Liquid composition, method for producing electrode, electrode for electrochemical device, electrode for all-solid-state electrochemical device, electrochemical device, electrical equipment, mobile body, and vehicle

Abstract

To provide a liquid composition capable of forming a coating film having excellent bending resistance and cutting resistance by a liquid discharge method.SOLUTION: A liquid composition comprises: at least one of an active material and a solid electrolyte; a resin that is a triblock copolymer represented by general formula (1) in the figure; and a solvent. (In general formula (1): R1, R3 and R5 each represent a linear or branched alkyl group; R2, R4 and R6 each represent a hydrogen atom or alkyl group; x represents an integer of 10 or more; y represents an integer of 10 or more; and z represents an integer of 10 or more.)SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a liquid composition, a method for producing an electrode, an electrode for an electrochemical device, an electrode for an all-solid-state electrochemical device, an electrochemical device, an electric device, a mobile body, and a vehicle. [Background technology]

[0002] Demand for electrochemical elements, including lithium-ion secondary batteries, is expanding as they are installed in mobile devices, hybrid vehicles, electric vehicles, etc. In addition, there is a growing need for thin batteries to be installed in various wearable devices and medical patches, and the requirements for electrochemical elements are diversifying.

[0003] A liquid composition for an electrode mixture layer used to manufacture an electrode constituting an electrochemical element generally contains an active material, a dispersion medium, and a binder for obtaining the binding property of the resulting electrode mixture layer. In addition to the use of a polymer as the binder, the liquid composition for an electrode mixture layer is prepared at a high solids concentration from the viewpoint of improving productivity, so that the viscosity is 10 3 mPa·s~10 4 The slurry has an extremely high viscosity of mPa·s. Therefore, conventionally, in a method for manufacturing an electrode constituting an electrochemical element, an electrode mixture layer is formed on an electrode substrate by applying a liquid composition for an electrode mixture layer using, for example, a die coater, a comma coater, a reverse roll coater, etc. Alternatively, the electrode mixture layer is formed by screen-printing the liquid composition for an electrode mixture layer on the electrode substrate.

[0004] However, in order to screen print in a shape that meets needs, a plate needs to be prepared for each need. Therefore, a method of forming an electrode mixture layer by discharging a liquid composition for the electrode mixture layer onto an electrode substrate using a liquid discharge device has been investigated (see, for example, Patent Documents 1 and 2). Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a liquid composition capable of forming a coating film having excellent flex resistance and cut resistance. [Means for solving the problem]

[0006] The liquid composition of the present invention as a means for solving the problems comprises: At least one of an active material and a solid electrolyte; A resin that is a triblock copolymer represented by the following general formula (1), and a solvent. [ka] (R in the general formula (1) 1 , R 3 , R 5 represents a linear or branched alkyl group, and R 2 , R 4 , R 6 represents a hydrogen atom or an alkyl group, x represents an integer of 10 or more, y represents an integer of 10 or more, and z represents an integer of 10 or more. [Effects of the Invention]

[0007] According to the present invention, a liquid composition capable of forming a coating film having excellent bending resistance and cutting resistance can be provided. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view showing an example of a positive electrode according to one embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram showing an example of a positive electrode manufacturing apparatus according to one embodiment of the present invention. [Figure 3] FIG. 3 is a schematic diagram showing another example of a positive electrode manufacturing apparatus according to one embodiment of the present invention. [Figure 4] FIG. 4 is a schematic diagram showing a modified example of the liquid ejection device according to the embodiment of the present invention shown in FIGS. [Figure 5A]FIG. 5A is a cross-sectional view showing an example of a negative electrode according to one embodiment of the present invention. [Figure 5B] FIG. 5B is a schematic cross-sectional view showing an electrode for an electrochemical device according to one embodiment of the present invention. [Figure 5C] FIG. 5C is a schematic cross-sectional view showing an electrode stack according to one embodiment of the present invention. [Figure 5D] FIG. 5D is a schematic cross-sectional view showing an electrode stack according to another embodiment of the present invention. [Figure 5E] FIG. 5E is a schematic cross-sectional view showing an electrode stack according to still another embodiment of the present invention. [Figure 6] FIG. 6 is a cross-sectional view showing an example of an electrode element constituting an electrochemical device according to one embodiment of the present invention. [Figure 7] FIG. 7 is a cross-sectional view showing an example of an electrochemical device according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] A liquid composition to be ejected by a conventional liquid ejection method is formed from, for example, an active material, a conductive aid, a binder, as well as a dispersant, a solvent, etc. necessary for stably maintaining the liquid composition to be ejected. However, the addition of dispersants and binders may cause deterioration of the electrochemical properties of the device, so it is desirable to reduce their amounts, and it is particularly required that even a small amount of binder be used to maintain the strength of the film against peeling, bending, or cutting. In particular, when the film is made thicker to increase capacity, the bending resistance becomes very poor, and peeling and cracking of the film occur due to stress, and peeling and cracking from the cross section occur easily due to the impact of cutting. Furthermore, in obtaining a liquid composition that can be ejected by a liquid ejection method, it is also important to improve the degree of freedom in the selection of materials such as dispersion media from the viewpoints of reducing environmental load and optimizing processes. In particular, there has been a desire to reduce the use of NMP solvent, which is commonly used in the production of lithium-ion secondary batteries, and to find alternatives. Furthermore, in order to improve the safety of lithium-ion secondary batteries, the emergence of all-solid-state batteries using solid electrolytes instead of flammable liquid electrolytes is desired. Among solid electrolytes, sulfide-based solid electrolytes, which have particularly high ionic conductivity and excellent properties, generate hydrogen sulfide when in contact with protic solvents and are known to decompose in highly polar solvents such as NMP. Therefore, when preparing a sulfide-based solid electrolyte slurry, it is necessary to use a low-polarity aprotic solvent that does not damage the electrolyte.

