WO2017188650A1 - Membrane-integrated fibrous electrode structure, fibrous battery comprising same, and method for manufacturing same fibrous electrode structure - Google Patents

Abstract

The present invention relates to a membrane-integrated fibrous electrode structure, a fibrous battery comprising the same, and a method for manufacturing the same fibrous electrode structure, the membrane-integrated fibrous electrode structure comprising: a conductive fiber including a carbon component; an active material layer covering the outer surface of the conductive fiber; and a membrane formed on the active material layer.

Description

Separator integral fibrous electrode structure, fibrous battery comprising the same, and method of manufacturing the fibrous electrode structure

It relates to a conductive fiber comprising a carbon component, an active material layer covering the outer surface of the conductive fiber, a membrane-like electrode structure comprising a separator formed on the active material layer, a fibrous battery comprising the same, and a method of manufacturing the fibrous electrode structure. .

With the emergence of new applications such as wellness-oriented healthcare, telemedicine-based medical care, advanced military systems, and portable smart electronic devices, the demand for wearable smart electronic devices is increasing. Such wearable electronic devices are realized only when integrated with a wearable energy storage device capable of driving them, but development of wearable batteries is delayed compared to electronic devices such as smart glasses and sensors that are already in the product development stage. Currently, wearable devices are flexible, attachable, and can be said to be a true wearable device only when fabricated or fabricated devices are fabricated.

Fabric batteries are widely used in wearable energy storage devices capable of driving wearable / portable devices, and wearable electronic devices such as smart glasses and smart wearable devices such as portable electronic devices. Wearable fabric batteries, unlike traditional cell research, which focused on electrochemical performance, require various indicators of batteries, and therefore, develop customized technologies. Wearable fabric batteries have been focused on achieving safety and high energy density with physical flexibility (bending) and stretch-shrinkability.

In the case of the cable type developed with the conventional fabric battery, it is difficult to achieve high energy density because the positive-cathode is formed on one cable wire and its contact area is limited. Moreover, it was heavy by use of a metal cable, and the drape property as a fiber was not good. In addition, a positive electrode and a negative electrode fiber based wearable battery, in which an active material is coated on a CNT sheet and twisted in a fiber form, has been reported, but expensive equipment is used in synthesizing the CNT sheet, resulting in a process cost. In addition, the fibrous battery was fabricated by winding the cathode and anode fibers at regular intervals as shown in FIG. 2, but has a disadvantage in that energy distance is difficult to increase because the distance between the two electrodes is far.

Therefore, while achieving a high energy density, there is a need for the development of a fibrous electrode with improved adhesion by controlling the interface between the materials.

One aspect of the present invention is to provide a membrane-integrated fibrous electrode structure capable of realizing high energy density and improving interfacial properties.

Another aspect of the present invention is to provide a fibrous battery comprising the separator integrated fibrous electrode structure.

Another aspect of the present invention is to provide a method for producing the membrane-integrated fibrous electrode structure.

In one aspect of the invention,

Conductive fibers comprising a carbon component;

An active material layer covering an outer surface of the conductive fiber; And

A separator covering an outer surface of the active material layer;

There is provided a membrane-integrated fibrous electrode structure comprising a.

In another aspect of the invention,

A bioadhesive is introduced between the conductive fiber and the active material layer, between the active material layer and the separator, and at least one of the inside of the active material layer,

The bioadhesive is provided with a fibrous electrode structure comprising a phage on which a peptide having a binding capacity to a carbon material is displayed.

According to one embodiment, the phage may be a phage genetically engineered to have a binding capacity to the carbon material.

According to one embodiment, the bioadhesive may have a sheet form.

According to an embodiment, the internal structure of the sheet may have a percolated network structure.

According to one embodiment, the gripping may be a filamentous gripping.

In another aspect of the present invention, there is provided a fibrous battery comprising the separator integrated fibrous electrode structure.

According to one embodiment, the fibrous battery includes a positive electrode including one or more of the fibrous electrode structure; And a cathode electrode including one or more fibrous electrode structures, wherein the anode electrode and the cathode electrode may be twisted, overlapped, or woven with each other.

In another aspect of the invention,

Providing a conductive fiber comprising a carbon material;

Forming an active material layer on an outer surface of the conductive fiber; And

Forming a separator on an outer surface of the active material layer;

Provided is a method of manufacturing a separator-integrated fibrous electrode structure comprising a.

Also,

Introducing a bioadhesive comprising a phage having a peptide having a binding capacity to a carbon material between the conductive fiber and the active material layer, between the active material layer and the separator, and at least one of the inside of the active material layer. A method for producing a fibrous electrode structure is provided.

According to an embodiment, the forming of the active material layer and the forming of the separator may include a continuous process of allowing the conductive fiber to pass through the active material-containing container and the separator-containing container continuously.

According to an embodiment, the method may further include pressing after forming the fibrous separator.

The membrane-integrated fibrous electrode structure can implement a high energy density and can improve the interface properties.

In the method of manufacturing the membrane-integrated fibrous electrode structure, the active material is dispersed in a solvent, thereby allowing continuous coating on the conductive fiber.

In addition, the method of manufacturing the fibrous electrode structure may improve the interface between the conductive fiber and the active material, and the interface between the active material and the separator by coating and drying the separator on the active material.

1 is a conceptual diagram of a membrane-integrated fibrous electrode structure and a fibrous battery including the same according to one embodiment.

2 is a schematic view of a conventional fibrous battery.

Figure 3 is a schematic view of the carbon fiber-active material-membrane step coating process according to one embodiment.

