HK1171006B - Carbon nanotube composite structures and methods of manufacturing the same - Google Patents

Description

Carbon nanotube composite structure and method for producing same

Cross Reference to Related Applications

This application claims priority from the following provisional applications filed earlier: SEQUENCE number 61/223,338, filed on 7/6/2009 under THE name of Electrode STRUCTURE FOR ELECTRICAL POWER DEVICE AND PROCESS SEQUENCE FOR RPREPARING THE STRUCTURE; 61/241,241, filed on 9, 10, 2009 under the name of ANODE STRUCTURE FOR AN ELECTROCHEMICAL POWER DEVICE DEVICEAND PROCESSS SEQUENCE FOR PREPARING THE STRUCTURE; 61/259,365, filed 11/9/2009 under the name COMPOSITE ELECTRODESTRUCTURE FOR ANODE FOR BATTERIES AND PROCESSS SEQUENCEFOR MAKING THE STRUCTURE; 61/310,563, filed 3/4/2010 under the name OF METHOD TO manual SHEET OF METAL-CARBON NAOTUBECOMPOSITE; 61/347,995, filed 5/25/2010 under the name OF METHOD and program short OF METAL-CARBON nano tube COMPOSITE, which is incorporated herein by reference in its entirety and for all purposes.

Background

The field is as follows:

the present invention relates generally to structures and devices comprising an array of anchored Carbon Nanotubes (CNTs) protruding from a conductive composite for use as all or part of an electrical current conductor and an electrode for an electrochemical power device such as a battery, supercapacitor, fuel cell, or the like. In addition, the present invention also relates generally to methods of making the above structures and devices.

The related technology comprises the following steps:

the electrochemical power plant described herein generally includes the following devices, which may: electrical energy is stored in chemical form and released again as needed in electrical form (e.g., Li-ion batteries for mobile phones; chemical energy is converted to electrical energy (e.g., fuel cells that can use chemical fuels such as hydrogen or methanol and convert it to electrical energy), and/or electrical energy is stored and released as needed (e.g., supercapacitors).

Although the mechanisms of energy storage and conversion may differ among these devices, one common aspect of all of these devices is the need for current conductors and/or electrodes. Each device typically has two electrodes, an anode through which current flows into the device, and a cathode through which current flows out of the device. Sometimes, a current collector (typically a metal such as copper or aluminum) is used in addition to or as part of the electrode to improve electrical conduction.

Carbon Nanotubes (CNTs) are generally known to have excellent electrical conductivity, thermal conductivity, mechanical strength and chemical resistance. While CNTs have been noted more than half a century ago, the recent prediction of the remarkable physical properties of CNTs has stimulated widespread interest in this material, CNTs have been touted as a new material in the 21 st century. CNTs have been extensively studied and several organizations have proposed potential applications of this material in composites for higher strength and thermal conductivity, for biomedical applications such as nanoprobes and nanopipettes for targeted drug delivery, field emission devices such as light emitting diodes, energy generation devices such as solar cells, nanoscale probes, nanoscale semiconductor device applications, electrodes for electrochemical energy devices such as batteries, fuel cells, supercapacitors, and the like.

In the field of electrochemical energy devices, for example, CNT-based structures have been suggested as potential candidates for electrodes for batteries, fuel cells and supercapacitors. In particular, in the field of lithium ion batteries, there are various examples of using CNTs for electrodes. U.S. Pat. No. 6,709,471 discloses a CNT-boron nitride battery comprising a structure using the walls of the CNTs as electrodes and boron nitride as an intermediate dielectric layer. Also, us patent No. 5,879,836 describes the use of carbon fibrils as lithium intercalation sites in an electrode. Another example includes us patent No. 7,442,284, which describes the use of CNT arrays coated with conductive polymers as electrodes for a variety of devices, including energy storage devices.

In the field of fuel cells, U.S. patent No. 7,585,584 describes the use of CNTs grown on a carbon substrate with catalyst particles deposited on the CNTs. Also, in the field of supercapacitors, U.S. Pat. nos.6,665,169 and 6,205,016 describe the use of carbon nanofibers as electrodes to increase performance.