[0010] The liquid composition of the present invention can fully resolve various concerns in the prior art, and more specifically, can form a coating film having excellent resistance to bending and cutting.

[0011] The present invention will be described in detail below.

[0012] (liquid composition) In one embodiment of the present invention, the liquid composition contains at least one of an active material and a solid electrolyte, a resin made of a (meth)acrylic acid ester polymer that is a block copolymer, and a solvent, and the resin is dissolved in the solvent. Furthermore, a first aspect of the liquid composition of the present invention is a liquid composition used for forming components of an electrochemical element by a liquid discharge method, which contains at least one of an active material and a solid electrolyte, a resin, and a solvent, wherein the resin is made of a (meth)acrylic acid ester polymer that is a block copolymer, and the resin is dissolved in a non-aqueous solvent. The liquid composition according to one embodiment of the present invention can form at least one of an electrode mixture layer and a solid electrolyte layer. When the liquid composition is a liquid composition for forming an electrode mixture layer, it contains an active material. When the liquid composition is a liquid composition for forming a solid electrolyte layer, it contains a solid electrolyte. The liquid composition can be suitably used as a liquid composition for inkjet ejection. By performing an electrode formation process in which the liquid composition is ejected by inkjet, openings can be formed in the electrode mixture layer due to the high degree of application control.

[0013] <Resin> The resin used in the liquid composition in one embodiment of the present invention is a triblock copolymer represented by the following general formula (1): In the present invention, the (meth)acrylic acid ester polymer refers to either or both of an acrylate and a methacrylate. [ka] (R in the general formula (1) 1 , R 3 , R 5 represents a linear or branched alkyl group, and R 2 , R 4 , R 6 represents a hydrogen atom or an alkyl group, x represents an integer of 10 or more, y represents an integer of 10 or more, and z represents an integer of 10 or more.

[0014] R in the general formula (1) 2 , R 4 and R 6 is preferably a hydrogen atom or a methyl group. 2 and R 4 is a methyl group, and R 6 is more preferably a hydrogen atom. In the general formula (1), x represents an integer of 10 or more, preferably an integer of 50 or more, and more preferably an integer of 100 or more. Furthermore, x is preferably an integer of 3,000 or less, and more preferably an integer of 1,000 or less. In the general formula (1), y represents an integer of 10 or more, preferably an integer of 50 or more, and more preferably an integer of 100 or more. Furthermore, x is preferably an integer of 3,000 or less, and more preferably an integer of 1,000 or less. In the general formula (1), z represents an integer of 10 or more, preferably an integer of 50 or more, and more preferably an integer of 100 or more. Furthermore, x is preferably an integer of 3,000 or less, and more preferably an integer of 1,000 or less.

[0015] The resin is a block copolymer having acrylate and methacrylate represented by general formula (1) as structural units. The block copolymer represented by general formula (1) is preferably a block copolymer having a first (meth)acrylate and a second (meth)acrylate having a lower glass transition point as structural units. The glass transition temperatures of the blocks at both ends of the triblock copolymer represented by general formula (1) are preferably higher than the glass transition temperatures of the blocks sandwiched between the blocks at both ends. In the block copolymer having acrylate and methacrylate as structural units represented by general formula (1), the inclusion of a block composed of methacrylate makes it possible to separate and simultaneously provide two functions: improving the strength of the coating film, and improving the bending resistance, by including a flock composed of acrylate. In addition, when the block of the block polymer represented by general formula (1) is a block copolymer having, as structural unit blocks, a first (meth)acrylate and a second (meth)acrylate represented by general formula (1) having a lower glass transition point, it becomes possible to separate and simultaneously have the function of improving the strength of the coating film by using the first (meth)acrylate as one of the structural unit blocks, and the function of improving the flexural resistance by using the second (meth)acrylate as one of the structural unit blocks. In this case, the glass transition temperature of the first (meth)acrylate and the second (meth)acrylate can be made different from each other by using R 1 , R 3 , R 5 For example, R of the first (meth)acrylate may be different. 1 , R 3 or R 5 The number of carbon atoms in the second methacrylate is 1 , R 3 or R 5 or the number of carbon atoms in the first methacrylate R 1 , R 3 or R 5 The number of carbon atoms in the second methacrylate is 1 , R 3 or R 5The number of carbon atoms in R of the first methacrylate is the same. 1 , R 3 or R 5 is linear, and the R of the second methacrylate 1 , R 3 or R 5 The R of the first methacrylate can be made branched. 1 , R 3 or R 5 The number of carbon atoms in the second methacrylate is 1 , R 3 or R 5 When the number of carbon atoms of is increased, the difference in the number of carbon atoms is preferably 10 or more in order to allow each to exert its respective functions. In addition, as a method for changing the glass transition temperature of each block, 2 , R 4 or R 6 is an acrylate block where R is a hydrogen atom. 2 , R 4 or R 6 The glass transition temperature of the block is lower than that of a methacrylate block in which the alkyl group is alkyl.

[0016] The resin is preferably soluble in a solvent, which will be described later, so that the resin can be uniformly distributed in the coating film, thereby forming a coating film having excellent bending resistance and cutting resistance. Specifically, the term "dissolved" means that 5% by mass of the resin is added to the solvent, dissolved, and then allowed to stand for 10 minutes. If no sediment or supernatant is observed, or if particle size distribution measurement reveals no particulate matter, the resin can be determined to be dissolved.

[0017] R in the general formula (I) 1 , R 3 and R 5 The linear or branched alkyl group is not particularly limited and can be appropriately selected depending on the purpose. For example, from the viewpoint of coating film strength, an alkyl group having 1 to 30 carbon atoms is preferred, and an alkyl group having 1 to 18 carbon atoms is more preferred. R in the general formula (I) 2 , R 4 and R 6 The alkyl group of R 1 However, a methyl group or a hydrogen atom is preferred because raw materials are readily available, and a methyl group is more preferred from the viewpoint of coating film strength.