4 is a conceptual diagram of a pressing process according to an embodiment.

5 is a conceptual diagram of a fibrous battery including a pressing process according to an embodiment.

6 is a view showing the results of analyzing the adhesive properties on the substrate of the carbon nanotube film by applying a bioadhesive according to one embodiment.

7 is a view showing a SEM image of the active material coating properties change and the fibrous electrode structure coated with the active material according to the presence or absence of the bioadhesive according to one embodiment.

8 is a view showing the charge and discharge characteristics of the positive electrode fibrous electrode structure using a bioadhesive according to one embodiment.

9 is a view showing the charge and discharge characteristics after bending of the positive electrode-like electrode structure using a bioadhesive according to one embodiment.

10 is a view showing charge and discharge characteristics of the negative electrode fibrous electrode structure using a bioadhesive according to one embodiment.

11 is a view showing charge and discharge characteristics of a membrane-integrated fibrous full cell according to one embodiment.

12 is a view illustrating a voltage retention rate at 1000 bending times of a membrane-integrated fibrous full cell according to one embodiment.

FIG. 13A illustrates a bend evaluation picture of a fibrous full cell using a bioadhesive according to one embodiment, and FIG. 13B illustrates charge and discharge characteristics after bending of the fibrous complete cell.

14A and 14B are SEM images illustrating an effect of improving interfacial properties of a fibrous electrode structure coated with a cathode active material using a bioadhesive according to one embodiment.

15A and 15B are SEM images showing cross sections of a fibrous electrode structure before and after pressing, respectively, according to one embodiment.

16A and 16B are diagrams showing charge and discharge improvement characteristics of the anode fibrous electrode structure before and after applying the pressing process according to one embodiment, respectively.

Hereinafter, a fibrous electrode structure, a fibrous battery including the same, and a manufacturing method thereof according to an embodiment will be described in detail with reference to the accompanying drawings.

Fibrous electrode structure according to one embodiment,

Conductive fibers comprising a carbon component; An active material layer covering an outer surface of the conductive fiber; And a separator covering an outer surface of the active material layer.

In addition, a bioadhesive is introduced between the conductive fiber and the active material layer, between the active material layer and the separator, and at least one of the inside of the active material layer, and the bioadhesive is a phage in which a peptide having a binding ability to a carbon material is displayed. It may include.

1 is a conceptual diagram of a membrane-integrated fibrous electrode structure and a fibrous battery including the same according to an embodiment, wherein a single electrode thread of each of an anode and a cathode is coated by coating a separator on a conductive fiber-active material layer. Thus, there is an effect that can be directly contacted without fear of short circuit. In such a membrane-integrated structure, the gap between electrodes is narrow due to the direct contact of the anode chamber and the cathode chamber, which is advantageous for high energy density.

In addition, Figure 1 is a bioadhesive in the fibrous electrode structure according to an embodiment is introduced between the conductive fiber and the active material layer as an example.

Referring to FIGS. 4 and 15, the fibrous electrode may have a flat shape through a pressing process.

The conductive fiber including the carbon component serves as a current collector in the core of the fibrous electrode structure, and may be, for example, a conductive carbon fiber, a carbon component-containing conductive polymer fiber, or a carbon component-containing conductive metal fiber. When the conductive fiber is a conductive polymer fiber, or a conductive metal fiber, the surface of the fiber may have a binding capacity to the carbon material, or a peptide having a binding capacity to the carbon material may have a binding capacity to the displayed phage.

The conductive metal fiber may be, for example, SUS fiber, Al, Cu, or Ni fiber. In addition, the "conductive polymer" is an electrically conductive polymer capable of forming a fiber structure among them. The conductive polymer is a molecule capable of producing fibers while being conductive, for example, after being dissolved in a solvent, electrospinning, wet spinning, conjugate spinning, melt blown spinning ) Or a molecule capable of producing a fiber when spun by conventional spinning methods including flash spinning, and the like. The conductive polymer may be selected from the group consisting of polyacetylene, polypyrrole, polythiophene, polyethylenedioxythiophene, polyphenylenevinylene, polyphenylene, polysilane, polyfluorene, polyaniline and poly sulfur nitride, for example. Can be.

The active material layer includes an active material.

In one embodiment, the active material layer may include a composite of the active material and the graticule material. The active material may have a nanometer size, and the strain due to external physical deformation may be minimized through hybridization with a two-dimensional flexible material such as graphene.

When the active material layer is a positive electrode, for example, LiCoO ₂ , LiNiO ₂ , LiMn ₂ O ₄ , LiCoPO ₄ , LiFePO ₄ , LiMnPO _{4 ,} LiNi _x Mn _y Co _z O ₂ (Where 0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ z ≦ 1, where x + y + z = 1), FeF ₃ , FeOF, BiF ₃ , BiOF, polyimide (PI), quinone (example : benzoquinone), and pyromellitic diimide may include at least one selected from the group consisting of. When the active material layer is a negative electrode, for example, carbon, Si, SiO ₂ , SnO ₂ , Co ₃ O ₄ , Li ₄ Ti ₅ O ₁₂ (LTO), MoS ₂ , activated carbon, graphene, doped graphene, carbon It may include at least one selected from the group consisting of nanotubes, and modified carbon nanotubes.