In addition to CNTs, CNT-based composites (which typically include conductive Materials embedded with CNTs) have been investigated in an attempt to take advantage of many of the desirable properties of CNTs (see, e.g., "Carbon nanotube composites", authors: Harris P.J.F. International Materials Reviews, Volume 49, Number 1, February 2004, pp.31-43 (13)). Various CNT-based composites and various techniques are known. For example, CNT-polymer composites are typically prepared by: pretreated CNTs dispersed in a solution comprising a polymer are dissolved and evaporation of the solvent is controlled (see, e.g., m.s.p.shamfer and a.h.window: adv. mater, 1999, 11, 937-: hot-drawn CNTs and Metal powders (see, for example, t. kuzumaki, k. miyazawa, h. ichino and k. ito: j. mater. res., 1998, 13, 2445-. All documents cited herein are incorporated by reference herein in their entirety.

Disclosure of Invention

According to one aspect of the invention, a structure for an electrochemical power device is provided. In one example, a structure includes a conductive composite layer and an array of carbon nanotubes anchored therein such that at least a portion of the carbon nanotubes protrude from the composite conductive layer. The structure may further include nano-scale particles or a thin film disposed on the carbon nanotubes. The exemplary structure can be used as an electrode in a variety of electrochemical power devices, such as a battery, a fuel cell, or a capacitor.

The portions of the carbon nanotubes that extend from the composite layer may be aligned in a common direction, more (less) aligned than the portions anchored in the composite layer, or entangled. In some examples, the carbon nanotubes may protrude from both sides of the composite layer. Also, the portions of the carbon nanotubes anchored in the composite layer may be tangled or aligned. In some examples, the conductive composite layer comprises a carbon-metal composite.

According to another aspect of the present invention, an exemplary method of forming a structure for an electrochemical power device is provided. In one example, the method includes forming or disposing an array of carbon nanotubes embedded or anchored in a conductive composite layer, wherein at least a first portion of a length of the array of carbon nanotubes protrudes from the conductive composite layer. In some examples, the first portions of the carbon nanotubes are further aligned along a common direction.

The carbon nanotube array may be formed at least partially aligned according to a deposition method, an electroplating method, a template, and the like. In one example, the structure is formed by passing a substrate through an electrochemical bath having carbon nanotubes in solution, and electroplating a conductive layer having carbon nanotubes to the substrate. Magnetic and/or electric fields may be used during the formation of the conductive composite layer to assist in carbon nanotube alignment. Also, an exemplary method of forming the structure may be part of a roll-to-roll manufacturing method.

Brief Description of Drawings

Fig. 1 illustrates an example electrochemical power plant that may include one or more of the example structures described herein.

Fig. 2A and 2B show different embodiments of current conductor structures of an electrochemical power plant.

Fig. 3 shows another exemplary embodiment of a current conductor structure of an electrochemical power plant.

Fig. 4 shows another exemplary embodiment of a current conductor structure of an electrochemical power plant.

Fig. 5 shows another exemplary embodiment of a current conductor structure of an electrochemical power plant.

Fig. 6A-6E illustrate an exemplary method of forming a structure for an electrochemical power device.

Fig. 7A-7D illustrate another exemplary method of forming a structure for an electrochemical power device.

Fig. 8A-8F illustrate another exemplary method of forming a structure for an electrochemical power device.

Fig. 9 illustrates an exemplary roll-to-roll process of forming a structure of an electrochemical power device according to one embodiment.

Fig. 10 illustrates an exemplary roll-to-roll process of forming a structure of an electrochemical power device according to another embodiment.

Fig. 11 illustrates an exemplary roll-to-roll process of forming a structure of an electrochemical power device according to another embodiment.

Fig. 12 illustrates an exemplary Scanning Electron Microscope (SEM) image of a structure according to certain embodiments described herein.

