in the membrane. The entire contents of the aforementioned patents, literature and published patent applications are incorporated herein by reference.

Accordingly, in some embodiments, the present invention provides a polymer electrolyte comprising a 100% cured liquid precursor material as defined above, wherein the 100% cured liquid precursor material comprises from about 70% to about 100% by weight of polymerizable material

In some embodiments, the polymer electrolytes of the present invention have an equivalent weight, wherein the equivalent weight is selected from an equivalent weight of less than about 1500 and greater than about 1000, an equivalent weight of less than about 1000 and greater than about 800, an equivalent weight of less than about 800 and greater than about In the equivalent weight of 500 and the equivalent weight below 500.

Furthermore, in some embodiments, the present invention provides electrochemical cells comprising polymer electrolytes prepared from 100% cured liquid precursors. In some embodiments, the electrochemical cell is selected from a fuel cell, a chlor-alkali cell, and a battery.

和其它PEM材料性能最佳。将醇结合入

类材料中使材料更亲水，这会导致在较低的相对湿度下良好的传导率和/或在较高温度下降低的失水量。路线11中提供了一个实例，其提供了用醋酸乙烯酯聚合类材料组分的方法。简单的水解反应将醋酸酯转化成醇，同时在质子传导化合物上获得磺酸基团。材料上的后氟化可以给全氟材料提供化学和热稳定性。Furthermore, when the relative humidity is high, such as about 90%,

and other PEM materials perform best. Incorporate alcohol into

In such materials, the material is made more hydrophilic, which results in good conductivity at lower relative humidity and/or reduced water loss at higher temperatures. An example is provided in scheme 11, which provides polymerization with vinyl acetate Method for Class Material Components. A simple hydrolysis reaction converts the acetate to the alcohol while simultaneously obtaining a sulfonic acid group on the proton-conducting compound. Post-fluorination on the material can provide chemical and thermal stability to the perfluorinated material.

的另一个局限是其低的酸含量。

的酸含量没有目前以商业级别获得的高，因为通过增加结合入TFE/PSEPVE共聚物中的PSEPVE分数而增加的酸含量导致当量重量的降低了，这是因为氟代乙烯醚在聚合期间趋向于经历β-裂解反应而导致分子量降低。参见Romack，T.J.和DeSimone，J.M.，Macromolecules，28，8429-8431(1995)，该文献全部内容以参考的形式引入本文。因此，随着

的酸含量增加，聚合物的分子量降低并且危害机械性质。这种直链、低分子量、高酸含量的

类材料具有不良的成膜性质并且变成水溶性的—不可接受的性质。由于这种在用来制造

的反应化学中的限制，供应商销售的

级别都不含保证非常高的质子传导率所需的足够高的酸含量。事实上，研究最广泛的商业级

具有1100的当量重量，其在完全水化的条件和室温下只有0.083S/cm的质子传导率。参见Mauritz，K.A.和Moore，R. B.，Chem.Rev.，104，4535-4585(2004)，该文献全部内容以参考的形式引入本文。本发明材料解决了这些不足并且产生新型的PEM，其具有更高的传导率、更加热稳定的、更有选择性的、更加机械坚固的并且结合了允许独立控制膜性质的模块化设计。

Another limitation of is its low acid content.

The acid content is not as high as currently obtained in commercial grades because the increased acid content by increasing the fraction of PSEPVE incorporated into the TFE/PSEPVE copolymer results in a decrease in equivalent weight because fluorovinyl ethers tend to tend during polymerization to undergoes a β-cleavage reaction resulting in a decrease in molecular weight. See Romack, TJ and DeSimone, JM , Macromolecules, 28, 8429-8431 (1995), which is incorporated herein by reference in its entirety. Therefore, with

As the acid content increases, the molecular weight of the polymer decreases and the mechanical properties are compromised. This linear, low molecular weight, high acid content

Such materials have poor film forming properties and become water soluble—unacceptable properties. Since this is used to manufacture

Restrictions in the reaction chemistry that suppliers sell for

None of the grades contain a high enough acid content to guarantee very high proton conductivity. In fact, the most widely studied commercial-grade

With an equivalent weight of 1100, it has a proton conductivity of only 0.083 S/cm at room temperature under fully hydrated conditions. See Mauritz, KA and Moore, R. B. , Chem. Rev., 104, 4535-4585 (2004), which is hereby incorporated by reference in its entirety. The inventive material addresses these deficiencies and results in a new type of PEM that is more conductive, more thermally stable, more selective, more mechanically robust and incorporates a modular design that allows independent control of membrane properties.

的形貌可以看作是包埋在聚四氟乙烯类母体中的酸基团的孤立的簇。质子可以在簇内从酸基团到酸基团跳跃，但是为了使质子在宏观上传输通过PEM，它必须以水合氢离子的形式穿过亲水通道从一个酸簇迁移到下一个簇。即，为了使

是高度质子传导性的，需要存在水量的阀值。为了使

是高度质子传导性的，要求其是水合的(参见Mauritz，K.A. 和Moore，R.B.，Chem.Rev.，104，4535-4585(2004))，在高于水沸点的温度下使用

基燃料电池时，这种要求造成了实际的实施障碍。另外，不受任何特定的理论束缚，据信在与PEM交联的本发明液态前体中实现的非常高的酸含量形成酸基连续区，这些连续区彼此处于质子跳跃距离内。如此，质子可以在宏观上传输通过膜，而不需要与商业级

或者当量重量>550的任何其它的PEM材料相关的含水量。Without being bound by any particular theory, it is believed that the high conductivity of the material of the present invention results from substantially the same different proton conduction mechanisms at work. According to most reports, see for example Mauritz, KA and Moore, RB , Chem. Rev., 104, 4535-4585 (2004),

The morphology of can be seen as isolated clusters of acid groups embedded in the PTFE-like matrix. A proton can hop from acid group to acid group within a cluster, but for a proton to transport macroscopically through the PEM, it must migrate from one acid cluster to the next in the form of a hydronium ion through hydrophilic channels. That is, in order to make

Being highly proton conductive, a threshold amount of water is required to be present. because

It is highly proton conductive, requiring it to be hydrated (see Mauritz, KA and Moore, RB , Chem.Rev., 104, 4535-4585 (2004)), used at temperatures above the boiling point of water

This requirement creates a practical barrier to implementation when using fuel cells as the basis. Additionally, without being bound by any particular theory, it is believed that the very high acid content achieved in the liquid precursor of the invention crosslinked with PEM forms a continuum of acid groups that are within proton hopping distance of each other. In this way, protons can be transported through the membrane macroscopically without the need for commercial-grade

Or any other PEM material with an equivalent weight >550 relative to the moisture content.

In conclusion, the inventive materials can be used in conventional electrochemical battery applications, such as automotive applications, as well as, for example, portable power sources for electronic devices. In some embodiments, the inventive materials exhibit improved mechanical stability at elevated temperatures. In some embodiments, the materials of the invention exhibit reduced permeability to alkyl alcohols such as methanol. In some embodiments, the inventive materials provide increased electrochemical cell performance at lower relative humidity and increased proton exchange membrane hydrophilicity.

II. Method for Preparing Patterned Proton Exchange Membrane

In some embodiments, the present invention provides methods of making patterned proton exchange membranes. One such embodiment is provided in Figures 1A-1B.

Referring now to FIG. 1A, a patterned substrate, such as a mold 100, is provided. The mold 100 may include materials selected from inorganic materials, organic materials, and combinations thereof. In some embodiments, the mold 100 has a predetermined geometry 102 , wherein the predetermined geometry 102 has a macroscopic area 104 . For example, as shown in FIG. 1A, the predetermined geometric shape 102 includes a rectangular substrate 106 having a first planar surface 108, wherein the first planar surface 108 further comprises a plurality of Structural features 110 are represented by pegs protruding from planar surface 108 .

Furthermore, those of ordinary skill in the art upon reading the present disclosure will understand that the plurality of structural features 110 may take any form including, but not limited to, pegs, fluted pegs, curled columns, patterns, walls and intersecting surfaces (not shown). Thus, proton exchange membranes prepared by the methods of the present invention can be fabricated in various geometries, can have a large number of channels and/or can contain controlled or variable surface areas.

In some embodiments, proton exchange membranes prepared by the methods of the invention have a greater "active surface" area than a "macroscopic surface" area. Thus, in some embodiments, the predetermined geometry 102 includes a plurality of structures 110 having a surface area greater than the macroscopic area 104 of the mold 100 . In some embodiments, the surface area 112 of the plurality of structures 110 is at least about two times to about 100 times the macroscopic surface area 104 of the mold 100 . In some embodiments, the predetermined geometry 102 includes a plurality of structures 110 having a surface area 112 that is at least twice the macroscopic surface area 104 of the mold 100 . In some embodiments, the predetermined geometry 102 includes a plurality of structures 110 having a surface area 112 that is at least five times the macroscopic surface area 104 of the mold 100 . In some embodiments, the predetermined geometry 102 includes a plurality of structures 110 having a surface area 112 that is at least 20 times the macroscopic surface area 104 of the mold 100 . In some embodiments, the predetermined geometry 102 includes a plurality of structures 110 having a surface area 112 that is at least 80 times the macroscopic surface area 104 of the mold 100 .

Referring now to FIGS. 1A and 1B , liquid precursor material 114 is brought into contact with mold 100 . The liquid precursor material 114 may comprise any of the liquid precursor materials disclosed above, ie, the liquid precursor material may comprise proton-conducting materials, precursors of proton-conducting materials, and combinations thereof. Liquid precursor material 114 is processed through processing T _r to form processed liquid precursor material 116 as shown in FIG. 1B .

In some embodiments, the treatment process T _r comprises a process selected from a curing process, a chemical modification process, a network forming process, a solvent evaporation process, and combinations thereof. In some embodiments, the curing process comprises a process selected from thermal processes, photochemical processes, and irradiation processes. Additionally, in some embodiments, the irradiating process includes irradiating the liquid material with radiation, wherein the radiation is selected from gamma rays and electron beams. In some embodiments, the chemical modification process includes a cross-linking process.