The electrolyte layer may include a gel electrolyte, a solid electrolyte, a liquid electrolyte, or a combination thereof. In addition, the electrolyte layer may be a lithium salt is dissolved. The gel electrolyte may include, for example, PEO, PVdF, PVdF-HFP, PMMA, PAN, PVAC, or a combination thereof. The solid electrolyte may include, for example, PEO, PVdF, polypropylene oxide (PPO), polyethylene imine (PEI), polyethylene sulphide (PES), polyvinyl acetate (PVAc), or a combination thereof. The lithium salt is for example LiCl, LiBr, LiI, LiClO ₄ , LiBF ₄ , LiB ₁₀ Cl ₁₀ , LiPF ₆ , LiCF ₃ SO ₃ , LiCF ₃ CO ₂ , LiAsF ₆ , LiSbF ₆ , LiAlCl ₄ , CH ₃ SO ₃ Li, CF ₃ SO ₃ Li, (CF ₃ SO ₂ ) ₂ NLi, chloroborane lithium, lower aliphatic carbonate, lithium tetraphenyl borate, or combinations thereof. In addition, the electrolyte layer may further include an additive for controlling physical deformation characteristics.

The separator may be replaced with the gel electrolyte or solid electrolyte layer. This is because the gel electrolyte or solid electrolyte layer can itself function as a free-standing separator.

The liquid electrolyte is for example ethylene carbonate (EC): dimethyl carbonate (DMC), diethylene carbonate (DEC), EC-DEC, EC-DEC-DMC, propylene carbonate (PC), butylene carbonate , Dimethoxy ethane (DME), 1,2-dimethoxy ethane, diethylene glycol dimethylene ether (DEGDME), acetonitrile, dimethyl sulfoxide (DMSO), methyl acetate (MA), methyl formate (MF), tetra Hydrofuran (THF), N-methyl-2-pyrrolidinone, gamma-butylo lactone, 2-methyl tetrahydrofuran, dimethyl sulfoxide, 1,3-dioxolon, formamide, dimethylformamide, nitromethane Methyl acetate, phosphate triester, trimethoxy methane, dioxorone derivative, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, propylene carbonate derivative, tetrahydrofuran derivative, ether , Methyl pyionate, ethyl propionate or combinations thereof Can be.

The liquid electrolyte may include, for example, ethylene carbonate (EC): dimethyl carbonate (DMC), EC-DEC, EC-DEC-DMC, or a combination thereof.

The bioadhesive may include a phage on which a peptide having a binding ability to a carbon material is displayed, and a carbon material.

Bonding with an electrochemical device (eg, conductive fiber) using the bioadhesive is performed between an electrochemical device (eg, conductive fiber) comprising a peptide and a carbon material displayed on the envelope protein or fragment thereof. It may include what has been made.

In another embodiment, phages that display peptides that have a binding capacity to the carbon material specifically bind to the carbon material, so that additional functions can be imparted in a non-destructive manner that does not impair the properties of these carbon materials, It can be introduced at the interface of each component of the device to improve the adhesive properties or the interface properties. For example, when the bioadhesive is introduced between the conductive fiber and the active material layer, the active material may be further attached to the conductive fiber to coat the active material thickly. For example, when the bioadhesive is introduced into the active material layer, interfacial peeling of the active material layer can be prevented. As such, the bioadhesive may improve adhesion characteristics between the conductive fibers of the fibrous electrode structure and the active material layer, between the active material layer and the separator, or improve the interfacial properties of the active material layer.

The carbonaceous material may comprise a graphical material. As used herein, the term "graphitic materials" refers to a material having a surface on which carbon atoms are arranged in a hexagonal shape, that is, a graphitic surface. It can be included in graffiti materials regardless of their chemical, chemical or structural properties. The graphitic material may be, for example, graphene sheets, highly oriented pyrolytic graphite (HOPG) sheets, single-walled carbon nanotubes, double-walled carbon nanotubes), carbon nanotubes such as multi-walled carbon nanotubes, fullerenes, or combinations thereof. The graphitic material may be a metallic, semiconducting or mixed material. For example, a mixture of graphene sheets and single layer carbon nanotubes may be used.

The peptide that binds to the carbon material may be a material that binds non-destructively with the carbon material. The peptide can be selected via a library of peptides, eg, via phage display techniques. Phage display techniques allow peptides to be genetically linked, inserted or substituted into the phage coat protein and displayed outside of the phage, and the peptide can be encoded by genetic information in the virion. Proteins of various variants can be screened and selected by the displayed protein and the DNA encoding it, which is referred to as "biopanning". In summary, biopanning techniques are specific by reacting phages with various variants displayed with immobilized targets (e.g., carbon materials), washing unbound phages, and disrupting the binding interaction between phages and targets. And eluting the bound phages. A portion of the eluted phage can be left for DNA sequencing and peptide identification, and the remainder can be amplified in vivo and the sub library for the next round repeated to repeat the process.

The term "phage" or "bacteriophage" is used interchangeably and may refer to a virus that infects bacteria and replicates within bacteria. Phage or bacteriophage may be used to display peptides that selectively or specifically bind to carbon materials. The phage may be genetically engineered such that a peptide having a binding capacity to the carbon material is displayed on the envelope protein or fragment thereof. In the present invention, the term "genetic engineering" or "genetically engineered" refers to one or more genes relative to a phage to display a peptide having the ability to bind a carbon material to the envelope protein or fragment thereof of the phage. It may refer to the act of introducing a genetic modification or a phage made by it. The genetic modification includes the introduction of a foreign gene encoding the peptide. In addition, the phage may be a filamentous phage, for example, M13 phage, F1 phage, Fd phage, If1 phage, Ike phage, Zj / Z phage, Ff phage, Xf phage, Pf1 phage or Pf3 It may be a phage.