[0018] The alkyl group is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, an isobutyl group, a pentyl group, a hexyl group, a heptyl group, an ethylhexyl group, an octyl group, a decyl group, a dodecyl group, a 2-butyloctyl group, and an octadecyl group. Among these, methyl, ethyl, isopropyl, n-propyl, tert-butyl, isobutyl, and n-butyl groups are preferred because they maintain fluidity even at room temperature and can form a coating film with high strength.

[0019] The molecular weight of the triblock copolymer is not particularly limited and can be appropriately selected depending on the purpose, but is preferably from 1,000 to 1,000,000, and more preferably from 2,000 to 500,000. The molecular weight is a weight average molecular weight calculated as polystyrene by GPC. When the molecular weight is 1,000 or more, the occurrence of cracks is suppressed and excellent film-forming properties are achieved. When the molecular weight is 1,000,000 or less, the solubility in common organic solvents is good, and the viscosity of the liquid composition is such that it can be ejected by an inkjet method.

[0020] When the resin is a triblock copolymer, the glass transition temperatures of the terminal blocks are preferably higher than the glass transition temperature of the middle block, which allows the resin to have both excellent flexibility and mechanical strength.

[0021] The block copolymer can be synthesized by radical polymerization or the like using a conventionally known method, or can be used as a commercially available product. The commercially available product is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include Kuraray Co., Ltd.'s Clarity LA4285, LA2270, LA2250, LA2140, LA2330, LA3320, LA3710, and LK9243. By using the block copolymer as a binder, it is possible to produce a coating film having excellent flex resistance and binding properties, and further to provide a liquid composition that does not adversely affect the sulfide solid electrolyte.

[0022] <Solvent> The solvent is not particularly limited and can be appropriately selected depending on the purpose, but a non-aqueous solvent is preferred. The non-aqueous solvent refers to an organic solvent having a water content of 1% by mass or less. The solvent is not particularly limited as long as it dissolves the resin, and can be appropriately selected depending on the purpose. From the viewpoint of the solubility of the binder and the dispersibility of the conductive additive, for example, aromatic hydrocarbons such as toluene, xylene, mesitylene, anisole, and phenetole; hydrocarbon solvents such as hexane, heptane, nonane, octane, decane, menthane, cyclohexane, cyclooctane, and p-menthane; ethyl butyrate, ethyl valerate, ethyl hexanoate, ethyl heptanoate, ethyl octanoate, ethyl nonanoate, ethyl decanoate, ethyl undecanoate, ethyl laurate, and methyl butyrate; Examples of suitable solvents include ester-based solvents such as ethyl acetate, methyl valerate, methyl hexanoate, methyl heptanoate, methyl octanoate, methyl nonanoate, methyl decanoate, methyl undecanoate, methyl laurate, ethyl isovalerate, isoamyl acetate, isobutyl isobutyrate, methyl 3-methoxyisobutyrate, butyl isobutyrate, isobutyl isovalerate, butyl 2-methylbutyrate, butyl isovalerate, heptyl acetate, isoamyl isovalerate, 2-ethylhexyl acetate, hexyl butyrate, ethyl benzoate, hexyl hexanoate, amyl n-octanoate, and hexyl acetate, as well as amides such as N-methylpyrrolidone. Among these, particularly when using sulfide-based solid electrolytes, aprotic solvents with low polarity are preferred. These solvents may be used alone or in combination of two or more.

[0023] <Active material> As the active material, a positive electrode active material or a negative electrode active material that can be applied to an electrochemical element can be used.

[0024] The positive electrode active material is not particularly limited as long as it is capable of reversibly absorbing and releasing alkali metal ions, and alkali metal-containing transition metal compounds can be used.

[0025] Examples of alkali metal-containing transition metal compounds include lithium-containing transition metal compounds such as composite oxides containing lithium and one or more elements selected from the group consisting of cobalt, manganese, nickel, chromium, iron, and vanadium.

[0026] Examples of lithium-containing transition metal compounds include lithium cobalt oxide, lithium nickel oxide, and lithium manganese oxide.

[0027] As the alkali metal-containing transition metal compound, a polyanionic compound having an XO4 tetrahedron (X=P, S, As, Mo, W, Si, etc.) in its crystal structure can also be used. Among these, lithium-containing transition metal phosphate compounds such as lithium iron phosphate and lithium vanadium phosphate are preferred in terms of cycle characteristics, and lithium vanadium phosphate is particularly preferred in terms of the lithium diffusion coefficient and the input / output characteristics of the electrochemical device.

[0028] From the viewpoint of electron conductivity, the polyanionic compound is preferably composited by coating the surface with a conductive aid such as a carbon material.

[0029] The negative electrode active material is not particularly limited as long as it is capable of reversibly absorbing and releasing alkali metal ions, but carbon materials containing graphite having a graphite-type crystal structure can be used.

[0030] Examples of carbon materials include natural graphite, artificial graphite, non-graphitizable carbon (hard carbon), and easily graphitizable carbon (soft carbon).

[0031] Examples of negative electrode active materials other than carbon materials include lithium titanate and titanium oxide.

[0032] In terms of the energy density of the electrochemical device, it is preferable to use a high-capacity material such as silicon, tin, a silicon alloy, a tin alloy, silicon oxide, silicon nitride, or tin oxide as the negative electrode active material.

[0033] When the active material contains lithium, the solvent is preferably a non-aqueous solvent. In this case, the water content in the liquid composition is preferably 5% by mass or less, more preferably 1% by mass or less. When the water content in the liquid composition is 5% by mass or less, the lithium contained in the active material reacts with water to form compounds such as lithium carbonate, which can prevent a decrease in the discharge capacity of the electrochemical device. Furthermore, the decomposition of compounds such as lithium carbonate during charging and discharging of the electrochemical device can be prevented, which can prevent gas generation.