Referring now to FIG. 1B, the processed liquid precursor material 116 is removed from the mold 100, thereby providing a freestanding proton exchange membrane 118 comprising a plurality of structural features 120 corresponding to the plurality of structural features 110 of the mold 100. . In some embodiments, plurality of structures 110 and 120 has dimension 122 that is less than 10 millimeters. In some embodiments, plurality of structures 110 and 120 has dimension 122 that is less than 1 millimeter. In some embodiments, the plurality of structures 110 and 120 have a dimension 122 that is less than 100 microns. In some embodiments, the plurality of structures 110 and 120 have a dimension 122 of less than 10 microns. In some embodiments, the plurality of structures 110 and 120 have a dimension 122 of less than 1 micron. In other words, in some embodiments, a single structure comprising a plurality of structures 110 and 120 may have a height ranging from less than about 10 millimeters to less than about 1 micron and/or a dimension ranging from less than about 10 millimeters to less than about 1 micron. 1 micron range width.

Accordingly, in some embodiments, the present invention provides a method of making a patterned polymer electrolyte, the method comprising:

(a) contacting a liquid precursor material with a patterned substrate, wherein the patterned substrate has a predetermined geometry and macroscopic surface area; and

(b) processing the liquid precursor material to form a patterned polymer electrolyte.

In some embodiments, the liquid precursor material includes a material selected from the group consisting of proton-conducting materials, precursors of proton-conducting materials, and combinations thereof.

In some embodiments, the patterned substrate includes a material selected from the group consisting of inorganic materials, organic materials, and combinations thereof.

In some embodiments, the predetermined geometry includes a non-planar geometry. In some embodiments, the non-planar geometric shape has a predetermined dimension selected from a dimension of less than about 10 millimeters and greater than about 1 millimeter, a dimension of less than about 1 millimeter and greater than about 100 microns, a dimension of less than about 100 microns and greater than about Features in dimensions of 10 microns, dimensions of less than about 10 microns and greater than about 1 micron, and sizes of less than about 1 micron.

In some embodiments, the predetermined geometry is defined by one of the catalyst layer and the electrode material comprising the membrane electrode assembly. In some embodiments, the predetermined geometry is defined by the membrane electrode assembly. In some embodiments, the predetermined geometry includes a structure selected from the group consisting of patterns, pegs, walls, intersecting surfaces, and curled cylinders.

In some embodiments, the predetermined geometry includes structures with a surface area greater than the macroscopic surface area of the patterned substrate. In some embodiments, the surface area of the structures is at least about two times to about 100 times the macroscopic surface area of the patterned substrate.

In some embodiments, the processing of the liquid precursor material comprises a process selected from the group consisting of: (a) a curing process; (b) a chemical modification process; (c) a network forming process; (d) a solvent evaporation process; and (e) their combination.

Accordingly, in some embodiments, the invention provides patterned proton exchange membranes prepared by the methods of the invention. In some embodiments, the patterned proton exchange membrane comprises a material having an equivalent weight selected from an equivalent weight of less than about 1500 and greater than about 1000, an equivalent weight of less than about 1000 and greater than about 800, an equivalent weight of less than about 1000 and greater than about 800, an equivalent weight of less than about 800 and greater than about 500 in the equivalent weight and 500 or less in the equivalent weight.

In some embodiments, the invention provides electrochemical cells comprising a patterned proton exchange membrane of the invention. In some embodiments, the electrochemical cell is selected from fuel cells, chlor-alkali cells, and batteries.

Examples of proton exchange membranes prepared by the method of the present invention are provided in Figures 2A and 2B, which show a scanning electron micrograph of a PEM with a sharkskin pattern before hydrolysis and a scanning electron micrograph of a PEM with a sharkskin pattern after hydrolysis, respectively photo. Sharkskin patterns were prepared as described in Example 7. The characteristic dimensions of the sharkskin pattern, ie the structures described above, in this particular example are about 2 microns in width and about 8 microns in height. By using the sharkskin pattern, the surface area of the patterned PEM is about 5 times that of a flat unpatterned PEM with the same macroscopic dimensions. As shown in the scanning electron micrograph provided in Figure 2A, high-fidelity structural features were obtained by the method of the present invention. Furthermore, as shown in the scanning electron micrograph provided in Fig. 2B, the pattern swelled after the PEM underwent hydrolysis, but the structural features were still evident.

In some embodiments, the predetermined geometry of the mold 100 (e.g., element 102 of FIG. 1A ) and the geometry of the PEM formed therein is determined by a catalyst tie layer (as provided in FIG. Electrode materials for membrane electrode assemblies are defined. Furthermore, because the liquid precursor material of the present invention, such as liquid precursor material 114 of FIG. 1A is a liquid, it is pourable. Thus, the liquid precursor material 114 can be poured into an existing structure, such as that defined by the electrode material.

For example, referring now to FIGS. 3A and 3B , a first electrode material 300 and a second electrode material 302 are operably positioned in a spatial arrangement that creates a gap 304 therebetween. Liquid precursor material 306 is poured into gap 304 . Liquid precursor material 306 may include any of the liquid precursor materials disclosed above. The liquid precursor material 306 is then processed by a treatment process _Tr to form a proton exchange membrane 308 that remains in a functional location between the first electrode material 300 and the second electrode material 302 in some embodiments. Thus, in some embodiments, a liquid precursor material such as 306 is injected directly into a preformed cavity, such as the void 304 formed between the first electrode material 300 and the second electrode material 302, followed by the process T _r .

Referring again to FIGS. 3A and 3B , in some embodiments, prior to pouring the liquid precursor material 306 into the gap 304, the first electrode material 300 is coated with a first catalyst material 310 and the second electrode material is coated with a second catalyst material 312. Two electrode materials 302 .

In some embodiments, the proton exchange membrane 308 comprises a material having an equivalent weight selected from the group consisting of an equivalent weight less than about 1500 and greater than about 1000, an equivalent weight less than about 1000 and greater than about 800, less than about 800, and In an equivalent weight of greater than about 500 and in an equivalent weight of less than 500. The conductivity of representative PEMs prepared from the liquid materials of the invention with different equivalent weights under fully hydrated conditions are provided in Figures 4 to 8 .

III. Method for preparing polymer electrolytes comprising equivalent weight gradients

的高当量重量PEM对甲醇是不太渗透的。但是，这种材料表现出较低的传导率。低当量重量的PEM相对于具有可比组分的高当量重量材料的PEM给出更高的传导率值，但是允许高的甲醇渗透性，这会导致功率密度的剧烈降低。In addition, the synthesis methods of the liquid precursor materials disclosed herein can be altered to create compositional gradients, thereby tailoring properties and improving the performance of the PEMs of the present invention. Existing PEMs typically contain materials with a single equivalent weight (EW), which leads to a trade-off between power density and methanol permeability. For example, based on

The high equivalent weight PEM is not very permeable to methanol. However, this material exhibits low conductivity. Low equivalent weight PEMs give higher conductivity values relative to PEMs of higher equivalent weight materials of comparable composition, but allow high methanol permeability, which results in a drastic reduction in power density.

The present invention provides PEMs with equivalent weight gradients. With the equivalent weight gradients disclosed herein, optimal performance can be achieved in both areas (methanol permeability and conductivity). For example, using a material with a higher equivalent weight at the anode provides a PEM with low methanol permeability, while including a material with a lower equivalent weight throughout the PEM profile provides higher power density.

类材料。但是，液体材料902a至902f不局限于高T_g材料，并且在一些实施方案中，液体材料902a至902f包括氟代或者基于全氟弹性体的材料或者本文中公开的任何材料。Referring now to FIG. 9A, the fabrication of a proton exchange membrane 900 from a variety of liquid materials 902 is illustrated. In this embodiment, the plurality of liquid materials 902 includes a plurality of liquid materials 902a through 902f. In some embodiments, the liquid materials 902a-902f include high glass transition temperature (T _g )

class material. However, the liquid materials 902a-902f are not limited to high _Tg materials, and in some embodiments, the liquid materials 902a-902f include fluoro or perfluoroelastomer-based materials or any materials disclosed herein.

In some embodiments, each liquid material, e.g., 902a, 902b, 902c, 902d, 902e, and 902f, has a different equivalent weight (e.g., _EWa , _EWb , _EWc , _EWd , _EWe, and _EWf , respectively ( not shown)). As used herein, the term "equivalent weight" refers to the weight of acidic material comprising one equivalent of acid functional groups. Accordingly, the equivalent weight of the polymer electrolyte as disclosed herein is the value of the equivalent of acidic groups of the polymer electrolyte divided by the weight of the polymer electrolyte. Furthermore, the term "different equivalent weight" as used herein refers to an equivalent weight, eg EW _a , which differs from another equivalent weight (eg EW _b ) by about 50 g/mol. For example, an equivalent weight of about 800 is considered to be different from an equivalent weight of about 750.

Referring again to FIG. 9A, the liquid material closest to the anode 904, layer 902a, has a higher equivalent weight than 902b-902f. In some embodiments, the equivalent weights of the liquid materials 902a to 902f have the following trend: EW _a >EW _b >EW _c >EW _d >EW _e >EW _f , with the liquid material 902f closest to the cathode 906 having the lowest equivalent weight .

In some embodiments, at least one of the liquid materials 902a, 902b, 902c, 902d, 902e, and 902f has an equivalent weight of less than 1500. In some embodiments, at least one of the liquid materials 902a, 902b, 902c, 902d, 902e, and 902f has an equivalent weight of less than 1000. In some embodiments, at least one of the liquid materials 902a, 902b, 902c, 902d, 902e, and 902f has an equivalent weight of less than 800. In some embodiments, at least one of the liquid materials 902a, 902b, 902c, 902d, 902e, and 902f has an equivalent weight of less than 500. The conductivity of representative PEMs prepared from the liquid materials of the invention with different equivalent weights under fully hydrated conditions are provided in Figures 4 to 8 .