As used herein, the term “phage display” or “phage displayed phage” may refer to the display of functional foreign peptides or proteins on the surface of phage or phagemid particles. The surface of the phage may refer to the envelope protein or fragment thereof of the phage.

The functional foreign peptide may be present in binding to the N-terminus of the envelope protein of the phage or inserted into the envelope protein. The phage may also be linked to the C-terminus of the functional foreign peptide to the N-terminus of the phage coat protein, or the peptide is inserted between contiguous amino acid sequences of the phage coat protein or to the contiguous amino acid sequence of the coat protein. It may be a phage that is substituted a part of. The position of the contiguous amino acid sequence into which the peptide is inserted or substituted into the envelope protein is 1-50 positions, 1-40 positions, 1-30 positions, 1-20 positions, and 1-to-N from the N-terminus of the coat protein. Position 10, positions 2 to 8, positions 2 to 4, positions 2 to 3, positions 3 to 4, or positions 2; In addition, the envelope protein may be p3, p6, p8 or p9.

Peptides that specifically bind to the carbon material include X ₂ SX ₁ AAX ₂ X ₃ P (SEQ ID NO: 1), X ₂ X ₂ PX ₃ X ₂ AX ₃ P (SEQ ID NO: 2), SX ₁ AAX ₂ X ₃ It may be a peptide or a peptide set comprising at least one selected from the group consisting of the amino acid sequence of P (SEQ ID NO: 3) and X ₂ PX ₃ X ₂ AX ₃ P (SEQ ID NO: 4). In addition, the peptide or peptide set may be a peptide or peptide set including one or more selected from the group consisting of the amino acid sequences of SEQ ID NOs: 5-8. A contiguous amino acid sequence of the coat protein of the phage may be linked to the N-terminus or C-terminus of the amino acid sequence of the peptide or peptide set. Thus, for example, the peptide or set of peptides may comprise 5 to 60 amino acid sequences, 7 to 55 amino acid sequences, 7 to 40 amino acid sequences, 7 to 30 amino acid sequences, 7 to 20 amino acid sequences, or It may be 7 to 10 amino acid sequences.

The peptide may include conservative substitutions of the disclosed peptides. As used herein, the term "conservative substitution" refers to the substitution of a first amino acid residue with a second, different amino acid residue without altering the biophysical properties of the protein or peptide, wherein the first and second Amino acid residues may mean having side chains with similar biophysical characteristics. Similar biophysical features may include the ability to provide or accept hydrophobicity, charge, polarity, or hydrogen bonding. Examples of conservative substitutions include basic amino acids (arginine, lysine and histidine), acidic amino acids (glutamic acid and aspartic acid), polar amino acids (glutamine and asparagine), hydrophobic amino acids (leucine, isoleucine, valine and methionine), hydrophilic amino acids (aspart) Acids, glutamic acid, asparagine and glutamine), aromatic amino acids (phenylalanine, tryptophan, tyrosine and histidine), and small amino acids (glycine, alanine, serine and threonine). Amino acid substitutions that generally do not alter specific activity are known in the art. Thus, for example, in the peptide X ₁ may be W, Y, F or H, X ₂ may be D, E, N or Q, and X ₃ may be I, L or V.

Thus, for example, the 50-amino acid length p8 in which the C-terminus of the peptide of any one of SEQ ID NO: 1 to SEQ ID NO: 8 is present in the body of the M13 phage, ie, in the longitudinal body, not at the end of the phage It may be connected to the N-terminus of (SEQ ID NO: 19). Further, for example, the peptide of any one of SEQ ID NO: 1 to SEQ ID NO: 8 amino acid sequence of position 2 to 4 of the coat protein p8 of M13 phage (ie EGD), position 2 to 3, position 3 to 4 Or may be linked in place of the amino acid sequence at position 2.

In another embodiment, the phage can be arranged directionally on the surface of the carbon material using the filamentary structure of the gripping itself. For example, they may be arranged in a line in a specific direction, in which case the binding force between the peptide and the carbon material surface located in the envelope protein of the phage may be increased and aligned at the same time. Date-aligned phage can impart anisotropic functionalization to the surface of the carbon material, which is different from only isotropic or random functionalization when using only peptides. In addition to the linear alignment structure as described above, it is possible to form a structure having a specific direction such as a layer structure, nematic structure, spiral structure, lattice structure such as smectic structure, carbon material according to the arrangement structure of the phage Various functions can be imparted on the surface.

In another embodiment, the bioadhesive may be in the form of a sheet. As used herein, the term "sheet" may refer to a material having a constant width and thickness, and may be understood as a concept including a film, a web, a film, or a composite structure thereof. The area of the sheet may be, for example, 0.0001 to 1000 cm ² , 0.0001 to 100 cm ² , or 1 to 20 cm ² , and the thickness may be, for example, 20 to 400 nm, 40 to 200, or 40 to 100. nm. In addition, the inner structure of the sheet may have a percolated network structure. As used herein, the term "percolated network" may refer to a lattice structure composed of random conductive or non-conductive connections.

The bioadhesive facilitates coating of the active material on the conductive fiber, prevents peeling of the active material at the interface of each layer, and improves adhesion characteristics between the active material particles, thereby improving performance stability due to external deformation of the fabric battery. It works.

Accordingly, in the fibrous electrode structure, a bioadhesive having a one-dimensional wire structure is introduced at the interface between the conductive fiber and the active material or the active material and the separator, and the active material particles inside the active material layer, thereby improving the interfacial properties and peeling the active material at the interface of each layer. Has the effect of being prevented.