[0034] The mode diameter of the active material is preferably 3 μm or less, more preferably 1 μm or less When the mode diameter of the active material is 3 μm or less, the ejection stability and storage stability of the liquid composition are improved.

[0035] Cumulative 10% volume particle diameter of the active material (D 10 ) is preferably 0.1 μm or more, more preferably 0.15 μm or more. 10 When the particle size is 0.1 μm or more, the storage stability of the liquid composition of this embodiment is improved.

[0036] The content of the active material in the liquid composition is preferably 10% by mass or more, and more preferably 15% by mass or more. When the content of the active material in the liquid composition is 10% by mass or more, the number of printing cycles required to form an electrode mixture layer with a predetermined basis weight is reduced. The polymer of the present invention has good solubility in solvents, and therefore it is possible to increase the solid content concentration of the ink.

[0037] <Solid electrolyte> A material for forming a solid electrolyte layer can be used as the electrolyte. The material for forming the solid electrolyte layer is not particularly limited as long as it is a solid substance that has electronic insulation properties and ion conductivity, but sulfide solid electrolytes and oxide solid electrolytes are preferred from the viewpoint of high ionic conductivity. Examples of sulfide solid electrolytes include Li 10 GeP2S 12Alternatively, Li6PS5X (X is F, Cl, Br, or I) having an argyrodite crystal structure may be mentioned. As the oxide solid electrolyte, for example, LLZ (Li7La3Zr2O 12 ) or LATP(Li) with NASICON-type crystal structure 1+x Al x Ti20 x (PO4)3) (0.1≦x≦0.4), LLT (Li 0.33 La 0.55 TiO3), amorphous LIPON (Li 2.9 PO 3.3 N 0.4 ) etc. These solid electrolytes may be used alone or in combination of two or more. Examples of electrolyte materials that can be dissolved or dispersed in a liquid to form these solid electrolyte layers include Li2S, P2S5, and LiCl, which are precursors of solid electrolytes, and Li2S-PS5-based glass and Li7P3S, which are materials for solid electrolytes. 11 Glass ceramics and the like. Furthermore, a material for forming a gel electrolyte layer can also be used as the electrolyte. The gel electrolyte is not particularly limited as long as it exhibits ion conductivity. For example, polymers that form the network structure of the gel electrolyte include polyethylene oxide, polypropylene oxide, polyacrylonitrile, polymethyl methacrylate, polyvinyl chloride, copolymers of vinylidene fluoride and propylene hexafluoride, and polyethylene carbonate. The solvent molecules held in the gel electrolyte include ionic liquids such as methyl-1-propylpyrrolidinium bis(fluorosulfonylimide), 1-butyl-1-methylpyrrolidinium bis(fluorosulfonylimide), 1-methyl-1-propylpiperidinium bis(fluorosulfonylimide), 1-ethyl-3-methylimidazolium bis(fluorosulfonylimide), 1-methyl-3-propylimidazolium bis(fluorosulfonylimide), and N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis(fluorosulfonyl)imide. Alternatively, a mixture of a liquid such as tetraglyme, propylene carbonate, fluoroethylene carbonate, ethylene carbonate, or diethyl carbonate with a lithium salt may be used. The lithium salt is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include lithium hexafluorophosphate (LiPF), lithium borofluoride (LiBF), lithium hexafluoride (LiAsF), lithium trifluoromethasulfonate (LiCFSO), lithium bis(trifluoromethylsulfonyl)imide (LiN(CFSO)), lithium bis(pentafluoroethylsulfonyl)imide (LiN(CFSO)), etc. These gel electrolytes may be used alone or in combination of two or more. The electrolyte material dissolved or dispersed in the liquid to form these gel electrolyte layers may be a solution of the above-mentioned polymer compound and an ionic liquid or a lithium salt. Alternatively, the electrolyte material dissolved or dispersed in the liquid may be a precursor of the gel electrolyte (for example, a combination of polyethylene oxide or polypropylene oxide having acrylate groups at both ends with a solution of an ionic liquid or a lithium salt). When using these solid electrolytes or gel electrolytes, they can be used as a liquid composition together with the active material.

[0038] <Other ingredients> Examples of other components include dispersants, conductive additives, insulating materials, and electrolyte materials.

[0039] -Dispersant- The dispersant is not particularly limited as long as it can improve the dispersibility of the active material in the liquid composition, and examples thereof include polymer dispersants such as polyethylene oxides, polypropylene oxides, polycarboxylic acids, naphthalenesulfonic acid formalin condensation compounds, polyethylene glycols, polycarboxylic acid partial alkyl esters, polyethers, and polyalkylene polyamines; low molecular weight dispersants such as alkyl sulfonic acids, quaternary ammonium higher alcohol alkylene oxides, polyhydric alcohol esters, and alkyl polyamines; and inorganic dispersants such as polyphosphate dispersants. The dispersants may be used alone or in combination of two or more. Furthermore, when the liquid composition contains a solid electrolyte, the dispersant is not particularly limited as long as it dissolves in the dispersion medium, does not react with the solid electrolyte, and can disperse the inorganic solid electrolyte, and conventionally known or commercially available dispersants can be appropriately selected depending on the purpose. The dispersant may be used alone or in combination of two or more.

[0040] In this specification, the dispersant being dissolved in the dispersion medium means that the dispersant is compatible with the dispersion medium. More specifically, when 3% by mass of the dispersant is added to the dispersion medium, the dispersant is dissolved, and the mixture is allowed to stand for 10 minutes. If no precipitate or supernatant is observed, the dispersant can be determined to be dissolved.

[0041] The content of the dispersant in the liquid composition is not particularly limited and can be appropriately selected depending on the purpose. However, if the solid content concentration of the dispersant is too high, aggregation may occur. Therefore, the solid content concentration of the dispersant is preferably 10% by mass or less, and more preferably 3% by mass or less, of the total amount of the active material or solid electrolyte to be dispersed.