Detailed Description

The following description is presented to enable any person skilled in the art to make and use various aspects of embodiments of the invention, and is provided in the context of a particular application and its requirements. Modifications to various embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Also, in the following description, numerals are provided for explanatory purposes. However, it will be recognized by one skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order not to obscure the description of the invention with unnecessary detail. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.

According to one aspect of the invention, broadly, a structure is described that includes Carbon Nanotubes (CNTs) anchored in a conductive composite and extending therefrom. The exemplary structure can be used as a conductor for electrochemical power devices such as batteries, capacitors, fuel cells, and the like. Also, exemplary methods of forming the structures and devices are provided. Initially, an exemplary structure is described, followed by exemplary methods and fabrication methods.

Exemplary apparatus and Structure：

Fig. 1 illustrates an example electrochemical power plant that may include one or more of the example current conductor structures described herein. In particular, fig. 1 illustrates a battery device 10, for example, a Li-ion battery, generally including a cathode 20 and an anode 28, separated by a separator 24. Cathode 20 is typically made of a metal oxide material and separator 24 is typically made of a polymer such as polyethylene, polypropylene, laminates of these polymers, and the like. In this example, anode 28 includes a CNT structure comprising CNTs 102 anchored in a conductive composite layer 110, the CNTs protruding therefrom and being in an electrolyte solution 30 such as a lithium salt or an organic solvent. Furthermore, one skilled in the art will recognize that regions of the electrolyte solution 30 and/or the anode 28 may include additional materials such as carbon or graphite powder, silicon powder or alloyed silicon powder, etc., which form the lithium ion insertion portion of the electrode.

Fig. 2A shows a first embodiment of a current conductor structure 100 of an electrochemical power plant. This exemplary structure 100 includes an aligned array of CNTs 102 anchored in a conductive composite layer 110. In this particular example, the CNTs 102 are anchored in and extend from a first side of the conductive composite 110 and are generally aligned, i.e., extend from the conductive composite 110 in a substantially parallel manner. The CNTs 102 may further protrude from a second side of the conductive composite 110, e.g., on an opposite side of the first side. The protrusion of the CNTs 102 on the second side may or may not be aligned. The CNTs 102 may further form a mesh as shown or be entangled within the conductive composite 110, providing a mechanical anchor for the CNTs 102 therein.

The conductive composite may include a variety of materials, such as conductive metals, metal alloys, conductive polymers, and the like. For example, metal alloys containing Ni, Zn, Cu, Al, Au, Ag, and/or other metals may be used.

CNTs 102 may comprise single or multi-walled structures, and may vary in height, width, and the like. Also, a catalyst or particle may be deposited on the CNTs 102. In one example, CNTs 102 may include a four-wall structure to match the atomic spacing of a single crystal silicon lattice. The CNTs 102 may be aligned during deposition, for example, by physical vapor deposition or by using a template or the like (which may include an Anodized Aluminum Oxide (AAO) template, a polymer-based template, a ceramic-based template, etc.). Exemplary methods of forming the structures of this and other embodiments will be described in more detail with reference to fig. 6A-11.

Structure 100 may be used as a component or substructure of an electrochemical power device; in particular, as current conductors for electrochemical devices. As an illustrative example, structure 100, as well as other described exemplary structures, may be used as an anode for a battery device, for example, as shown in fig. 1.

Fig. 2B shows a second embodiment of a current conductor structure 200 of an electrochemical power plant. Structure 200 is similar to that of fig. 2A, but in this example, conductive composite layer 110 completely covers one end of CNTs 102 and extends beyond the conductive composite region. Thus, the CNTs 102 extend from only one surface or side of the conductive composite 110.

Fig. 3 illustrates another exemplary embodiment of a current conductor structure 300 of an electrochemical power plant. The example current conductor and electrode structure is similar to that of fig. 2B, including an array of CNTs 102 anchored in a conductive composite layer 110; however, in this example, the CNTs 102 are not necessarily aligned with each other or in a common direction. In one example, the portion of CNTs 102 that protrude from composite layer 110 is more aligned in a direction perpendicular to composite layer 110 than the portion that is embedded or anchored in composite layer 110. In one example, the portion of CNTs 102 that protrudes from composite layer 110 is less entangled than the portion that is embedded or anchored in composite layer 110.