According to one embodiment, the fibrous electrode structure is a membrane integrated. The separator is well known in the art, polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP), microporous polytetrafluoroethylene, microporous polyethylene oxide, microporous polyester, microporous polyethylene, microporous polypropylene , Microporous ethylene-propylene copolymer, polypropylene / polyethylene of microporous two-layer structure, polypropylene / polyethylene / polypropylene membrane of microporous three-layer structure, and the like. Moreover, the separator in which aramid resin was apply | coated to the said separator, or the separator in which resin containing polyamideimide and an alumina filler were apply | coated, etc. can also be used. By coating a separator on the conductive fiber-active material layer, a single electrode thread for each of the positive electrode and the negative electrode is possible, so that there is an effect of being able to directly contact without a short circuit fear. Further, in such a structure, the distance between the electrodes can be narrowed by direct contact between the anode chamber and the cathode chamber, and high line energy density can be achieved by the multiple weaving method.

In addition, the membrane-integrated fibrous electrode has an effect of improving physical contact between the conductive fiber and the active material, between the active material and the separator in the process of coating and drying the separator on the active material.

The membrane-integrated fibrous electrode may be further flattened through a pressing process. In the case of a flat shape, the contact property between the electrode and the active material is improved to achieve a high energy density. In addition, the flat yarn can be stacked with a plurality of negative electrode and the positive electrode can achieve a high line energy density.

A fibrous battery according to another aspect includes the aforementioned fibrous electrode structure.

Referring to FIG. 1, the fibrous battery includes a positive electrode including at least one membrane-integrated fibrous electrode structure, and a negative electrode including at least one membrane-integrated fibrous electrode structure, wherein the positive electrode and the negative electrode May be twisted or woven together.

Referring to FIG. 5, the fibrous battery includes a cathode electrode including at least one separator-integrated fibrous electrode structure, and a cathode electrode including at least one separator-integrated fibrous electrode structure, and includes a plurality of cathodes and a plurality of cathodes. A positive electrode may be stacked to form a battery. In this case, there is an effect of increasing the line energy density of the fibrous electrode.

The fibrous electrode structure is as described above.

In the fibrous battery, one positive electrode and one negative electrode are used as one unit cell, and the plurality of unit cells can be twisted together to form a battery. A plurality of negative electrodes and a plurality of positive electrode electrodes are simultaneously twisted to form a battery. You may.

In one embodiment, the fibrous battery may achieve a high energy density by allowing a thin film separator to be coated on the surface of the conductive fiber-active material layer structure to enable direct contact between the positive electrode and the negative electrode.

In addition, the fibrous battery may be a secondary battery, for example, a lithium secondary battery. The structure of the active material layer, electrolyte layer, and separator for a lithium secondary battery is as described above.

Another aspect provides a method of manufacturing the fibrous electrode structure.

The manufacturing method of the fibrous electrode structure, providing a conductive fiber comprising a carbon component; Forming an active material layer on an outer surface of the conductive fiber; And forming a separator on an outer surface of the active material layer.

In one embodiment, a bio-adhesive comprising a phage having a binding ability to a carbon material is displayed between the conductive fiber and the active material layer, between the active material layer and the separator, and at least one of the inside of the active material layer. It further includes the step of introducing.

In one embodiment, when the bio adhesive is introduced between the conductive fiber and the active material layer, it can be coated on the outer surface of the conductive fiber using a solution in which the bio adhesive is dispersed in a solvent. The coating can use any known coating method without limitation.

In another embodiment, when the bioadhesive is introduced into the active material layer, the bioadhesive may be dispersed together when preparing a composition for forming the active material layer by dispersing the active material in a solvent.

Meanwhile, referring to FIG. 3, the forming of the active material layer and the forming of the separator may be performed by a continuous process of continuously passing conductive fibers through the active material-containing container and the electrolyte-containing container.

According to one embodiment, as shown in Figures 4 and 5, it may further comprise a step of pressing after forming the separator. Through this process, it is possible to stack a plurality of fibrous electrodes.

According to the method of manufacturing the fibrous electrode structure according to one embodiment, the active material is dispersed in a solvent to be continuously coated on the conductive fiber.

Exemplary embodiments are described in more detail through the following examples and comparative examples. However, the examples and the comparative examples are for illustrating the technical idea and the scope of the present invention is not limited only to these.

Example  1. Fabrication of bioadhesives for electrochemical devices and analysis of their adhesion and interfacial activity

1.1. Bio glue (on carbon materials Binding capacity  Preparation of Phage Displayed with Peptides)

Phage (P8GB # 1) displayed with DSWAADIP (SEQ ID NO: 5), a peptide having a strong binding force with a carbon material as a bioadhesive, phage (p8GB # 5) displayed with DNPIQAVP (SEQ ID NO: 6), SWAADIP (SEQ ID NO: 7) , And NPIQAVP (SEQ ID NO: 8) displayed phage were prepared by the following method.