[0042] -Conductive additive- As the conductive assistant, for example, carbon materials such as conductive carbon black, carbon nanofibers, carbon nanotubes, graphene, and graphite particles can be used. The conductive additive may be previously compounded with the active material.

[0043] The conductive carbon black can be produced by, for example, a furnace method, an acetylene method, a gasification method, or the like.

[0044] As the conductive additive other than the carbon material, metal particles such as aluminum particles and metal fibers can be used.

[0045] The mass ratio of the conductive additive to the active material is preferably 10% by mass or less, and more preferably 8% by mass or less. When the mass ratio of the conductive additive to the active material is 10% by mass or less, the storage stability of the liquid composition of this embodiment is improved.

[0046] The viscosity of the liquid composition at 25° C. is preferably 200 mPa·s or less, and more preferably 100 mPa·s or less. When the viscosity of the liquid composition at 25° C. is 200 mPa·s or less, the ejection stability of the liquid composition is improved. The lower limit of the viscosity of the liquid composition at 25° C. is not particularly limited, and is the viscosity of the solvent alone. The viscosity of the liquid composition can be measured, for example, using a Brookfield viscometer at a rotation speed of ≦100 rpm and a temperature of 25°C.

[0047] The liquid composition of one embodiment of the present invention can be produced by dispersing at least one of an active material and a solid electrolyte, a resin, and, if necessary, a dispersant in a solvent. At this time, the resin, which is a block copolymer made of a (meth)acrylic acid ester polymer, is dissolved in the dispersion medium. The block copolymer has good solubility in the solvent, so it is dissolved in the dispersion medium. This has the advantage of being able to be produced at significantly lower cost than when the block copolymer is present in the ink as particles. Whether or not the solution has dissolved can be determined by, for example, whether or not a precipitate is visually confirmed when centrifuged at 10,000 rpm for 10 minutes.

[0048] The liquid composition can be used to manufacture electrodes for electrochemical devices. The electrochemical element is not particularly limited as long as it is capable of storing electricity, and examples thereof include a battery and a capacitor.

[0049] <Method of producing liquid composition> The liquid composition can be produced by dissolving or dispersing the above-mentioned components in the above-mentioned solvent. Specifically, the liquid composition can be prepared by mixing the above components with the above solvent using a mixer such as a ball mill, a sand mill, a bead mill, a pigment disperser, a crusher, an ultrasonic disperser, a homogenizer, a planetary mixer, or a Filmix.

[0050] (Electrode manufacturing method) The method for producing an electrode of the present invention includes a step of discharging the liquid composition of the present invention onto an electrode substrate, and may further include other steps as necessary. The method for producing an electrode preferably further includes a step of pressurizing the electrode substrate onto which the liquid composition has been discharged, which makes it difficult for the components constituting the electrode mixture layer to peel off, thereby improving the reliability of the electrochemical device.

[0051] The method for applying the liquid composition is not particularly limited, and examples thereof include liquid ejection methods such as inkjet printing, spray coating, and dispenser printing; spin coating, casting, microgravure coating, gravure coating, bar coating, roll coating, wire bar coating, dip coating, slit coating, capillary coating, nozzle coating, gravure printing, screen printing, flexographic printing, offset printing, and reverse printing. Among these, the inkjet method is particularly preferred. The inkjet method allows electrodes to be produced in any shape without contact. This results in advantages such as reduced loss of active material due to die-cutting during the electrode production process. In this case, the liquid composition may be applied to only one side of the current collector or to both sides. The thickness of the liquid composition on the current collector after application and before drying can be appropriately set depending on the thickness of the electrode mixture layer obtained by drying.

[0052] The method for drying the liquid composition on the electrode substrate is not particularly limited and any known method can be used, including, for example, drying with warm air, hot air, or low-humidity air, vacuum drying, and drying by irradiation with infrared rays or electron beams, etc. By drying the liquid composition on the electrode substrate in this manner, an electrode mixture layer can be formed on the electrode substrate, and an electrode comprising the electrode substrate and the electrode mixture layer can be obtained.

[0053] There are no particular limitations on the material that constitutes the electrode substrate (current collector), as long as it is conductive and stable against the applied potential.

[0054] <Positive electrode> FIG. 1 shows an example of the positive electrode used in the present invention. Positive electrode 10 has positive electrode substrate 11 and positive electrode mixture layer 12 formed on one surface thereof, the positive electrode mixture layer 12 containing a positive electrode active material and / or a solid electrolyte, and the polymer. Positive electrode mixture layer 12 may be formed on both sides of positive electrode substrate 11 .

[0055] The shape of the positive electrode 10 is not particularly limited, and examples thereof include a flat plate shape.

[0056] Examples of materials that can be used to form the positive electrode substrate 11 include stainless steel, nickel, aluminum, and copper.

[0057] <Positive electrode manufacturing method> FIG. 2 shows an example of a method for producing the positive electrode used in the present invention.

[0058] The method for producing the positive electrode 10 includes a step of ejecting the liquid composition 12A onto the positive electrode substrate 11 using the liquid ejection device 300. Here, the liquid composition 12A contains a positive electrode active material and / or a solid electrolyte, the polymer, and a solvent.

[0059] The liquid composition 12 A is stored in a tank 307 and is supplied from the tank 307 to a liquid ejection head 306 via a tube 308 .

[0060] Furthermore, the liquid ejection device 300 may be provided with a mechanism for capping the nozzle to prevent the liquid composition 12A from drying out when it is not being ejected from the liquid ejection head 306.

[0061] When manufacturing the positive electrode 10, the positive electrode substrate 11 is placed on a heatable stage 400, droplets of the liquid composition 12A are ejected onto the positive electrode substrate 11, and then the positive electrode substrate 11 is heated. At this time, the stage 400 or the liquid ejection head 306 may be moved.