Referring now to FIG. 9B, in some embodiments, in order to reduce the methanol permeability of the PEM 900 at the anode 904, a high equivalent weight liquid material, such as 902a having an equivalent weight _EWa , is disposed, such as applied or spin-coated to a substrate (e.g., the anode 904 ) to form a layer of liquid material 902a on the anode 904, followed by a treatment process _Tr to form a treated liquid material 908a. Treated liquid material 908a is coated with a lower equivalent weight liquid material (eg, 902b) having an equivalent weight _EWb , and then processed to form treated liquid material 908b (not shown). This step is repeated as needed to form a PEM 900 with an equivalent weight gradient (eg, EW _a to EW _f ). Thus, in some embodiments, the processed liquid material closest to cathode 906, eg, 908f (not shown), has the lowest equivalent weight, eg, _EWf . Thus, the present method can provide a reduction in methanol permeability at the anode 904 and can facilitate easier transport of protons across the cross-section of the PEM 900 .

Accordingly, in some embodiments, PEM 900 comprises a multilayer polymer electrolyte, wherein the multilayer polymer electrolyte comprises at least one first layer of a first polymer electrolyte comprising a material having a first equivalent weight and at least one second A second layer of polymer electrolyte comprising a material having a second equivalent weight. In some embodiments, the multilayer polymer electrolyte has an equivalent weight gradient.

Accordingly, in some embodiments, the present invention provides methods of preparing polymer electrolytes having multiple equivalent weights, the methods comprising:

(a) applying to the substrate a first liquid precursor material having a first equivalent weight;

(b) treating said first liquid precursor material to form a first layer of treated liquid precursor material on the substrate;

(c) applying a second liquid precursor material having a second equivalent weight to the first layer of treated liquid precursor material on the substrate; and

(d) treating the second liquid precursor material to form a polymer electrolyte having a plurality of equivalent weights.

In some embodiments, both the first liquid precursor material and the second liquid precursor material are selected from the group consisting of proton-conducting materials, precursors of proton-conducting materials, and combinations thereof. In some embodiments, the first equivalent weight is greater than the second equivalent weight.

In some embodiments, the substrate is selected from an anode and a cathode. In some embodiments, the treatment of the first liquid precursor material, the second liquid precursor material, and the plurality of liquid precursor materials is selected from a curing process, a chemical modification process, a network forming process, a solvent evaporation process, and combinations thereof .

In some embodiments, the method includes repeating steps (c) through (d) with a predetermined plurality of liquid precursor materials having a plurality of equivalent weights to form a polymer electrolyte having a plurality of equivalent weights, wherein the plurality of The liquid precursor material is selected from the group consisting of proton-conducting materials, precursors of proton-conducting materials, and combinations thereof. In some embodiments, the second equivalent weight is greater than the plurality of equivalent weights.

Accordingly, in some embodiments, the invention provides polymer electrolytes having multiple equivalent weights prepared by the methods of the invention. In some embodiments, the present invention provides electrochemical cells comprising a polymer electrolyte of the present invention having an equivalent weight gradient. In some embodiments, the electrochemical cell is selected from fuel cells, chlor-alkali cells, and batteries.

The performance of the proton exchange membranes of the present invention can be evaluated by measuring conductivity, power density, durability and especially lifetime.

IV. Methods of Preparing Membrane Electrode Assembly (MEA)

The present invention also provides a method of making a membrane electrode assembly (MEA). In some embodiments, a method of making a membrane electrode assembly comprises using the liquid precursor materials described herein to make a processable catalyst ink composition. Furthermore, in some embodiments, the method of making a membrane electrode assembly comprises providing a proton exchange membrane by the method of the invention, coating said proton exchange membrane with a treatable catalyst ink composition, thereby forming a coated proton exchange membrane, and In some embodiments, an electrode material is applied to the coated proton exchange membrane.

IV.A. Method of Making Disposable Catalyst Ink Compositions

In some embodiments, the present disclosure describes a method of making a processable catalyst ink composition, the method comprising:

(a) providing a liquid precursor material; and

(b) mixing said liquid precursor material with a catalyst to form a disposable catalyst ink composition.

In some embodiments, the liquid precursor material includes a liquid perfluoropolyether material. In some embodiments, the liquid perfluoropolyether material includes end groups, wherein the end groups are chemically stable after curing. In some embodiments, the chemically stable end groups are selected from aryl end groups and fluorovinyl ether end groups. In some embodiments, the aryl end groups include styrene end groups.

In some embodiments, the method further includes mixing the liquid precursor material with a monomer (eg, vinyl monomer) and a crosslinker. In some embodiments, the vinyl monomer includes a proton conducting material. In some embodiments, the proton-conducting species is selected from acidic materials and precursors of acidic materials.

In some embodiments, the processable catalyst ink composition includes a catalyst. In some embodiments, the catalyst includes a metal selected from the group consisting of platinum, ruthenium, molybdenum, chromium, and combinations thereof. In some embodiments, the catalyst is selected from one of platinum catalysts and platinum alloy catalysts. In some embodiments, the processable catalyst ink composition includes an electrode material. In some embodiments, the electrode material comprises carbon black.

In some embodiments, the method includes treating the treatable catalyst ink composition. In some embodiments, the processing of the treatable catalyst ink composition comprises a processing selected from the group consisting of a curing process, a chemical modification process, a network forming process, a solvent evaporation process, and combinations thereof.

Accordingly, in some embodiments, the present invention provides a processable catalyst ink composition prepared by the methods described herein.

IV.B. Methods of Applying Treatable Catalyst Ink Compositions to Substrates

In some embodiments, the present invention provides methods of applying a treatable catalyst ink composition to a substrate. In some embodiments, the substrate includes electrode material. In some embodiments, the substrate comprises a proton exchange membrane.

Referring now to FIG. 10A , in some embodiments, the processable catalyst ink composition 1000 described immediately above is applied to an electrode material 1002 . In some embodiments, electrode material 1002 includes carbon cloth. In some embodiments, electrode material 1002 includes carbon paper. The treatable catalyst ink composition 1000 is subsequently treated by a treatment process T _r to form a catalyst strip (not shown), which provides good contact with the electrode material 1002 .

Referring now to FIG. 10B , in some embodiments, a treatable catalyst ink composition 1000 is applied to a patterned proton exchange membrane 1004 . The treatable catalyst ink composition 1000 is subsequently treated by a treatment process T _r to form a catalyst belt (not shown), which provides good contact with the proton exchange membrane 1004 .

The method used to coat one or both of the electrode 1002 and the proton exchange membrane 1004 can be selected from the group including but not limited to chemical vapor deposition (CVD), electrospray, electric field desorption, radio frequency plasma enhanced CVD, flame spray deposition , inkjet printing or pulsed laser desorption methods. In some embodiments, the method includes treating the treatable catalyst ink composition. In some embodiments, the processing of the treatable catalyst ink composition comprises a processing selected from the group consisting of a curing process, a chemical modification process, a network forming process, a solvent evaporation process, and combinations thereof.

The methods described in this invention can be implemented independently for use with different MEAs. That is, in one membrane electrode assembly, the method of the present invention can be used to coat the electrode material, and in the other membrane electrode assembly, the method of the invention can be used to coat the proton exchange membrane. Furthermore, the same membrane electrode assembly can be prepared using both methods, such as those described in FIG. 10A and FIG. 10B , respectively.

IV.C. Method for Conformally Coating Proton Exchange Membranes

In some embodiments, the present invention provides conformal coating of a proton exchange membrane with at least one of a treatable catalyst ink composition and an electrode material. "Conformally coated" means that a coating, eg, of a treatable catalyst ink composition and/or electrode material, is in conductive contact with a feature, eg, comprising a proton exchange membrane, so as to conform to the geometry of its feature.

Referring now to FIG. 11A, in some embodiments, a patterned PEM 1100 is conformally coated with a processable catalyst ink composition 1102, followed by coating with an electrode material 1104, such as carbon black, thereby forming a planarization of the electrode material 1104. Surface 1106. In some embodiments, the treatable catalyst ink composition 1102 is then processed through a treatment process _Tr . When optionally located in a membrane electrode assembly (not shown), the flat coating of electrode material allows the membrane electrode assembly to have a flat surface on at least one side thereof.

Referring now to FIG. 11B , in some embodiments, a patterned PEM 1100 is conformally coated with a treatable catalyst ink composition 1102 followed by electrode material 1104 to form a conformal surface 1108 of the electrode material 1104 . In some embodiments, the treatable catalyst ink composition 1102 is then processed through a treatment process _Tr .

Referring now to FIG. 11C , in some embodiments, a patterned PEM 1100 is conformally coated with a treatable catalyst ink composition 1102 to form a planarized surface 1110 of the treatable catalyst ink composition 1102 . It is then coated with electrode material 1104 , forming a conformal surface 1106 of electrode material 1104 . In some embodiments, the treatable catalyst ink composition 1102 is then processed through a treatment process _Tr . When operatively placed in a membrane electrode assembly (not shown), the flat coating of electrode material allows the membrane electrode assembly to have a flat surface on at least one side thereof.

Accordingly, in some embodiments, the method includes conformally applying a treatable catalyst ink composition onto at least one of a proton exchange membrane and an electrode material.

By way of example, scanning electron micrographs of a patterned PEM conformally coated with a catalyst by using electrospray deposition techniques are shown in Figures 12A and 12B. Furthermore, a scanning electron micrograph of a patterned PEM conformally coated with a catalyst by using a vapor deposition technique is represented in FIG. 13 . The preparation of each of these PEMs is described in Example 8.