First, oligonucleotides of SEQ ID NOs: 10 and 11 for site-directed mutation of C to G, the 1381th base pair of M13KE vector (NEB, product # N0316S) (SEQ ID NO: 9) M13HK vector was prepared using The prepared M13HK vector was double-digested using restriction enzymes BspHI (NEB, product # R0517S) and BamHI restriction enzyme (NEB, product # R3136T), using Antarctic phosphatase. Dephosphorylation. The dephosphorylated vector was linked by incubation at 16 overnight with a double-cut DNA duplex. The product was then purified and concentrated. The electrocompetent cells (XL-1 Blue, Stratagene) were transformed by electroporation with 2 μl of concentrated linked vector solution at 18 kV / cml and a total of 5 transformations were performed for library construction. It was. Subsequently, the transformed cells were incubated for 60 minutes, and fractions of the multiple transformants were X-gal / isopropyl-β-D-1-thiogalactopyranoside (IPTG) / tetracycline (Tet). Plated on the containing agar plate to determine the diversity of the library. The remaining cells were amplified for 8 hours in shake incubator. Oligonucleotides of SEQ ID NOs: 12 and 13 were used to construct the phage display p8 peptide library.

The base sequence of the phage display p8 peptide library prepared according to one embodiment had a variety of 4.8 × 10 ⁷ plaque form units (pfu) and had 1.3 × 10 ⁵ copy numbers per sequence. .

Next, a HOPG (highly ordered pyrolytic graphite) substrate (manufacturer: SPI product # 439HP-AB) having a diameter of 1 cm was prepared. In this case, a relatively large HOPG substrate having a grain size of 100 μm or less was used as the HOPG substrate. HOPG was stripped from the substrate to the tape before the experiment to obtain a fresh surface to minimize defects due to oxidation of the sample surface and the like. Next, a phage display p8 peptide library of 4.8 × 10 ¹⁰ pfu (4.8 × 10 ⁷ variants, 1000 copies of each sequence) prepared above was prepared in 100 μL of Tris-Buffered Saline (TBS) buffer. Conjugating with HOPG surface in shaker at 100 rpm for 1 hour. After 1 hour the solution was removed and then washed 10 times in TBS. After washing the surface of the washed HOPG as acidic buffer with Tris-HCl pH 2.2 for 8 minutes to remove the non-selectively reacting peptide, XL-1 blue E. in the mid-log state. Elution for 30 minutes in coli culture. Part of the eluted culture was left for DNA sequencing and peptide identification and the remainder was amplified to create a sub-library for the next round. The above process was repeated using the created sub library. On the other hand, the plaques left were analyzed for DNA to obtain a p8 peptide sequence, and the obtained sequences were analyzed to obtain phage in which any one of SEQ ID NOs: 5 to 8 having strong binding ability to a carbon material was displayed.

1.2 Improvement of Interfacial Adhesion Characteristics by Bio Adhesives

The bioadhesive according to one embodiment is a bacterio phage having a one-dimensional linear structure, and in particular, has excellent adhesive properties to carbon materials. Therefore, in this embodiment, the adhesive properties were analyzed using P8GB # 1 M13 bacteriophage.

Specifically, in order to test the adhesive properties of the bio-adhesive, 5 × 10 ¹² M13 phages were mixed in 1.3 mg carbon nanotubes (CNT) and dispersed in water to prepare a mixed solution. Thereafter, the mixed solution was dropped to a certain amount of PET as a plastic substrate to produce a film. As a comparative example, a film was prepared by dropping a solution containing CNT on PET without M13 phage, and the results are shown in FIG. 6.

As shown in FIG. 6, when the bioadhesive according to Example 1.1 is not added, the CNT film is peeled off from the PET substrate, whereas when the bioadhesive according to Example 1.1 is added, the CNT film adheres well to the PET substrate. It could be confirmed. As a result, it can be seen that the bioadhesive according to one embodiment may be usefully used for the bioadhesive for an electrochemical device.

1.3. Bio adhesive coating method on conductive fibers .

In order to improve the mechanical and electrical adhesion properties between the conductive fiber and the active material, a solution containing a single carbon nanotube and a P8GB # 1 phage solution was coated on the conductive fiber.

To this end, first, an aqueous solution prepared by adding sodium cholate (sodium-cholate) as a surfactant to distilled water at a concentration of 2% w / v was prepared, followed by carbon nanotubes (manufacturer: Nanointegris, SuperPure SWNTs, solution form, concentration: 1 mg / mL) was dialyzed for 48 hours to prepare a colloidal solution in which a single carbon nanotube was stabilized with sodium cholate. At this time, assuming that the average length of single-walled carbon nanotubes (CNT) is 1 μm and the average diameter is 1.4 nm, the concentration of the single-walled carbon nanotubes is as follows.

[Equation 1]

Single carbon nanotubes (pcs / ml) = concentration μg / ml X 3 X 10 ¹¹ CNT

According to the above equation, it can be seen that the number of single carbon nanotubes included in the colloidal solution is (3 × 10 ¹⁴ ) / ml. After mixing 0.2 mL solution (3 × 10 ¹⁴ / mL) of the single carbon nanotube and 0.15 mL (1 × 10 ¹⁴ / mL) of the above p8GB # 1 phage solution into 10 mL of 1% w / v sodium cholate solution, The carbon fibers were soaked for 24 hours and then taken out and dried in air.

Example 2 Preparation and Properties of Fibrous Electrode Structures Comprising Bioadhesives

2.1 Improvement of coating properties of active material after introduction of bio glue

In the process of coating the positive electrode active material on the conductive fiber used as the core current collector, the difference in coating properties according to the presence or absence of the introduction of the bioadhesive was examined. In this embodiment, a carbon fiber bundle was used as a core current collector, and a LiFePO ₄ -rGO hybrid composite was used as an active material by using a graphene oxide (rGO), which is a two-dimensional support, to enhance flexibility of the active material. . Hybridization with graphene enhances the flexibility of the active material and at the same time assists in the nanoparticle formation of LiFePO ₄ and improves the conductivity of the positive electrode. The active material coating on the conductive fiber was filled with an active material ink in a glass tube having a predetermined diameter using a die-coating method, and the active material was coated by passing the glass tube at a constant speed. In this case, as shown in FIG. 3, the membrane coating may be continuously performed after coating the active material.