[0062] Furthermore, when the liquid composition 12A discharged onto the positive electrode substrate 11 is heated, it may be heated by the stage 400 or by a heating mechanism other than the stage 400.

[0063] The heating mechanism is not particularly limited as long as it does not come into direct contact with the liquid composition 12A, and examples thereof include a resistance heater, an infrared heater, a fan heater, etc. Note that a plurality of heating mechanisms may be installed.

[0064] The heating temperature is not particularly limited as long as it is a temperature at which the solvent can be volatilized, and is preferably in the range of 70°C to 150°C from the viewpoint of power consumption.

[0065] Furthermore, when the liquid composition 12A discharged onto the positive electrode substrate 11 is heated, ultraviolet light may be irradiated thereto.

[0066] FIG. 3 shows another example of the method for producing a positive electrode according to the present invention. The method for producing the positive electrode 10 includes a step of ejecting the liquid composition 12A onto the positive electrode substrate 11 using the liquid ejection device 300.

[0067] First, an elongated positive electrode substrate 11 is prepared. The positive electrode substrate 11 is then wound around a cylindrical core and set on a feed roller 304 and a take-up roller 305 so that the side on which the positive electrode composite layer 12 is to be formed faces upward in FIG. 3 . The feed roller 304 and the take-up roller 305 rotate counterclockwise, and the positive electrode substrate 11 is transported from right to left in FIG. 3 . Then, droplets of liquid composition 12A are ejected onto the transported positive electrode substrate 11 from a liquid ejection head 306 installed above the positive electrode substrate 11 between the feed roller 304 and the take-up roller 305. The droplets of liquid composition 12A are ejected so as to cover at least a portion of the positive electrode substrate 11.

[0068] A plurality of liquid ejection heads 306 may be installed in a direction substantially parallel to or substantially perpendicular to the direction in which the positive electrode substrate 11 is transported.

[0069] Next, positive electrode substrate 11 onto which liquid composition 12A has been ejected is transported to heating mechanism 309 by delivery roller 304 and take-up roller 305. As a result, the solvent contained in liquid composition 12A on positive electrode substrate 11 volatilizes, forming positive electrode composite layer 12 and obtaining positive electrode 10. Thereafter, positive electrode 10 is cut to a desired size by punching or the like.

[0070] The heating mechanism 309 is not particularly limited as long as it does not come into direct contact with the liquid composition 12A, and examples thereof include a resistance heater, an infrared heater, and a fan heater.

[0071] The heating mechanism 309 may be installed either above or below the positive electrode substrate 11, or a plurality of heating mechanisms may be installed.

[0072] The heating temperature is not particularly limited as long as it is a temperature at which the solvent can be volatilized, and is preferably in the range of 70°C to 150°C from the viewpoint of power consumption.

[0073] Furthermore, when the liquid composition 12A discharged onto the positive electrode substrate 11 is heated, ultraviolet light may be irradiated thereto.

[0074] FIG. 4 shows a modified example of the liquid ejection device 300. As shown in FIG. The liquid ejection device 300 ′ is capable of circulating the liquid composition 12 A through the liquid ejection head 306 , the tank 307 and the tube 308 by controlling the pump 310 and the valves 311 and 312 .

[0075] In addition, the liquid ejection device 300' is provided with an external tank 313, and when the liquid composition 12A in the tank 307 decreases, it is possible to supply the liquid composition 12A from the external tank 313 to the tank 307 by controlling the pump 310 and the valves 311, 312, and 314.

[0076] By using the liquid ejection devices 300 and 300', it is possible to eject the liquid composition 12A onto a targeted location on the positive electrode substrate 11. Furthermore, by using the liquid ejection devices 300 and 300', it is possible to bond the contacting surfaces of the positive electrode substrate 11 and the positive electrode mixture layer 12 together. Furthermore, by using the liquid ejection devices 300 and 300', it is possible to make the thickness of the positive electrode mixture layer 12 uniform.

[0077] <Negative electrode> FIG. 5A shows an example of the negative electrode used in the present invention. Negative electrode 20 has a negative electrode mixture layer 22 containing a negative electrode active material formed on one surface of a negative electrode substrate 21. Note that negative electrode mixture layer 22 may be formed on both surfaces of negative electrode substrate 21.

[0078] The shape of the negative electrode 20 is not particularly limited, and may be, for example, a flat plate shape.

[0079] Examples of materials that can be used to form the negative electrode substrate 21 include stainless steel, aluminum, titanium, and tantalum.

[0080] <Method of manufacturing the negative electrode> The method for producing the negative electrode 20 is the same as the method for producing the positive electrode 10, except that the liquid composition is discharged onto the negative electrode substrate 21. Here, the liquid composition contains a negative electrode active material and a solvent.

[0081] 5B is a schematic cross-sectional view showing an electrode for an electrochemical device according to one embodiment of the present invention. The electrode for an electrochemical device 25 has a first substrate 21, a first electrode mixture layer 20 disposed on the first substrate 21, and an insulating resin layer 10 disposed on the outer periphery of the first electrode mixture layer 20. Note that Figure 5B illustrates a configuration in which an electrode composite layer 20 and an insulating resin layer 10 are provided on one side of the first base 21, but the electrode composite layer 20 and the insulating resin layer 10 may also be provided on both opposing sides of the first base 21.