IV.D. Method of Preparing Membrane Electrode Assembly (MEA)

The invention also provides a method for preparing the membrane electrode assembly. In some embodiments, the method of making a membrane electrode assembly comprises the methods of making a proton exchange membrane, making a treatable catalyst ink composition, applying a treatable catalyst ink composition to a substrate, and conformally coating a proton exchange membrane of the present invention at least one of the .

Accordingly, in some embodiments, the method of forming a membrane electrode assembly comprises:

(a) providing a proton exchange membrane, wherein said proton exchange membrane is prepared from a liquid precursor material as described herein;

(b) providing a first catalyst material and a second catalyst material;

(c) providing a first electrode material and a second electrode material; and

(d) operatively disposing said proton exchange membrane, said first and second catalyst materials, and said first and second electrode materials in conductive communication to form a membrane electrode assembly.

Referring now to FIG. 14A, an embodiment of the present method for forming a membrane electrode assembly is provided. With continued reference to Figure 14A, a proton exchange membrane 1400 is provided. In some embodiments, the proton exchange membrane 1400 includes a three-dimensional geometry as shown in Figure 14A. In some embodiments, first catalyst material 1402 and second catalyst material 1404 are in conformal contact with proton exchange membrane 1400 . The first electrode material 1406 is in conformal contact with the first catalyst material 1402 . The second electrode material 1408 is in conformal contact with the second catalyst material 1404 . In some embodiments, first electrode material 1406 and second electrode material 1408 include planar geometries. In some embodiments, the individual components of the membrane electrode assembly can be treated by a treatment process _Tr to provide good contact and mechanical stability between the individual components.

Accordingly, the present invention provides a membrane electrode assembly comprising a three-dimensional proton exchange membrane and a two-dimensional electrode conformally loaded with a catalyst. Three-dimensional means, for example, that the proton exchange membrane has features that protrude from the planar surface (see, eg, plurality of structural features 120 in FIG. 1B ). Two-dimensional means, for example, that the electrode material comprises a planar surface in conductive communication with the proton exchange membrane (see, eg, first electrode material 1406 and second electrode material 1408 of Figure 14A).

Referring now to Figure 14B, a proton exchange membrane 1400 is provided. In some embodiments, the proton exchange membrane 1400 comprises a three-dimensional geometry as shown in FIG. 14B , wherein the three-dimensional geometry includes a plurality of depressions 1410 . In some embodiments, first catalyst material 1412 and second catalyst material 1414 are operatively located within recess 1410 . The first electrode material 1406 is in conformal contact with the first catalyst material 1412 . The second electrode material 1408 is in conformal contact with the second catalyst material 1414 . In some embodiments, the first electrode material 1406 and the second electrode material 1408 include planar-two-dimensional geometries. In some embodiments, the individual components of the membrane electrode assembly can be treated by a treatment process _Tr to provide good contact and mechanical stability between the individual components. Accordingly, the present invention provides a membrane electrode assembly comprising a three-dimensional proton exchange membrane and a two-dimensional electrode that does not conformally support the catalyst.

Referring now to FIG. 15, a proton exchange membrane 1500 is provided. In some embodiments, the proton exchange membrane 1500 comprises a three-dimensional geometry having a plurality of depressions 1502 . In some embodiments, first catalyst material 1504 and second catalyst material 1506 are in conformal contact with proton exchange membrane 1500 . In some embodiments, first electrode material 1508 is located within recess 1502 and is in operative contact with first catalyst material 1504 . In some embodiments, second electrode material 1510 is located within recess 1502 and is in operable contact with catalyst material 1506 . In some embodiments, the individual components of the membrane electrode assembly can be treated by a treatment process _Tr to provide good contact and mechanical stability between the individual components. Accordingly, the present invention provides a membrane electrode assembly comprising a three-dimensional proton exchange membrane and a three-dimensional electrode conformally loaded with a catalyst.

In some embodiments, a proton exchange membrane, such as 1400 of Figures 14A and 14B and 1500 of Figure 15, is formed by the methods described herein. In some embodiments, proton exchange is formed by operatively disposing a liquid precursor material between two electrode materials, such as first electrode material 1508 and second electrode material 1510 of FIG. membrane.

Accordingly, in some embodiments, the present invention provides a method of making a membrane electrode assembly, the method comprising:

(a) providing a first electrode material;

(b) providing a second electrode material;

(c) disposing said first electrode material and second electrode material in a spatial arrangement forming a gap between said first electrode material and second electrode material;

(d) disposing a liquid precursor material in the space between said first electrode material and second electrode material; and

(e) processing the liquid precursor material to form a membrane electrode assembly.

In some embodiments, the liquid precursor material is selected from proton-conducting materials, precursors of proton-conducting materials, and combinations thereof.

In some embodiments, the method comprises:

(a) contacting said first electrode material with a first catalyst material;

(b) contacting the second electrode material with a second catalyst material; and

(c) arranging the first electrode material and the second electrode material in a spatial arrangement such that the first catalyst material and the second catalyst material face each other and form a space between the first catalyst material and the second catalyst material. electrode material.

Additionally, in some embodiments, at least one of the first catalyst material and the second catalyst material comprises a processable catalyst ink composition. In some embodiments, the method further comprises applying the treatable catalyst ink composition to a proton exchange membrane. In some embodiments, the method includes applying the treatable catalyst ink composition onto at least one of the first and second electrode materials. In some embodiments, the method includes applying the treatable catalyst ink composition to the proton exchange membrane and at least one of the first and second electrode materials.

In some embodiments, the chemical vapor deposition (CVD) method, electrospray method, electric field desorption method, radio frequency plasma enhanced CVD method, flame spray deposition method, inkjet printing method or pulse A method in the laser desorption method applies the treatable catalyst ink composition.

In some embodiments, the electrode material is selected from carbon cloth, carbon paper, and carbon black. In some embodiments, the electrode material comprises a patterned electrode material.

Accordingly, in some embodiments, the present invention provides a membrane electrode assembly (MEA) prepared by the methods described herein.

In some embodiments, treating an electrode material, such as carbon cloth, carbon paper, and/or carbon black, increases its surface area, thereby increasing the power density of an electrochemical cell in which the electrode material is operatively disposed. Referring now to FIG. 16, an electrode material 1600 is provided. Electrode material 1600 may be patterned using conventional photolithographic techniques (not shown), forming patterned electrode material 1602, or may be patterned directly using an electron beam, such as etchant EA of FIG. 16 . In some embodiments, the electrode material 1600 may further include a photoresist 1604, eg, for e-beam lithography. In some embodiments, a mask 1606 may be provided, eg, for plasma etching (eg, oxygen reactive ion etching).

Accordingly, in some embodiments, the electrode material is patterned by a process selected from the group consisting of, but not limited to:

(a) photolithography process;

(b) electron beam direct writing process (direct electron beam process);

(c) an electron beam lithography process using a photoresist; and

(d) Plasma etching process using a mask.

In some embodiments, the plasma etching method includes an oxygen reactive ion etching method.

V. Methods of Forming Electrochemical Cells

In some embodiments, the present invention provides methods of forming electrochemical cells, such as fuel cells. Referring now to FIG. 17A, a proton exchange membrane 1700 is provided. The proton exchange membrane 1700 can be prepared from the liquid precursor materials of the invention by the methods described herein. Proton exchange membrane 1700 is operatively disposed between and in contact with first catalyst material 1702 and second catalyst material 1704 . In some embodiments, first catalyst material 1702 and second catalyst material 1704 independently of each other comprise a metal selected from the group consisting of platinum, ruthenium, molybdenum, chromium, and combinations thereof.

With continued reference to FIG. 17A , first catalyst material 1702 is in operable contact with first electrode material 1706 . In some embodiments, the first electrode material 1706 includes a first surface 1706a and a second surface 1706b. Thus, in some embodiments, at least one of the first surface 1706a and the second surface 1706b is in operative contact with the first catalyst material 1702 . In some embodiments, at least one of the first surface 1706a and the second surface 1706b is coated with the first catalyst material 1702 . In some embodiments, at least one of the first surface 1706a and the second surface 1706b is impregnated with the first catalyst material 1702 .

With continued reference to FIG. 17A , second catalyst material 1704 is in operative contact with second electrode material 1708 . In some embodiments, the second electrode material 1708 has a first surface 1708a and a second surface 1708b. Thus, in some embodiments, at least one of the first surface 1708a and the second surface 1708b is in operative contact with the second catalyst material 1704 . In some embodiments, at least one of the first surface 1708a and the second surface 1708b is coated with the second catalyst material 1704 . In some embodiments, at least one of the first surface 1708a and the second surface 1708b is impregnated with the second catalyst material 1704 .

Continuing with FIG. 17A , membrane electrode assembly 1710 is thus formed by operatively disposing proton exchange membrane 1700 , first catalyst layer 1702 , first electrode material 1706 , second catalyst layer 1704 , and second electrode material 1708 . Membrane electrode assembly 1710 may be operably positioned in an electrochemical cell, such as a fuel cell.

With continued reference to FIG. 17A , a first outer layer 1712 and a second outer layer 1714 are provided. In some embodiments, first outer layer 1712 and second outer layer 1714 are composed of a perfluoropolyether (PFPE) material as described herein. The first outer layer 1712 may further include a plurality of microchannels 1716 through which fuel _F1 may be introduced, and the second outer layer 1714 may further include a plurality of microchannels 1718 through which fuel F may be introduced. ₂ .

In some embodiments, first electrode material 1706 includes an anode and is in fluid communication with fuel F ₁ , which in some embodiments comprises anode fuel. In some embodiments, the anode fuel (eg, fuel F ₁ ) is selected from H ₂ , alkanes, alkyl alcohols, dialkyl ethers, and glycols. In some embodiments, the alkane is selected from methane, ethane, propane, and butane. In some embodiments, the alkyl alcohol is selected from methanol, ethanol, propanol, butanol, pentanol, and hexanol. In some embodiments, the alkyl alcohol comprises methanol. In some embodiments, the dialkyl ether includes dimethyl ether. In some embodiments, the diol includes ethylene glycol.