Here, the active material ink is a solvent NMP (N-Methyl-2) by mixing 70 wt% of the LiFePO ₄ -rGO particles and 10 wt% of polyvinylidene fluoride (PVDF) as a polymer binder with 20 wt% of Super P carbon (SP), a conductive carbon additive. -pyrrolidone) to prepare. Bio adhesive is first coated on the carbon fiber before coating the active material on the carbon fiber bundle, it was coated in the same manner as in Example 1.3. At this time, the coating properties of the active material according to the presence or absence of the bioadhesive was compared.

As shown in Figure 7, when the bio-adhesive under the same die-coating conditions, it can be seen that the active material is further attached to the conductive fiber is coated thick. This is a result of the use of bioadhesive to improve the wettability and adhesion of the active material ink to the fibers.

2.2 Fabrication and characterization of the fibrous bipolar electrode structure

The active material layer was coated on the conductive fiber coated with the bioadhesive, and then the separator was coated to examine the characteristics of the anode fibrous electrode structure. The separator used in this embodiment may be replaced with a gel electrolyte. In addition, the gel electrolyte may be applied by coating the fibrous cathode. Gel electrolyte contains Bis (trifluoromethane) sulfonimide lithium salt (LiTFSI) in poly (ethylene oxide) (PEO) and succinonitrile (SN) is added as a plasticizer. Gel electrolyte was coated by the die-coating method.

As a result, as shown in Figure 8, when the thickness of the anode fibrous electrode structure was 100 μm it was confirmed that it has a linear density of 0.107 mAhcm ^{- 1} , it was confirmed that it has a stable charge and discharge characteristics even in repeated measurements. Here, charging and discharging were performed by applying a current of 0.68 mA to a 4 cm long anode fiber electrode. In addition, as shown in Figure 9, it was shown that charging and discharging is possible even when the bipolar fibrous electrode structure is bent to have a bending radius of 1 cm.

Here, charging / discharging conditions were performed by applying 0.27 mA of current to the 6.5 cm long anode fiber.

2.3 Fabrication and Properties of Fibrous Cathode Electrode Structures

The active material layer was coated on the conductive fiber coated with the bioadhesive, and then the porous separator was coated to examine the characteristics of the negative electrode fibrous electrode structure. The porous separator may be applied by coating on a fibrous anode. The porous separator used in this embodiment is formed using a phase inversion phenomenon in a solution consisting of polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) -acetone-water. The porous separator was coated by the die-coating method.

As a result, as shown in Figure 10, when the diameter of the negative electrode active material coating tube 1.8 mm was confirmed to have a linear density of 0.72 mAhcm ^{- 1} , it was confirmed that it has a stable charge and discharge characteristics even in repeated measurements. Here, charging and discharging were performed by applying a current of 0.3 mA to the anode fiber electrode having a length of 3 cm.

2.4 Fabrication and Characterization of Fibrous Complete Cells

The fibrous complete cell was fabricated using the positive electrode fibrous structure and the negative electrode fibrous structure coated with the PVDF-HFP-based porous separator prepared above. In order to further strengthen the physical contact between the anode fibrous structure and the cathode fibrous structure, the fibrous positive and negative electrode structures were contacted adjacently, and then the PVDF-HFP porous separator was further coated to form a fibrous anode-cathode-integral structure. As a liquid electrolyte, ethylene carbonate (EC): dimethyl carbonate (DMC) = 1: 1 volume ratio of 1 M LiTFSI dissolved was used. This fibrous battery structure was assembled in the form of a beaker cell, a pouch cell, a tube cell and the like. As a result, as shown in FIG. 11, when the positive and negative electrode active material coated tubes were 2.0 mm, it was confirmed that the fibrous complete cell linear density was 1.45 mAhcm ⁻¹ , and that the charging and discharging characteristics were stable even in repeated measurements. Here, charging and discharging were performed by applying a current of 0.4 mA to a 4 cm long fibrous battery. In addition, it was confirmed that the voltage retention rate was very stable as shown in FIG. 12 when the 1000 repeated bend evaluation of the fibrous complete cell when the positive and negative electrode active material coated tube was 1.4 mm. 13A and 13B show that the same fibrous complete cell as used in FIG. 12 shows stable charge-discharge characteristics at a bending diameter of 10 mm.

Example 3 Bio-adhesive based Interfacial Reinforcement Coating

The bioadhesive proposed in one embodiment may form a network structure formed by self-assembly in the form of a primary nanowire. The self-assembling network has nano-sized pores so that the Li ions can escape, but the active material can not pass through, thereby acting as an interfacial reinforcing film that can prevent the peeling of the active material without interfering with the movement of Li ions. Can be.

0.2% solution of single-ply carbon nanotubes according to Example 1.3 (3 × 10 ¹⁴ / mL) and 0.15 mL (1 × 10 ¹⁴ / mL) of the p8GB # 1 phage solution 1% w / v sodium cholate (sodium) After mixing in 10 mL of the cholate solution, the mixture was placed in a semipermeable dialysis membrane (SpectrumLab, MWCO 12,000-14,000, product # 132 700) tube, and the membrane tube was dialyzed against distilled water. . About 16 hours after the start of dialysis a thin electronic sheet was formed along the membrane tube surface. The membrane tube was then transferred to tertiary distilled water and the membrane tube was twisted to obtain an electronic sheet in water. The electronic sheet has a network structure composed of a bioadhesive and conductive carbon nanotubes, and thus may serve as an interface reinforcing layer when coated on an active material including a carbon material .