Fig. 4 shows another exemplary embodiment of a current conductor structure 400 of an electrochemical power plant. In this example, the structure 400 is similar to that of fig. 2A and 2B, but further includes nanoparticles 106 disposed or attached to an array of aligned CNTs 102 anchored in a conductive composite layer 110. The nanoparticles 106, used in battery devices, may form part of an electrode and serve as sites for lithium ion insertion. For use in a fuel cell, for example, the nanoparticles 106 may act as a catalyst to drive a chemical reaction.

The nanoparticles 106 may be deposited by any suitable method. In one example, the nanoparticles are deposited by electrodeposition from a chemical bath having particles dispersed in a solution. Another exemplary method includes electroplating or electroless plating nanoparticles onto the structure. Another exemplary method includes dispersing the nanoparticle powder with a solvent and a binder onto the structure and evaporating the solvent, thereby causing the particles to randomly adhere to the CNTs 102 and the conductive composite layer 110.

Fig. 5 shows another exemplary embodiment of a current conductor structure 500 of an electrochemical power plant. In this example, the structure 500 is similar to that of fig. 2A, 2B, or 4, but further includes a thin film or material 108 deposited on the CNTs 102 in the array; for example, at least on the portion of CNTs 102 that protrude from composite layer 110. For example, material 108 may act as a lithium ion insertion layer.

Material 108 may comprise silicon. In one example, material 108 includes a graded silicon carbon layer ranging from 100% C at the surface of each tube of CNTs 102 to 100% silicon at the outer surface of the layer of material 108, where the gradient can help handle stresses associated with the transition of one material to another. Material 108 may be deposited by any suitable method. In one example, material 108 is deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD) and Atomic Layer Deposition (ALD) using a precursor gas of C (e.g., CH4), a precursor gas of Si (e.g., SiH4), and an inert gas (e.g., Ar or N2).

It should be recognized that other combinations of the examples shown herein are possible and contemplated. For example, nanoparticles and/or films may be included in either instance, CNTs 102 protruding on both sides of a conductive composite layer 110 may be included in either instance, and either instance may protrude from the composite layer 110, as shown in fig. 3.

Exemplary method：

Broadly speaking, in embodiments of making the exemplary structures described herein, one exemplary method includes forming an array of CNTs anchored or embedded in a composite layer and protruding therefrom. The CNTs extending from the composite layer are at least partially aligned in a common direction. The portions of the CNT array anchored in the composite layer may be entangled or oriented in a non-aligned orientation.

Fig. 6A-6E illustrate an exemplary method of forming a structure for an electrochemical power device. The exemplary method begins in fig. 6A with a substrate 620 and a seeding layer 622 formed thereon for subsequent CNT growth (and/or template deposition), as described below. The substrate 620 may include, for example, silicon germanium dioxide, aluminum oxide, stainless steel, etc. Seeding layer 622 may include, for example, cobalt, iron, nickel, etc. The seeding layer 622 may be deposited on the base layer 622 by any number of suitable methods, including a variety of deposition methods (e.g., physical vapor deposition), electroplating, and the like. For example, a deposition may be performed by physical vapor deposition of a Ni seeding layer onto an oxidized silicon substrate to a thickness of less than 10 nm.

Template 624 is deposited on seeding layer 622 as shown in fig. 6B. In one example, a template 624 is formed on the seeding layer 622, and a plurality of holes with high aspect ratios are etched or otherwise formed therein for subsequent CNT growth. The template 624 may be formed of anodized aluminum oxide, anodized Al-Fe, anodized Ti, silicon dioxide, or the like. In one example, the template 624 has a thickness of about 50nm to 50 μm, and the pores formed therein may have a diameter of 1nm to 200nm and a separation distance of 1nm to 200nm from each other. Of course, other dimensions are possible and contemplated.