In some embodiments, the second electrode material 1708 comprises a cathode and is in fluid communication with fuel _F2 , which in some embodiments comprises cathode fuel. In some embodiments, the cathode fuel (eg, fuel F ₂ ) includes an oxygen (O ₂ )-containing gas, such as air. In some embodiments, the cathode fuel includes an air/water mixture.

In some embodiments, the electrochemical cell includes at least one electrical output connection E ₀ .

Referring now to FIG. 17B , in some embodiments, the plurality of microfluidics 1716 includes at least one inlet 1720 . In some embodiments, the inlet 1720 is in fluid communication with a fuel source 1722 . In some embodiments, fuel source 1722 includes fuel F ₁ . In some embodiments, fuel _F1 is selected from an anode fuel and a cathode fuel.

With continued reference to FIG. 17B , in some embodiments, the plurality of microfluidic channels 1718 includes at least one inlet 1724 . In some embodiments, the inlet 1724 is in fluid communication with a fuel source 1726 . In some embodiments, fuel source 1726 includes fuel _F2 . In some embodiments, the fuel _F2 is selected from an anode fuel and a cathode fuel.

In some embodiments, the plurality of microfluidics 1716 includes at least one outlet 1728 . In some embodiments, outlet 1728 is in fluid communication with fuel recirculation passage 1730 . In some embodiments, the outlet 1728 is in fluid communication with a waste exhaust port 1732.

In some embodiments, the plurality of microfluidics 1718 includes an outlet 1734 . In some embodiments, outlet 1734 is in fluid communication with fuel recirculation passage 1736 . In some embodiments, outlet 1734 is in fluid communication with waste outlet 1738 .

In some embodiments, the plurality of microfluidics 1716 includes a plurality of valves, such as 1740a, 1740b, and 1740c. In some embodiments, the plurality of valves 1740a, 1740b, and 1740c includes pressure-opened valves (not shown). In some embodiments, the plurality of microfluidics 1718 includes a plurality of valves, such as 1742a, 1742b, and 1742c. In some embodiments, the plurality of valves 1742a, 1742b, and 1742c includes pressure-opened valves (not shown).

In some embodiments, the plurality of microfluidics 1716 and the plurality of microfluidics 1718 each comprise a network of microfluidics (not shown).

In some embodiments, microfluidic devices are fabricated by soft lithographic methods. The term "soft lithography" as used herein refers to a method of transferring micro- and nanoscale features onto substrates by using elastomeric stamps. Soft lithography has emerged as an alternative to traditional photolithographic methods to fabricate feature sizes smaller than about 100 nm. The term "soft lithography" as used herein encompasses several methods including, but not limited to, imprint lithography (IL), replication molding, microcontact printing (MCP), capillary micromolding (MIMIC), and solvent-assisted microlithography. molding (SAMIM).

Reference is now made to Figures 18A-18C, which show schematic representations of embodiments of the present method for forming a perfluoropolyether (PFPE) layer comprising a plurality of microfluidic channels. A substrate 1800 having a patterned surface 1802 comprising raised protrusions 1804 is depicted. Thus, the patterned surface 1802 of the substrate 1800 includes at least one protrusion 1804 forming a patterned shape. In some embodiments, patterned surface 1802 of substrate 1800 includes a plurality of protrusions 1804 forming a complex pattern.

As best seen in FIG. 18B , polymer precursor 1806 is disposed on patterned surface 1802 of substrate 1800 . The polymer precursor 1806 may comprise perfluoropolyether. As shown in FIG. 18B , the polymer precursor 1806 is treated by a treatment process T _r , such as irradiating with ultraviolet light, to form a photocured perfluoropolyether patterned layer 1808 as shown in FIG. 18C .

As shown in FIG. 18C , photocured perfluoropolyether patterned layer 1808 includes recesses 1810 formed at the bottom of patterned layer 1808 . The size of the recesses 1810 corresponds to the size of the protrusions 1804 of the patterned surface 1802 of the substrate 1800 . In some embodiments, the recess 1810 includes at least one channel 1812, which in some embodiments of the invention includes a microscale channel. Patterned layer 1808 is removed from patterned surface 1802 of substrate 1800 resulting in microfluidic device 1814 . Thus, in some embodiments, soft lithography methods include contacting a liquid precursor material with a patterned substrate (eg, a silicon wafer). In some embodiments, the method further comprises processing the liquid precursor material to form a crosslinked polymer. In some embodiments, the treatment process is selected from a curing process, a chemical modification process, a network forming process, and combinations thereof.

In some embodiments, the method further includes removing the cross-linked polymer from the substrate, thereby creating a "stamp" of the desired pattern.

Poly(dimethylsiloxane) (PDMS) elastomeric materials are typically used in such microfluidic devices. However, the swelling of PDMS materials has limited its application in direct methanol fuel cells and fuel cells containing other organic liquids due to the destruction of micron-scale features. Furthermore, PDMS materials are also typically not stable to acids and bases.

The present invention solves the above-mentioned problems with PDMS elastomers in whole or in part by using a photocured PFPE material. In some embodiments, PFPE materials include fluorinated, functionalized PFPE materials, which in some embodiments have a liquid-like viscosity and can be cured into durable elastomers that exhibit the chemical resistance typical of fluoropolymers .

Thus, in some embodiments, the present invention includes cured PFPE-based materials. In some embodiments, the curing method includes a free radical curing method. In some embodiments, the free radical curing method further includes adding other monomers and macromers to the PFPE resin. Physical properties including, but not limited to, modulus, flexural strength, wetting characteristics, permeability, adhesion, and reactivity can be tuned by adding other monomers and macromers to PFPE resins.

VI. Methods of Operating Electrochemical Cells

The invention also provides methods of operating electrochemical cells, such as fuel cells. In some embodiments, the method includes:

(a) providing an electrochemical cell comprising at least one layer of perfluoropolyether (PFPE) material comprising at least one microfluidic channel;

(b) distributing the first electrode reactant and the second electrode reactant into the electrochemical cell; and

(c) producing an electrical output from said electrochemical cell.

In some embodiments, the proton exchange membrane of an electrochemical cell includes a polymer electrolyte prepared from a liquid precursor material as described herein.

In some embodiments, the first electrode reactant is selected from _H2 , alkanes, alkyl alcohols, dialkyl ethers, and glycols. In some embodiments, the alkane is selected from methane, ethane, propane, and butane. In some embodiments, the alkyl alcohol is selected from methanol, ethanol, propanol, butanol, pentanol, and hexanol. In some embodiments, the alkyl alcohol includes methanol. In some embodiments, the dialkyl ether includes dimethyl ether. In some embodiments, the diol includes ethylene glycol. In some embodiments, the second electrode reactant includes an oxygen (O ₂ )-containing gas, such as air, and in some embodiments, an air/water mixture.

In some embodiments, the method includes extracting an electrical output produced by the electrochemical cell. In some embodiments, the electrical output ranges from about 100 milliwatts to about 20 watts.

In some embodiments, the method of operating an electrochemical cell further includes supplying power to the device. In some embodiments, the device comprises a stationary device. In some embodiments, the static equipment includes a generator. In some embodiments, the device includes a portable device. In some embodiments, the portable device is selected from the group consisting of portable generators, portable instruments, power tools, electronic equipment, road or traffic signs, backup power sources, and personal vehicles. In some embodiments, the electronic device is selected from consumer electronics and military electronics. In some embodiments, the device includes automotive equipment.

Example

In order to guide those of ordinary skill in the art in the practice of representative embodiments of the invention, the following examples are given. From the present disclosure and the ordinary skill level in the art, those skilled in the art can understand that the following embodiments are only illustrative and that numerous changes, modifications and changes can be employed without departing from the scope of the present invention.

Example 1

Synthesis of Crosslinkable PFPE Liquid Precursor

Example 1.1 Synthesis of a crosslinkable PFPE liquid precursor with styrene linkages

Styrene linkages were added to both chain ends of poly(tetrafluoroethylene-co-difluoroethylene oxide) alpha, omega diol (ZDOL) (PFPE, average Mn about 3800 g/mol) by interfacial reactions. In a typical synthesis, PFPE (20 g, 5.26 mmol), solcane (10 mL) and tetrabutylammonium bisulfate (1.0 g, 2.95 mmol) were added to a round bottom flask. KOH (10 g, 0.18 mol) was dissolved in deionized water (20 mL), and the aqueous KOH solution was added to the round bottom flask. After addition of 4-vinylbenzyl chloride (2 mL, 2.8 mmol), the reaction mixture was stirred vigorously at 45°C for 48 hours. The resulting brown solid was removed by passing the product through a 0.22 micron filter. Then, the solution was extracted three times with deionized water and stirred with carbon black for 1 hour to remove any impurities. The mixture was passed through a 0.22 micron filter to remove carbon black and dried under vacuum at room temperature to remove solvent. The resulting product (S-PFPE) was a clear viscous liquid.

Synthesis and photocuring of embodiment 1.2 functional PFPE

Route 1 provides a representative route for the synthesis and photocuring of functional PFPEs.

Route 1. Synthesis and photocuring of functional PFPE

Example 1.3. Representative perfluoropolyethers

The perfluoropolyether of the present invention includes but is not limited to perfluoropolyether materials comprising the following skeleton structure:

和

and

Example 2

Synthesis of the cross-linked system

Example 2.1. General considerations

Strong acids and polyfunctional monomers can be polymerized free radically or via different chemical mechanisms. The multifunctional monomer can be a strong acid or can have at least two functionalities. An example of a strong acid that can be used in the crosslinking system for these electrochemical cell applications is perfluoro-2-(2-fluorosulfonylethoxy)propyl vinyl ether (PSEPVE). Other superacids that can be used as strong acids or polyfunctional monomers are sulfamoyl-based compounds.