The electronic sheet obtained in water was lifted with carbon fiber coated with a positive electrode active material, and then dried in air to form an interfacial reinforcing film. 14A and 14B are views in which a bioadhesive based interfacial reinforcement film is coated on a cathode active material coated on a conductive fiber, and it can be seen that the cathode active material does not easily come off.

Example  4. Fibrous  Electrode Energy  For increased density Fibrous  Electrode Pressing  fair

The electrode fiber coated with the active material and the separator on the carbon fiber was passed through a roll press device. At least one portion of the upper or lower roll of the roll press apparatus has a form stacked with an elastic material (eg, rubber), which has an effect of uniform pressure dispersion and minimization of breakdown of the fiber electrode. 15A and 15B show cross sections of electrode fibers before and after pressing. Although the pressing pressure applied in this embodiment was approximately 100 N, the pressure is not an absolute value and may vary depending on the manufacturing conditions of the electrode chamber. 16A and 16B are diagrams showing charge and discharge improvement characteristics of the anode fibrous electrode structure before and after the pressing process is applied, respectively.

In the above described a preferred embodiment according to the present invention with reference to the drawings and embodiments, but this is only exemplary, those skilled in the art that various modifications and equivalent other embodiments are possible from this. You will understand. Therefore, the protection scope of the present invention should be defined by the appended claims.

Claims (22)

Conductive fibers comprising a carbon component; An active material layer covering an outer surface of the conductive fiber; And A separator formed on the active material layer; Separation membrane integrated fibrous electrode structure comprising a. The method of claim 1, A bioadhesive is introduced between the conductive fiber and the active material layer, between the active material layer and the separator, and at least one of the inside of the active material layer, The bioadhesive is a fibrous electrode structure comprising a phage on which a peptide having a binding ability to a carbon material is displayed. The method of claim 1, The conductive fiber comprising the carbon component includes at least one of a conductive carbon fiber, a carbon component-containing conductive polymer fiber, and a carbon component-containing conductive metal fiber. The method of claim 3, The conductive metal fiber is a fibrous electrode structure is a fiber made of SUS, Al, Cu, Ni or a combination thereof. The method of claim 1, The active material layer is a fibrous electrode structure comprising a composite of the active material and the graticule material. The method of claim 1, The active material layer is LiCoO ₂ , LiNiO ₂ , LiMn ₂ O ₄ , LiCoPO ₄ , LiFePO ₄ , LiMnPO _{4 ,} LiNi _x Mn _y Co _z O ₂ (where 0≤x≤1, 0≤y≤1, 0≤z ≦ 1, provided that x + y + z = 1), FeF ₃ , BiF ₃ , BiOF, FeOF polyimide (PI), quinone, and at least one selected from the group consisting of pyromellitic dimide Fibrous electrode structure. The method of claim 1, The active material layer is carbon, Si, SiO ₂ , SnO ₂ , Co ₃ O ₄ , Li ₄ Ti ₅ O ₁₂ (LTO), MoS ₂ , activated carbon, graphene, doped graphene, carbon nanotubes, and modified carbon A fibrous electrode structure comprising at least one selected from the group consisting of nanotubes. The method of claim 1, The separator is a fibrous electrode structure comprising an electrolyte. The method of claim 8, The electrolyte is a fibrous electrode structure in which lithium salt is dissolved. The method of claim 2, Wherein said phage is a phage that has been genetically engineered to have a binding capacity to a carbon material. The method of claim 2, The bio adhesive is a fibrous electrode structure having a sheet form. The method of claim 11, The inner structure of the sheet is a fibrous electrode structure having a percolated network (percolated network) structure. The method of claim 2, The gripping electrode is a fibrous electrode structure (filamentous). A fibrous battery comprising the membrane-integrated fibrous electrode structure according to any one of claims 1 to 13. An anode comprising a membrane-integrated fibrous electrode structure according to any one of claims 1 to 13; And at least one cathode electrode comprising the membrane integrated fibrous electrode structure according to any one of claims 1 to 12, The positive electrode and the negative electrode is twisted, overlapping or woven each other fibrous battery. The method of claim 15, The fibrous battery is a lithium secondary battery fibrous battery. Providing a conductive fiber comprising a carbon component; Forming an active material layer on an outer surface of the conductive fiber; And Forming a separator on an outer surface of the active material layer; Method for producing a membrane-integrated fibrous electrode structure comprising a, The method of claim 17, Introducing a bioadhesive comprising a phage having a peptide having a binding capacity to a carbon material between the conductive fiber and the active material layer, between the active material layer and the separator, and at least one of the inside of the active material layer. The manufacturing method of the fibrous electrode structure made. The method of claim 17, A method for producing a fibrous electrode structure in which the bioadhesive is introduced between the conductive fiber and the active material layer by coating the conductive fiber using a solution obtained by dispersing the bioadhesive in a solvent. The method of claim 17, A method for producing a fibrous electrode structure in which the bioadhesive is introduced into the active material layer by dispersing the bioadhesive together in a composition for forming the active material layer. The method of claim 17, The forming of the active material layer and the forming of the separator may include a continuous process of continuously passing conductive fibers through the active material-containing container and the separator-containing container. The method of claim 17, Method of producing a fibrous electrode structure further comprising the step of pressing after forming the separator.

Images