The holes of the template 624 may be formed by a variety of methods. In one example, an anodization technique may be used, wherein the block or film material forming the template 624 is anodized in a chemical bath, and a high voltage is used to etch a pattern on the template. Further, for example, photolithography followed by dry etching of the holes may be used to form the pattern.

Fig. 6C shows CNTs grown in the pores of the template 624. In particular, CNTs 630 grow from seeding layer 622, grow in the pores of template 624, and protrude therefrom. CNTs 630 grow in alignment in the pores of template 624, but once CNTs 630 grow beyond the height of template 624, CNTs 630 are generally free to grow and become tangled, as shown. In one example, CNTs 630 are grown by Plasma Enhanced Chemical Vapor Deposition (PECVD) using acetylene and ammonia at a pressure of about 1m Torr and a temperature of 450 ℃ to 850 ℃. In another example, CNTs 630 can be deposited using Atomic Layer Deposition (ALD) at a temperature of 20 ℃ to 450 ℃. CNTs 630 can be grown as single or multi-walled and vary in the number of walls along their height.

Composite layer 640 is deposited on the tangled CNTs as shown in figure 6D. In one example, the carbon-metal composite is deposited over the tangled portions of CNTs 630, above the template 624. The composite layer 640 may include a metal alloy including Ni, Zn, Cu, Al, Au, Ag, in any combination or ratio. The composite layer 640 may be deposited by Physical Vapor Deposition (PVD), electroplating, electroless plating, evaporation, and the like. Also, composite layer 640 may be deposited to a thickness of about 1nm to 20 μm, which may or may not encapsulate or exceed the height of the entangled portions of CNTs 630. The composite layer 640 may be further etched after deposition to achieve a desired thickness or surface characteristics. Also, polymers may be used to coat composite layer 640.

Composite layer 640 and CNTs 630 are separated from substrate 620, seeding layer 622, and template 624, as shown in figure 6E. For example, template 624 may be etched away, e.g., with wet or dry chemical etching, resulting in separation of the structure. In other examples, substrate 620 may be mechanically peeled off composite layer 640 and CNTs 630. Also, in some examples, the substrate 620 may be reused in a subsequent process to form another structure.

Fig. 7A-7D illustrate another exemplary method of forming a structure for an electrochemical power device. This example is similar to that of FIGS. 6A-6D; however, in this example, no template is used. The exemplary method begins in fig. 7A with a substrate 720 and a seeding layer 722 formed thereon for subsequent CNT growth.

CNTs 730 grow with their first portions aligned and their second portions misaligned or tangled, as shown in figure 7B. For example, CNTs 730 may be grown using Chemical Vapor Deposition (CVD) or Plasma Enhanced Chemical Vapor Deposition (PECVD) without the use of a template, wherein once the growth of CNTs 730 reaches a certain height, e.g., 50 μm to 500 μm, they are generally free to grow and become tangled. The tubes of CNTs 730 generally have a tendency to entangle due to surface forces, where the probability of entanglement increases with aspect ratios (height/diameter) exceeding about 100-. In PECVD, the presence of a plasma, and thus an electric field, generally maintains the alignment of the tube, but turning off the plasma while maintaining gas flow can cause growth to continue in a misaligned fashion. In one example, CNTs 730 are deposited by PECVD using acetylene and ammonia at a pressure of about 1m Torr and a temperature of 450 ℃ to 850 ℃.

As shown in fig. 7C, a composite layer 740 is then deposited over the entangled portions of CNTs 730. Composite layer 740 may be deposited by Physical Vapor Deposition (PVD), electroplating, electroless plating, evaporation, and the like. Also, composite layer 740 may include a thickness of 1nm to 20 μm, which may or may not encapsulate or exceed the height of the entangled portion of CNTs 730.