[0082] Fig. 5C is a schematic cross-sectional view showing an electrode laminate according to one embodiment of the present invention. Fig. 5D is a schematic cross-sectional view showing an electrode laminate according to another embodiment of the present invention. Fig. 5E is a schematic cross-sectional view showing an electrode laminate according to yet another embodiment of the present invention. The electrode laminate 35 has a first base 21, a first electrode mixture layer 20 disposed on the first base 21, an insulating resin layer 10 disposed on the outer periphery of the first electrode mixture layer 20, and a solid electrolyte layer 30 disposed on the first electrode mixture layer 20 and the insulating resin layer 10. 5C to 5E show a configuration in which the electrode mixture layer 20, the insulating resin layer 10, and the solid electrolyte layer 30 are provided on one side of the first base 21, but the electrode mixture layer 20, the insulating resin layer 10, and the solid electrolyte layer 30 may be provided on both opposing sides of the first base 21. Furthermore, as shown in FIG. 5D, an adhesive layer 22 containing a metal that alloys with lithium may be provided between the substrate and the electrode mixture layer.

[0083] <Base> The substrate is not particularly limited as long as it has electron conductivity and is stable to an applied potential, and can be appropriately selected depending on the purpose. Examples include aluminum foil, copper foil, stainless steel foil, titanium foil, etched foil obtained by etching these foils to form fine holes, carbon-coated foil whose surface is coated with a carbon-containing resin layer, and perforated substrates used in lithium ion capacitors.

[0084] <Electrode composite layer> The electrode mixture layer (hereinafter sometimes referred to as "active material layer") is not particularly limited and can be appropriately selected depending on the purpose. For example, it may contain an active material (negative electrode active material or positive electrode active material), and may further contain a conductive aid, a binder, a dispersant, a solid electrolyte, and other components as necessary. When the solid electrolyte layer is a sulfide solid electrolyte layer, the cured product (insulating resin layer) of the liquid composition of the present invention can suppress deterioration of the ionic conductivity of the sulfide solid electrolyte layer. Therefore, the electrode for electrochemical devices or the electrode mixture layer in the electrode laminate preferably contains an active material and a sulfide solid electrolyte.

[0085] The electrode mixture layer may have openings 23 as shown in FIG. 5E. The number of openings 23 is preferably one or more, and more preferably two or more. The openings 23 may penetrate the electrode mixture layer from the surface of the electrode mixture layer to the surface of the substrate, or may not penetrate all the way to the surface of the substrate. The opening 23 may be hollow or may be filled with the material 24. When the opening 23 is filled with the material 24, the material 24 may be a single type or a mixture of two or more types, but in either case, the material 24 is different in quality (compound or composition) from the material that constitutes the electrode mixture layer. From the viewpoint of improving ion conductivity, the material 24 is preferably a material having a solid electrolyte contained in the solid electrolyte layer, and more preferably a material having the same composition as the solid electrolyte layer. The electrode mixture layer having the openings 23 can be suitably produced by using inkjet as the electrode mixture layer forming means, since application control is easy.

[0086] (Method of manufacturing an electrochemical element) The method for producing an electrochemical device of the present invention includes the steps of the method for producing an electrode of the present invention, and may further include other steps as necessary.

[0087] <Electrode element> FIG. 6 shows an example of an electrode element constituting the electrochemical device of the present invention. The electrode element 40 is formed by laminating a positive electrode 15 and a negative electrode 25 with a separator 30 interposed therebetween. The negative electrodes 25 are laminated on both sides of the positive electrode 15. A lead wire 41 is connected to the positive electrode substrate 11, and a lead wire 42 is connected to the negative electrode substrate 21.

[0088] Positive electrode 15 is similar to positive electrode 10 except that positive electrode mixture layers 12 are formed on both sides of positive electrode substrate 11 .

[0089] Negative electrode 25 is similar to negative electrode 20 except that negative electrode mixture layers 22 are formed on both sides of negative electrode substrate 21 . There is no particular limit to the number of stacked positive electrodes 15 and negative electrodes 25 of the electrode element 40.

[0090] Furthermore, the number of positive electrodes 15 and the number of negative electrodes 25 in the electrode element 40 may be the same or different.

[0091] <Separator> The separator 30 is provided between the positive electrode 15 and the negative electrode 25 to prevent short-circuiting between the positive electrode 15 and the negative electrode 25 .

[0092] Examples of the separator 30 include paper such as kraft paper, vinylon-mixed paper, and synthetic pulp-mixed paper, cellophane, polyethylene graft membrane, polyolefin nonwoven fabric such as polypropylene melt-blown nonwoven fabric, polyamide nonwoven fabric, glass fiber nonwoven fabric, and micropore membrane.

[0093] There is no particular limitation on the size of the separator 30 as long as it can be used in an electrochemical element. The separator 30 may have a single layer structure or a laminated structure. When a solid electrolyte is used, the separator 30 can be omitted.

[0094] <Electrochemical element> FIG. 7 shows a secondary battery as an example of the electrochemical device of the present invention.

[0095] In the secondary battery 1, an electrolyte layer 51 is formed by injecting an aqueous electrolyte solution or a non-aqueous electrolyte into the electrode element 40, and the secondary battery 1 is sealed with an exterior case 52. In the secondary battery 1, the lead wires 41 and 42 are drawn out to the outside of the exterior case 52.

[0096] The secondary battery 1 may include other components as necessary. The secondary battery 1 is not particularly limited, and examples thereof include a lithium ion secondary battery.

[0097] The shape of the secondary battery 1 is not particularly limited, and examples thereof include a laminate type, a cylinder type in which a sheet electrode and a separator are spirally wound, a cylinder type with an inside-out structure in which a pellet electrode and a separator are combined, and a coin type in which a pellet electrode and a separator are stacked.

[0098] <Aqueous electrolyte solution> Examples of electrolyte salts that constitute the aqueous electrolyte solution include sodium hydroxide, potassium hydroxide, sodium chloride, potassium chloride, ammonium chloride, zinc chloride, zinc acetate, zinc bromide, zinc iodide, zinc tartrate, and zinc perchloride.

[0099] <Non-aqueous electrolyte> As the non-aqueous electrolyte, a solid electrolyte or a non-aqueous electrolytic solution can be used. Here, the non-aqueous electrolyte is an electrolyte in which an electrolyte salt is dissolved in a non-aqueous solvent.