In a round bottom flask under argon, mix the strong acid and polyfunctional monomer, using fluorinated or perfluorinated solvents as needed. The ratio of the two components varies according to the desired crosslink density and equivalent weight. Reaction conditions such as temperature and reaction time can be varied depending on the specific components and ease of mixing.

The liquid precursor comprising the reaction mixture is poured onto a glass sheet or patterned substrate such as a mold. Use standard steel spacers to control film thickness. The liquid precursor is chemically crosslinked by irradiation with UV light or thermally under a nitrogen flush. The mechanism of chemical crosslinking depends on the initiator used. Once the cross-linked network is prepared, base and acid hydrolysis is used to convert any remaining conducting sites to acid for increased proton conduction.

Example 2.2. Multifunctional monomers such as fluorodivinyl ethers

The nonconducting bifunctional monomers produce mechanically stable proton-conducting networks when reacted with strong acids. Commercially available compounds with a functionality greater than or equal to 2, such as 4,4'-bis(4-trifluoroethyleneoxy)biphenyl (compound 1 ), are reacted with a strong acid such as PSEPVE. In the liquid precursor state, the reaction mixture takes the shape of the surface/mold and polymerizes free-radically, thermally or photochemically in an inert atmosphere upon addition of an initiator.

Compound 1. Fluorodivinyl ether

Example 2.3. Multifunctional monomers such as tris(trifluoroethylene)benzene

Liquid precursors are patternable if the cross-linking mechanism is feasible. Free radical curing of trifunctional monomers provides a chemically crosslinked network available for proton conduction when cured with strong acids. An example of a trifunctional monomer is tris(α,β,β-trifluoroethylene)benzene (compound 2), prepared using 1,3,5-tribromobenzene (see Scheme 2). The starting material in Scheme 2 can also represent a trifunctional monomer for subsequent crosslinking with a strong acid. An example of a strong acid is PSEPVE. The reaction mixture in the liquid precursor state can be crosslinked in the manner described in Example 2.2.

Compound 2. Trifluoroethylene benzene

Example 2.4. Multifunctional monomers such as fluorodivinyl ether sulfimide

Reaction of a bifunctional macromer (also a superacid) with another strong acid (such as PSEPVE) results in a highly conductive, mechanically stable network. In liquid precursor form, the reactant assumes the shape of any mold prior to crosslinking. Subsequent crosslinking produces a high surface area, highly conductive membrane. An example of a superacid useful as a difunctional macromer is bis(PSEPVE-yl)sulfonamide (compound 3), prepared by means of sulfonamide chemistry (see Schemes 3 and 4). The reaction mixture can be cured under the conditions described in Example 2.2.

Compound 3. Fluorodivinylsulfonamide

Example 2.5. Polyfunctional monomers such as fluorodivinyl ether disulfimide

Divinyl ether diiminosulfonyl was prepared using sulfimidosulfonyl chemistry using a strong acid such as PSEPVE and disulfonyl fluoride to obtain this crosslinkable superacid monomer (compound 4, scheme 6). Disulfonyl fluorides can be prepared using diiodanes (eg α,ω-diiodoperfluoroalkanes) (Scheme 5). Divinyl ether disulfimide reacts with another strong acid such as PSEPVE to form a highly conductive membrane. The reactants can be cured under the conditions described in Example 2.2.

Compound 4. Fluorodivinyl ether diiminosulfonyl

Route 2. Conversion of tribromobenzene to tris(α,β,β-trifluoroethylene)benzene (see DesMarteau, et al., Chem. Commun., 2596-2597 (2003)).

Route 3. Preparation of PSEPVE-based silylated sulfonimides ( see DesMarteau, DD, et al., Journal of Fluorine Chemistry, 125, 1231-1240 (2004)).

Scheme 4. Preparation of PSEPVE-based sulfimides.

Scheme 5. Preparation of disulfonyl fluoride ( see DesMarteau , DD, et al., Journal of Fluorine Chemistry, 125, 1179-1185 (2004)).

Route 6. Preparation of divinyl ether diiminosulfonyl.

Example 3

Synthesis of crosslinkable terpolymers

Example 3.1. General considerations

Polymerization of terpolymers containing fluoroolefins, strong acids and low molecular weight cure site monomers (CSM). An example of a fluorine-containing olefin is tetrafluoroethylene (TFE), and as a strong acid, perfluoro-2-(2-fluorosulfonylethoxy)propyl vinyl ether (PSEPVE) is chosen. A typical polymer can be loaded at 40% solids. The solvent of choice for TFE-based polymerizations is optionally carbon dioxide (CO ₂ ). The initiator concentration adjusts the desired molecular weight. Higher concentrations of initiators will result in lower relative molecular weights, while lower concentrations of initiators will result in higher relative molecular weights. Free radical polymerization is carried out under thermal initiators. Reaction times vary according to the desired conversion. Polymerization is preferably carried out using solid site monomers commonly used in fluoroelastomer and perfluoroelastomer technology. For example, the solid site monomers may include cyanovinyl ethers, bromine-containing monomers, bromine-containing olefins, bromine-containing vinyl ethers, iodine-containing monomers, iodine-containing olefins, iodine-containing vinyl ethers, nitrile-containing Fluoroolefins, fluorinated vinyl ethers having nitrile groups, 1,1,3,3,3-pentafluoropropene, perfluoro(2-phenoxypropyl) vinyl ether and non-conjugated dienes.

The terpolymer formed by the polymerization of the fluoroolefin, strong acid and cure site monomer (CSM) can be crosslinked after polymerization and before the terpolymer is hydrolyzed. The polymerization products include gums or liquids with a Mooney viscosity of 160 or less. The terpolymer is poured under an inert atmosphere into a mold with the desired pattern or onto a glass slide. Use standard steel spacers to control film thickness between glass sheets. The terpolymer takes the shape of the patterned mold. Cure chemistry is optionally performed following fluoroelastomer and perfluoroelastomer technology. The liquid precursors are chemically crosslinked by various curing systems including heat or gamma radiation. Peroxide based or bisphenol curing systems can also be impregnated according to CSM. A chemically crosslinked film is produced with an active surface area higher than the geometric surface area of the mould. Subsequent hydrolysis (with base and acid) produces a patterned proton conducting membrane with high mechanical integrity.

Example 3.2. Terpolymers with Bromine-Containing Cure Site Monomers

For the polymerization of terpolymers comprising fluoroolefins, strong acids, and cure site monomers, bromine-containing cure site monomers are selected. Bromine-containing compounds used as cure site monomers may include vinyl bromide, 1-bromo-2,2-difluoroethylene, perfluoroallyl bromide, 4-bromo-1,1,2-trifluorobutene, 4 -Bromoperfluoro-1-butene, 4-bromo-3,3,4,4-tetrafluoro-1-butene, bromotrifluoroethylene and perfluorobromo-vinyl ether.

Example 3.3. Terpolymers with cure site monomers comprising cyanovinyl ether

For the polymerization of terpolymers comprising fluoroolefins, strong acids, and cure site monomers, select cyano vinyl ether-containing cure site monomers. Cyanovinyl ether-containing compounds useful as cure site monomers may include perfluoro(8-cyano-5-methyl-3,6-dioca-1-octene) and perfluoro(9- cyano-5-methyl-3,6-dioxo-1-octene).

Example 4

Preparation of other liquid materials

Example 4.1. Synthesis in _CO2

Route 7. Synthesis in _CO2

Example 4.2. Synthesis of poly(TFE-Nb-PSEPVE)

Route 8. Synthesis of Poly(TFE-Nb-PSEPVE)

Example 4.3. Synthesis of poly(TFE-PDD-PSEPVE)

Route 9. Synthesis of Poly(TFE-PDD-PSEPVE)

Example 4.4. Synthesis of norbornene derivatives

Route 10. Synthesis of norbornene derivatives

Example 4.5. Vinyl Alcohol-Containing PEM

Route 11. PEM with Vinyl Alcohol

Example 5

Synthesis of Proton Conducting Material Precursors

Example 5.1. Synthesis of styrene sulfonate

To a round bottom flask under Ar flow was added 4-vinylbenzenesulfonyl chloride (37.5 mmol), 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluoro - 1-octanol (37.5 mmol), triethylamine (10 mL) and pyridine (20 mL). The resulting slurry was stirred at room temperature for 20 hours (h). The reaction mixture was then quenched into triethylamine by pouring excess hydrochloric acid-ice bath. The aqueous solution was extracted three times with ether, and the combined ether layers were washed sequentially with water, 10% NaOH solution and 10% NaCl solution. The ether solution was then dried over _MgSO4 for 1 h. The _MgSO4 was filtered again and the ether was removed by evaporation in vacuo. The obtained styrene sulfonate was a yellow solid with a melting point of about 40°C.

Example 5.2. Synthesis of styrene sulfonate

To a round bottom flask under Ar flow was added 4-vinylbenzenesulfonyl chloride (37.5 mmol), 2,2,3,3,4,4,5,5,6,6,7,7,7-tridecafluoro - 1-heptanol (37.5 mmol), triethylamine (10 mL) and pyridine (20 mL). The resulting slurry was stirred at room temperature for 20 h. The reaction mixture was then quenched into triethylamine by pouring excess hydrochloric acid-ice bath. The aqueous solution was extracted three times with ether, and the combined ether layers were washed sequentially with water, 10% NaOH solution and 10% NaCl solution. The ether solution was then dried over _MgSO4 for 1 h. The _MgSO4 was filtered again and the ether was removed by evaporation in vacuo.

Example 6

Preparation of proton exchange membrane

The preparation of the proton exchange membrane of embodiment 6.1.EW1900

70% by weight of S-PFPE and 30% by weight of styrene sulfonate were mixed at room temperature. The mixture was heated above 40 °C and became a homogeneous yellow liquid. The liquid precursor was poured onto a preheated glass slide. Film thickness is controlled using standard steel spacers. The liquid precursor was chemically crosslinked by irradiation with UV light (λ = 365 nm) for 10 minutes under a nitrogen flush. The resulting film was in the form of an ester, clear and slightly yellowish.