In one example, top-down deposition is used to form composite layer 740, such that the tangled structure of CNTs 730 receives the deposition of composite layer 740 and effectively blocks the aligned portions of most CNTs 730 from depositing. Of course, in some examples, some aligned portions of CNTs 730 may also be covered by a material. The deposition conditions of composite layer 740 may be controlled in an attempt to not fill beyond a certain depth, for example, using lower deposition rates and adding bias in PVD processes, and/or removing or reducing additives such as polyalkylene glycols and organosulfides in electroplating, which may reduce the tendency to fill deep into the structure.

The structure of CNTs 730 and composite layer 740 are separated from substrate 720 and seeding layer 722 as shown in figure 7D. For example, composite layer 740 and CNTs 730 may be peeled or mechanically removed from substrate 720 and seeding layer 722. In some examples, the substrate 720 can be reused in a subsequent process to form another structure.

Fig. 8A-8F illustrate another exemplary method of forming a structure for an electrochemical power device. This example is similar to that of FIGS. 7A-7D; however, in this example, the CNTs 830 are separated from the substrate 820 and the seeding layer 822, and then a composite material layer is added. The exemplary method begins in fig. 8A with a substrate 820 and a seeding layer 822 formed thereon for subsequent CNT growth.

CNTs 830 are grown such that a first portion thereof is aligned and a second portion thereof is tangled, as shown in fig. 8B. For example, CNTs 830 may be grown using Chemical Vapor Deposition (CVD), e.g., without the use of a template. Once the CNTs 830 grow to a certain height, e.g., 50 μm to 500 μm, they are generally free to grow and become tangled, depending on the particular process, as shown.

As shown in fig. 8C-8D, CNTs 830 are then separated from substrate 820 and seeding layer 822. In one example, the conductive adhesive tape 860 is pressed onto the tangled portions of the CNTs 830 and then moved to separate or peel the CNTs 830 from the substrate 820. Of course, other methods may be used to separate the CNTs 830.

As shown in fig. 8E, composite 840 is then deposited over the entangled portions of CNTs 830. Composite layer 840 may be deposited by Physical Vapor Deposition (PVD), electroplating, electroless plating, evaporation, and the like. Also, composite layer 840 may include a thickness of 1nm to 100nm, which may or may not encapsulate or exceed the height of the entangled portions of CNTs 830.

The structure is further separated from tape 860 as shown in fig. 8F. For example, the composite 840 and CNTs 830 may be exfoliated or mechanically removed from the tape 860. In other examples, tape 860 may be omitted and a metal may be deposited on the entangled portions of CNTs 830 by evaporation or spin coating on a subsequently cured liquid polymer glue layer and used in a manner similar to that shown for tape 860.

According to another exemplary embodiment of the present invention, a co-electrodeposition method of forming an exemplary structure is provided. In particular, methods of co-electrodeposition of CNTs and conductive composite layers are described in which the CNTs at least partially protrude from the conductive composite layer.

FIG. 9 illustrates a first exemplary roll-to-roll method and system for forming the exemplary structures described herein. In particular, the exemplary method begins with the winding of a substrate material. The substrate material may comprise a metal or alloy of copper, nickel, aluminum, zinc, gold, silver, stainless steel, etc., in a thickness range of 5 μm to 5 mm.

The base material is passed through an electroplating solution in which the CNTs are dispersed, for example, via passing through a cartridge at least partially immersed in the electroplating solution. The electroplating solution typically comprises a solution of a metal or metal ions deposited as a composite layer and CNTs dispersed therein (after a suitable surface treatment for decontamination, for example). The electroplating solution may include a copper plating electrolyte based on copper sulfate acidified with sulfuric acid. In one example, the bath may include a copper sulfate concentration of 0.1 to 1.0 molar and a sulfuric acid concentration of 0.2 to 4 molar. Also, the CNT content of the bath may be 1 to 50 wt% in one example. In another example, the CNT content may be 1 to 50 volume%.

Exemplary electroplating chemical bath：

CuSO4(0.1 to 1M)

H2SO4(0.2-2M)

Multi-walled CNT or carbon nanofibers (0.5-5 g/liter)

Surfactant (example Triton (TM)) 0.1% to 5% by volume solution

Stirring by magnetic stirrer at 60rpm and the solution at 25C

Plating Current 0.1 to 8A/dm2(Amps per square decimeter)

Of course, a variety of other concentrations, compositions, and/or electroplating solutions are possible and contemplated, depending on the desired composite layers and characteristics, CNT characteristics, material thickness, and the like. In addition, the plating bath may include various other additives such as chloride ions, polyethers, organic sulfides, nitrogen compounds, and the like. Other examples of electroplating with CNTs in solution, including various electroplating solution features, are described in U.S. patent No. 7,651,766 and U.S. patent publication No. 2010/0122910, both of which are incorporated herein by reference in their entirety.

In this example, the cartridge provides a negative electrode, and a positive electrode made of a deposited metal (not shown in the figure) is used with an electric field to drive the deposition process. For example, an electric field may be used to attract the CNTs to the metal substrate such that they are at least partially encapsulated by the metal composite and protrude from the deposited metal composite layer during the electroplating process. The chemical solution may also be subjected to physical energy such as agitation, bubbling, ultrasound or megasonic (megasonic) waves to facilitate mixing, addition of nonionic surfactants to prevent CNT adhesion, and the like.

After deposition, this example shows an optional set of intermediate rollers to reduce the thickness of the plate. Also, in one example, the substrate layer may be peeled away from the composite layer and then passed through the set of rollers or otherwise wound on a final shaft. The resulting structures, for example, comprising a composite layer including anchored CNTs extending at least partially therefrom, can be used to form a variety of the electrochemical power devices described herein. Moreover, the resulting structure can be cut into a variety of sizes, for example, sizes of 1mm by 1mm to 1m by 1m or greater.

In other examples, the composite layer, including the anchored CNTs, may be formed during an electroplating process without the use of a substrate. For example, the composite layer may be formed on a drum (or other component of a plating apparatus in solution) and then peeled or removed therefrom.

FIG. 10 illustrates another exemplary co-electrodeposition method of CNT and metal composite layers. This example is similar to the method described in fig. 9, however, in this example, a magnetic field is used to orient the carbon nanotubes in solution and potentially increase the density of CNTs in the composite formed on the substrate. For example, a magnet may be placed in a cylinder (drum) to attract and orient the CNTs in solution so that they become trapped in and protrude from the metal deposited on the substrate, as shown by the CNT-metal composite. This example can make CNTs protruding from the metal composite layer more aligned than in the absence of the magnetic field.

FIG. 11 illustrates another exemplary co-electrodeposition method of CNT and metal composite layers. This example is similar to the method described in fig. 10, however, in this example, an inert electrode is used in the bath to create an electric field for orienting the CNTs in solution and potentially increasing the density of CNTs in the complex formed on the substrate, similar to that described in fig. 10. Also, this example can make CNTs protruding from the metal composite layer more aligned than in the absence of the magnetic field.

Fig. 12 shows an exemplary SEM image of a structure according to certain embodiments described herein. In particular, fig. 12 shows SEM images of CNTs before and after the metallization process (i.e., adding a metal composite layer to anchor the CNTs). In particular, the tangled portions of the CNTs are anchored. Moreover, the figure includes exemplary illustrations of the different components of the structure after metallization, e.g., an aligned CNT array, which can be disposed in Li-ions as part of a Li-ion battery, the CNT array anchored in a metal layer. The structure shown in the SEM images was formed according to the method shown in fig. 7A-7D.

The embodiments of the present invention described above are merely illustrative, and do not limit the present invention. Various changes and modifications may be made without departing from the invention in its broadest aspects. The appended claims encompass such changes and modifications as fall within the true spirit and scope of this invention.

Claims (25)

1. A lithium ion battery comprising

An anode comprising a conductive composite layer and an array of carbon nanotubes, wherein at least a portion of the carbon nanotubes are anchored in and extend from the conductive composite layer; and

at least a portion of the carbon nanotube array extends from the conductive composite layer into an electrolyte solution, wherein the electrolyte solution contains silicon powder or alloyed silicon powder.