To convert the sulfonate groups to sulfonic acids, the membrane was immersed in a mixture of 30% NaOH in water and methanol (5:6 by volume) overnight and then refluxed for 10 hours. The membrane was then rinsed with water and stirred 4 times with fresh 20% by weight HCl solution within 24 hours. The resulting film is in the acid form. Residual HCl was washed with water. The resulting PEM had an equivalent weight of 1900 g/mole. The conductivity of the PEM under fully hydrated conditions was measured by AC impedance, and the results are shown in Figure 4.

The preparation of the proton exchange membrane of embodiment 6.2.EW1250

60% by weight of S-PFPE and 40% by weight of styrene sulfonate were mixed at room temperature. The mixture was heated above 40 °C and became a homogeneous yellow liquid. The liquid precursor was poured onto a preheated glass slide. Use standard steel spacers to control film thickness. The liquid precursor was chemically crosslinked by irradiation with UV light (λ = 365 nm) for 10 minutes under a nitrogen flush. The resulting film was in the form of an ester, clear and slightly yellowish.

To convert the sulfonate groups to sulfonic acids, the membrane was immersed in a mixture of 30% NaOH in water and methanol (5:6 by volume) overnight and then refluxed for 10 hours. The membrane was then rinsed with water and stirred 4 times with fresh 20% by weight HCl solution within 24 hours. The resulting film is in the acid form. Residual HCl was washed with water. The resulting PEM had an equivalent weight of 1250 g/mole. The conductivity of the PEM under fully hydrated conditions was measured by AC impedance, and the results are shown in Figure 5.

The preparation of the proton exchange membrane of embodiment 6.3.EW850

50% by weight of S-PFPE and 50% by weight of styrene sulfonate were mixed at room temperature. The mixture was heated above 40 °C and became a homogeneous yellow liquid. The liquid precursor was poured onto a preheated glass slide. Use standard steel spacers to control film thickness. The liquid precursor was chemically crosslinked by irradiation with UV light (λ = 365 nm) for 10 minutes under a nitrogen flush. The resulting film was in the form of an ester, clear and slightly yellowish.

To convert the sulfonate groups to sulfonic acids, the membrane was immersed in a mixture of 30% NaOH in water and methanol (5:6 by volume) overnight and then refluxed for 10 hours. The membrane was then rinsed with water and stirred 4 times with fresh 20% by weight HCl solution within 24 hours. The resulting film is in the acid form. Residual HCl was washed with water. The resulting PEM had an equivalent weight of 850 g/mole. The conductivity of the PEM under fully hydrated conditions was measured by AC impedance, and the results are shown in Figure 6.

The preparation of the proton exchange membrane of embodiment 6.4.EW660

40% by weight of S-PFPE and 60% by weight of styrene sulfonate were mixed at room temperature. The mixture was heated above 40 °C and became a homogeneous yellow liquid. The liquid precursor was poured onto a preheated glass slide. Use standard steel spacers to control film thickness. The liquid precursor was chemically crosslinked by irradiation with UV light (λ = 365 nm) for 10 minutes under a nitrogen flush. The resulting film was in the form of an ester, clear and slightly yellowish.

To convert the sulfonate groups to sulfonic acids, the membrane was immersed in a mixture of 30% NaOH in water and methanol (5:6 by volume) overnight and then refluxed for 10 hours. The membrane was then rinsed with water and stirred 4 times with fresh 20% by weight HCl solution within 24 hours. The resulting film is in the acid form. Residual HCl was washed with water. The resulting PEM had an equivalent weight of 660 g/mole. The conductivity of the PEM under fully hydrated conditions was measured by AC impedance, and the results are shown in FIG. 7 .

The preparation of the proton exchange membrane of embodiment 6.5.EW550

30% by weight of S-PFPE and 70% by weight of styrene sulfonate were mixed at room temperature. The mixture was heated above 40 °C and became a homogeneous yellow liquid. The liquid precursor was poured onto a preheated glass slide. Use standard steel spacers to control film thickness. The liquid precursor was chemically crosslinked by irradiation with UV light (λ = 365 nm) for 10 minutes under a nitrogen flush. The resulting film was in the form of an ester, clear and slightly yellowish.

To convert the sulfonate groups to sulfonic acids, the membrane was immersed in a mixture of 30% NaOH in water and methanol (5:6 by volume) overnight and then refluxed for 10 hours. The membrane was then rinsed with water and stirred 4 times with fresh 20% by weight HCl solution within 24 hours. The resulting film is in the acid form. Residual HCl was washed with water. The resulting PEM had an equivalent weight of 550 g/mole. The conductivity of the PEM under fully hydrated conditions was measured by AC impedance, and the results are shown in FIG. 8 .

Example 7

Fabrication of high surface area PEMs by soft lithography Fabrication of PEM with sharkskin pattern

Mix S-PFPE and styrene sulfonate in the desired ratio. The mixture was heated above 40 °C and became a homogeneous yellow liquid. This liquid precursor was poured onto a preheated silicon wafer patterned with sharkskin. Use standard steel spacers to control film thickness. The liquid precursor was chemically crosslinked by irradiation with UV light (λ = 365 nm) for 10 minutes under a nitrogen flush. The patterned film was removed from the silicon wafer after curing. The resulting film was in the form of an ester, clear and slightly yellowish.

To convert the sulfonate groups to sulfonic acids, the membrane was immersed in a mixture of 30% NaOH in water and methanol (5:6 by volume) overnight and then refluxed for 10 hours. The membrane was then rinsed with water and stirred 4 times with fresh 20% by weight HCl solution within 24 hours. The resulting film is in the acid form. Residual HCl was washed with water.

Scanning electron micrographs of the PEM with shark skin pattern before and after hydrolysis are shown in Figures 2A and 2B. The characteristic dimensions of the sharkskin pattern are 2 microns wide and 8 microns high. By using the sharkskin pattern, the surface area of the patterned PEM is about five times larger than the corresponding flat PEM. As shown, high-fidelity patterns were easily obtained through the soft lithography route. After hydrolysis, the pattern swells due to water absorption, but retains the original characteristics.

Example 8

Conformal Application of Catalysts on PEMs

Example 8.1. Catalyst deposition on PEM by electrospray technique

A catalyst comprising platinum or platinum dispersed on carbon was deposited onto a three-dimensional PEM with a sharkskin pattern by electrospray technique. Figures 12A and 12B show scanning electron micrographs of a catalyst-deposited PEM.

Example 8.2. Catalyst deposition on PEM by vapor deposition technique

Platinum catalyst was deposited onto the 3D PEM with sharkskin pattern by vapor deposition technique. Figure 13 shows a scanning electron micrograph of a catalyst-deposited PEM.

Example 9

Preparation of 3D MEA

Example 9.1.

The liquid precursor approach also provides three-dimensional membrane electrode assemblies (MEAs) and fuel cell stacks. 14A and 14B show schematic diagrams of MEA structures based on three-dimensional membranes and two-dimensional electrodes with conformal or non-conformal loading of catalysts.

Example 9.2.

The liquid precursor approach also offers three-dimensional (3-D) membrane electrode assemblies (MEAs) and fuel cell stacks. Figure 15 shows a schematic diagram of a MEA structure based on a three-dimensional membrane and three-dimensional electrodes conformally loaded with a catalyst.

It is understood that many details of the invention may be changed without departing from the scope of the invention. In addition, the foregoing descriptions are for illustration only, and are not intended to limit the present invention.

Claims (64)

1. A method for preparing a polymer electrolyte, the method comprising: (a) providing a 100% cured liquid precursor material, wherein the 100% cured liquid precursor material comprises from about 70% to about 100% by weight polymerizable material; and (b) processing the 100% cured liquid precursor material to form a polymer electrolyte. 2. The method of claim 1, wherein the 100% cured liquid precursor material comprises a material selected from the group consisting of proton conducting materials, precursors of proton conducting materials, and combinations thereof. 3. The method of claim 1, wherein the 100% cured liquid precursor material comprises a material selected from the group consisting of monomers, oligomers, macromers, ionomers, and combinations thereof. 4. The method of claim 3, wherein at least one of the monomers, oligomers, macromers, and ionomers comprises a functionalized perfluoropolyether (PFPE) material. 5. The method of claim 4, wherein the functionalized perfluoropolyether (PFPE) material comprises a backbone structure selected from the following structures: and

wherein X is present or absent, and when X is present, includes a capping group, and n is an integer from 1-100. 6. The method of claim 5, wherein the functionalized PFPE material is selected from the group consisting of:

and

wherein R is selected from alkyl, substituted alkyl, aryl and substituted aryl, and wherein m and n are each independently an integer of 1-100. 7. The method of claim 3, wherein the ionomer is selected from the group consisting of sulfonic acid materials, derivatives of sulfonic acid materials, and phosphoric acid materials. 8. The method of claim 7, wherein the derivative of the sulfonic acid material comprises a material selected from the group consisting of:

and X ₂ —Ar-Y _t , in: Y is selected from _-SO2F and _-SO3H ; _R is selected from alkyl, substituted alkyl, hydroxyl, alkoxy, fluorine-containing alkenyl, cyano and nitro; X ₁ is selected from the group consisting of bond, O, S, SO, SO ₂ , CO, NR ₂ and R ₃ ; X ₂ is selected from O, S and NR ₂ , in: R _is selected from hydrogen, alkyl, substituted alkyl, aryl, and substituted aryl; and _R is selected from alkylene, substituted alkylene, aryl and substituted aryl; Ar is selected from aryl and substituted aryl; B is 1,2-perfluorocyclobutylene; t is an integer of 1-3; m is an integer from 0 to 1000; p is an integer from 1 to 1000; and q is an integer of 1-5. 9. The method of claim 1, wherein the processing of the 100% cured liquid precursor material comprises a process selected from the group consisting of: (a) a curing process, wherein the curing process comprises a process selected from a thermal process, a photochemical process, and an irradiation process, and wherein the irradiation process comprises irradiating the liquid precursor with a ray selected from gamma rays and electron beams; (b) chemical modification process, wherein said chemical modification process comprises cross-linking process; (c) the process of forming the network; and (d) Combinations of the above procedures. 10. A polymer electrolyte comprising 100% cured liquid precursor material, wherein the 100% cured liquid precursor material comprises from about 70% to about 100% by weight polymerizable material. 11. The polymer electrolyte of claim 10, wherein the polymer electrolyte has an equivalent weight, and wherein the equivalent weight is selected from the group consisting of an equivalent weight less than about 1500 and greater than about 1000, an equivalent weight less than about 1000 and greater than about 800, In the equivalent weight of less than about 800 and greater than about 500 and in the equivalent weight of less than about 500. 12. An electrochemical cell comprising the polymer electrolyte of claim 10. 13. A method of preparing a patterned polymer electrolyte, the method comprising: (a) contacting a liquid precursor material with a patterned substrate, wherein the patterned substrate has a predetermined geometry and macroscopic surface area; and (b) processing the liquid precursor material to form a patterned polymer electrolyte. 14. The method of claim 13, wherein the liquid precursor material comprises a material selected from the group consisting of proton conducting materials, precursors of proton conducting materials, and combinations thereof. 15. The method of claim 13, wherein said predetermined geometry comprises a non-planar geometry having a dimension selected from the group consisting of a dimension less than about 10 millimeters and greater than about 1 millimeter, a dimension less than about 1 millimeter and greater than about 100 microns, Among sizes less than about 100 microns and greater than about 10 microns, sizes less than about 10 microns and greater than about 1 micron, and sizes less than about 1 micron. 16. The method of claim 13, wherein the predetermined geometry is defined by one of a catalyst layer and an electrode material comprising a membrane electrode assembly. 17. The method of claim 13, wherein the predetermined geometry comprises a structure selected from the group consisting of patterns, pegs, walls, intersecting surfaces, and curled cylinders. 18. The method of claim 13, wherein said predetermined geometric shape comprises structures having a surface area greater than the macroscopic surface area of said patterned substrate. 19. The method of claim 13, wherein the processing of the liquid precursor material comprises a process selected from the group consisting of: (a) curing process; (b) chemical modification process; (c) the process of forming a network; (d) solvent evaporation process; and (e) A combination of the above procedures. 20. A patterned proton exchange membrane prepared by the method of claim 13. 21. An electrochemical cell comprising the patterned proton exchange membrane of claim 20. 22. A method of preparing a polymer electrolyte having a plurality of equivalent weights, the method comprising: (a) applying to the substrate a first liquid precursor material having a first equivalent weight; (b) treating said first liquid precursor material to form a first layer of treated liquid precursor material on the substrate; (c) applying a second liquid precursor material having a second equivalent weight to the first layer of treated liquid precursor material on the substrate; and (d) treating the second liquid precursor material to form a polymer electrolyte having a plurality of equivalent weights. 23. The method of claim 22, wherein the first liquid precursor material, the second liquid precursor material are selected from the group consisting of proton conducting materials, precursors of proton conducting materials, and combinations thereof. 24. The method of claim 22, wherein said first equivalent weight is greater than said second equivalent weight. 25. The method of claim 22, wherein said substrate is selected from the group consisting of an anode and a cathode. 26. The method of claim 22, comprising repeating steps (c) to (d) with a predetermined plurality of liquid precursor materials having a plurality of equivalent weights to form a polymer electrolyte having a plurality of equivalent weights, wherein the plurality of The liquid precursor material is selected from the group consisting of proton-conducting materials, precursors of proton-conducting materials, and combinations thereof. 27. A polymer electrolyte having multiple equivalent weights prepared by the method of claim 22. 28. An electrochemical cell comprising the polymer electrolyte of claim 27. 29. A method of forming a membrane electrode assembly (MEA), the method comprising: (a) providing a patterned proton exchange membrane; (b) providing a first catalyst material and a second catalyst material; (c) providing a first electrode material and a second electrode material; (d) operatively disposing said proton exchange membrane, said first and second catalyst materials, and said first and second electrode materials in conductive communication to form a membrane electrode assembly. 30. The method of claim 29, wherein at least one of the first catalyst material and the second catalyst material comprises a disposable catalyst ink composition. 31. The method of claim 30, wherein the processable catalyst ink composition comprises a mixture of a liquid precursor material and a catalyst. 32. The method of claim 31, wherein the liquid precursor material comprises a liquid perfluoropolyether material having chemically stable end groups. 33. The method of claim 31, wherein the catalyst comprises a metal selected from the group consisting of platinum, ruthenium, molybdenum, chromium, and combinations thereof. 34. The method of claim 30, wherein the processable catalyst ink composition comprises carbon black. 35. The method of claim 30, comprising applying the treatable catalyst ink composition to at least one of the proton exchange membrane and the first and second electrode materials. 36. The method of claim 35, comprising conformally applying the treatable catalyst ink composition to at least one of the proton exchange membrane and the first and second electrode materials. 37. The method of claim 35, wherein the application of the treatable catalyst ink composition comprises a method selected from the group consisting of chemical vapor deposition (CVD) methods, electrospray methods, electric field desorption methods, radio frequency plasma enhanced CVD method, flame spray deposition method, inkjet printing method and pulsed laser desorption method. 38. The method of claim 29, wherein the electrode material is selected from the group consisting of carbon cloth, carbon paper, and carbon black. 39. The method of claim 38, comprising patterning of electrode material, wherein said patterning of electrode material comprises a process selected from the group consisting of: (a) photolithography process; (b) Electron beam direct writing process; (c) electron beam lithography process using photoresists; and (d) Plasma etching process using a mask. 40. A membrane electrode assembly (MEA) formed by the method of claim 29. 41. A method of making a membrane electrode assembly, the method comprising: (a) providing a first electrode material; (b) providing a second electrode material; (c) disposing said first electrode material and second electrode material in a spatial arrangement forming a gap between said first electrode material and second electrode material; (d) disposing a liquid precursor material in the space between said first electrode material and second electrode material; and (e) processing the liquid precursor material to form a membrane electrode assembly. 42. The method of claim 41, wherein the liquid precursor material is selected from the group consisting of proton conducting materials, precursors of proton conducting materials, and combinations thereof. 43. A membrane electrode assembly (MEA) formed by the method of claim 41. 44. A method of forming an electrochemical cell, the method comprising: (a) providing at least one layer of perfluoropolyether (PFPE) material comprising at least one microfluidic channel; (b) providing a first electrode material and a second electrode material; (c) providing a first catalyst material and a second catalyst material; (d) provision of proton exchange membranes; and (e) operatively disposing said at least one layer of PFPE material, said first electrode material, said second electrode material, said first catalyst material, said second catalyst material, and said proton exchange membrane, whereby An electrochemical cell is formed. 45. The method of claim 44, comprising providing: (a) a first layer of photocured perfluoropolyether (PFPE) comprising at least one first microchannel in fluid communication with said first electrode; and (b) a second layer of photocured perfluoropolyether (PFPE) comprising at least one second microfluidic channel in fluid communication with said second electrode. 46. The method of claim 44, wherein said at least one microfluidic channel has an inlet. 47. The method of claim 46, wherein the inlet is in fluid communication with a fuel source. 48. The method of claim 47, wherein the fuel source comprises methanol. 49. The method of claim 47, wherein the fuel source comprises an oxygen ( _O2 ) containing gas. 50. The method of claim 44, wherein said at least one microfluidic channel has an outlet. 51. The method of claim 50, wherein the outlet is in fluid communication with at least one of a fuel recirculation passage and a waste discharge. 52. The method of claim 44, wherein said at least one microfluidic channel comprises a valve. 53. The method of claim 44, comprising a microfluidic network. 54. The method of claim 44, wherein at least one of the first electrode material and the second electrode material is selected from the group consisting of carbon cloth, carbon paper, and carbon black. 55. The method of claim 44, wherein said first electrode material: (a) coating with said first catalyst material; (b) impregnated with said first catalyst material; or (c) A combination of the above. 56. The method of claim 44, wherein said second electrode material: (a) coating with said second catalyst material; (b) impregnated with said second catalyst material; or (c) A combination of the above. 57. The method of claim 44, wherein at least one of the first catalyst material and the second catalyst material comprises a metal selected from the group consisting of platinum, ruthenium, molybdenum, chromium, and combinations thereof. 58. The method of claim 44, wherein said proton exchange membrane comprises a liquid precursor material selected from the group consisting of: (a) derivatives of sulfonic acid materials; (b) Perfluoropolyether (PFPE) materials; and (c) Combinations of them. 59. The method of claim 44, comprising operatively connecting at least one electrical output connection to at least one of said first and second electrode materials. 60. An electrochemical cell formed by the method of claim 44. 61. A method of operating an electrochemical cell, the method comprising: (a) providing an electrochemical cell comprising at least one layer of perfluoropolyether (PFPE) material, said layer of perfluoropolyether material comprising at least one microfluidic channel; (b) distributing the first electrode reactant and the second electrode reactant into the electrochemical cell; and (c) producing an electrical output from said electrochemical cell. 62. The method of claim 61, wherein the first electrode reactant is selected from the group consisting of _H2 , alkanes, alkyl alcohols, dialkyl ethers, and glycols. 63. The method of claim 61, wherein the second electrode reactant is selected from an oxygen ( _O2 ) containing gas. 64. The method of claim 61, comprising directing the electrical output of said electrochemical cell to provide power to a device, wherein said device is selected from the group consisting of generators, portable instruments, power tools, road signs, backup power supplies, consumer electronics , military electronic equipment, automotive equipment, and non-automotive personal vehicles.

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