2. The lithium ion battery of claim 1, wherein the conductive composite layer comprises a carbon-metal composite.

3. The lithium ion battery of claim 1, wherein the carbon nanotubes extend from the first side and the second side of the composite layer.

4. The lithium ion battery of claim 1, wherein the portions of the array of carbon nanotubes that extend from the composite layer are aligned in a common direction.

5. The lithium ion battery of claim 1, wherein the portions of the array of carbon nanotubes that extend from the composite layer are aligned in a common direction more than the portion of the array of carbon nanotubes that is anchored in the composite layer.

6. The lithium ion battery of claim 1, wherein a portion of the array of carbon nanotubes anchored in the composite layer is misaligned.

7. The lithium ion battery of claim 1, wherein a portion of the array of carbon nanotubes anchored in the composite layer is entangled in the composite layer.

8. The lithium ion battery of claim 1, wherein the carbon nanotubes comprise multi-walled tubes.

9. The lithium ion battery of claim 1, wherein the carbon nanotubes comprise carbon nanofibers.

10. A method of forming a structure for a lithium ion battery, the method comprising the steps of:

forming a conductive composite layer having an array of carbon nanotubes, wherein

At least a first portion of the length of the carbon nanotube array protruding from the conductive composite layer; and

at least a second portion of the length of the carbon nanotube array is embedded in the conductive composite layer;

forming a layer of an electrolyte solution, wherein a first portion of the array of carbon nanotubes extends into the electrolyte solution, wherein the electrolyte solution contains silicon powder or alloyed silicon powder.

11. The method of claim 10, wherein the first portions of the lengths of the carbon nanotubes are aligned along a common direction.

12. The method of claim 10, wherein the second portion of the length of the carbon nanotubes is not aligned.

13. The method of claim 12, wherein the second portion of carbon nanotubes are entangled in a conductive composite layer.

14. The method of claim 12, further comprising forming the array of carbon nanotubes in a template having holes for aligning the carbon nanotubes during carbon nanotube formation.

15. The method of claim 14, further comprising removing the template.

16. The method of claim 10, further comprising forming the array of carbon nanotubes by a chemical vapor deposition process.

17. The method of claim 10, further comprising passing the substrate through an electrochemical bath comprising carbon nanotubes in solution, and electroplating a conductive layer to the substrate, wherein the conductive layer comprises the array of carbon nanotubes.

18. The method of claim 10, further comprising forming the conductive layer in an electrochemical bath comprising carbon nanotubes in solution.

19. The method of claim 18, wherein the conductive layer is formed on a portion of an electrochemical device and subsequently removed therefrom.

20. A method of forming a structure for a lithium ion battery, the method comprising the steps of:

passing the substrate through an electroplating solution having carbon nanotubes dispersed therein; and

electroplating a conductive composite layer having carbon nanotubes therein onto a substrate, wherein the carbon nanotubes at least partially protrude from the conductive composite layer;

forming a layer of an electrolyte solution, wherein the carbon nanotubes protrude from the conductive composite layer into the electrolyte solution, wherein the electrolyte solution contains silicon powder or alloyed silicon powder.

21. The method of claim 20, further comprising forming a magnetic field in the electroplating solution to at least partially align the carbon nanotubes when electroplating the conductive composite layer.

22. The method of claim 20, further comprising forming an electric field in the electroplating solution to at least partially align the carbon nanotubes when electroplating the conductive composite layer.

23. The method of claim 20, further comprising forming a magnetic field in the electroplating solution to increase the density of the carbon nanotubes in the solution when electroplating the conductive composite layer.

24. The method of claim 20, further comprising forming an electric field in the electroplating solution to increase the density of the carbon nanotubes in the solution when electroplating the conductive composite layer.

25. The method of claim 20, wherein the method comprises a roll-to-roll process.