[0100] -Non-aqueous solvent- The non-aqueous solvent is not particularly limited and can be appropriately selected depending on the purpose, but it is preferable to use, for example, an aprotic organic solvent.

[0101] As the aprotic organic solvent, for example, a carbonate-based organic solvent such as a chain carbonate, a cyclic carbonate, etc. Among these, a chain carbonate is preferred because of its high dissolving power for the electrolyte salt. In addition, it is preferable that the aprotic organic solvent has a low viscosity.

[0102] Examples of the chain carbonate include dimethyl carbonate (DMC), diethyl carbonate (DEC), and methyl ethyl carbonate (EMC).

[0103] The content of the chain carbonate in the non-aqueous solvent is preferably 50% by mass or more. When the content of the chain carbonate in the non-aqueous solvent is 50% by mass or more, even if the non-aqueous solvent other than the chain carbonate is a cyclic substance with a high dielectric constant (e.g., a cyclic carbonate or a cyclic ester), the content of the cyclic substance is reduced. Therefore, even if a non-aqueous electrolyte solution with a high concentration of 2 mol / L (M) or more is prepared, the viscosity of the non-aqueous electrolyte solution is reduced, and the non-aqueous electrolyte solution penetrates into the electrodes and ions diffuse well.

[0104] Examples of cyclic carbonates include propylene carbonate (PC), ethylene carbonate (EC), butylene carbonate (BC), and vinylene carbonate (VC).

[0105] Examples of non-aqueous solvents other than carbonate organic solvents include ester organic solvents such as cyclic esters and chain esters, and ether organic solvents such as cyclic ethers and chain ethers.

[0106] Examples of cyclic esters include γ-butyrolactone (γBL), 2-methyl-γ-butyrolactone, acetyl-γ-butyrolactone, and γ-valerolactone.

[0107] Examples of chain esters include alkyl propionates, dialkyl malonates, alkyl acetates (e.g., methyl acetate (MA), ethyl acetate), and alkyl formates (e.g., methyl formate (MF), ethyl formate).

[0108] Examples of cyclic ethers include tetrahydrofuran, alkyltetrahydrofuran, alkoxytetrahydrofuran, dialkoxytetrahydrofuran, 1,3-dioxolane, alkyl-1,3-dioxolane, and 1,4-dioxolane.

[0109] Examples of the chain ether include 1,2-dimethoxyethane (DME), diethyl ether, ethylene glycol dialkyl ether, and diethylene glycol dialkyl ether ether.

[0110] <Electrolyte salt> There are no particular limitations on the electrolyte salt, as long as it has high ionic conductivity and is soluble in a non-aqueous solvent. The electrolyte salt preferably contains a halogen atom.

[0111] Examples of cations constituting the electrolyte salt include lithium ions.

[0112] Examples of anions that constitute the electrolyte salt include BF4 - , PF6 - , AsF6 - , CF3SO3 - , (CF3SO2)2N - , (C2F5SO2)2N - Examples include:

[0113] The lithium salt is not particularly limited and can be appropriately selected depending on the purpose. Examples include lithium hexafluorophosphate (LiPF), lithium borofluoride (LiBF), lithium hexafluoride (LiAsF), lithium trifluoromethasulfonate (LiCFSO), lithium bis(trifluoromethylsulfonyl)imide (LiN(CFSO)), and lithium bis(pentafluoroethylsulfonyl)imide (LiN(CFSO)). These may be used alone or in combination of two or more. Among these, LiPF is preferred from the viewpoint of ionic conductivity, and LiBF is preferred from the viewpoint of stability. The electrolyte salt may be used alone or in combination of two or more.

[0114] The concentration of the electrolyte salt in the nonaqueous electrolytic solution can be appropriately selected depending on the purpose, but if the nonaqueous electrochemical device is of a swing type, it is preferably 1 mol / L to 2 mol / L, and if the nonaqueous electrochemical device is of a reserve type, it is preferably 2 mol / L to 4 mol / L.

[0115] The use of the electrochemical element is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include mobile objects such as vehicles, smartphones, notebook computers, pen-input personal computers, mobile personal computers, electronic book players, mobile phones, mobile fax machines, mobile copiers, mobile printers, headphone stereos, video movie players, LCD televisions, handheld vacuum cleaners, portable CDs, minidiscs, transceivers, electronic organizers, calculators, memory cards, portable tape recorders, radios, backup power supplies, motors, lighting equipment, toys, game devices, clocks, strobe lights, cameras, and other electrical equipment. Of these, vehicles and electrical equipment are preferred. Examples of mobile objects include standard automobiles, large special purpose automobiles, small special purpose automobiles, trucks, large motorcycles, and standard motorcycles.

[0116] Here, an embodiment of a moving body that is an electrochemical element according to the present invention will be described with reference to the drawings, although the present invention is not limited to these embodiments.

[0117] [Moving object] FIG. 17 is a schematic diagram showing an example of a moving body that is an electrochemical device according to one embodiment of the present invention. The moving object 70 is, for example, an electric vehicle. The moving object 70 includes a motor 71, an electrochemical device 72, and wheels 73.

[0118] The electrochemical element 72 is an electrochemical element according to the present invention. The electrochemical element 72 supplies power to the motor 71 to drive the motor 71. The driven motor 71 can drive the wheels 73, and as a result, the mobile object 70 can move. Since the moving body 70 is equipped with an electrochemical element 72, short circuits between the positive and negative electrodes are prevented, and the moving body can be driven by power from the electrochemical element, which has excellent battery characteristics, allowing it to move safely and efficiently.

[0119] The mobile object 70 is not limited to an electric vehicle, but may also be a PHEV, HEV, or a locomotive or motorcycle that can run using a diesel engine and an electrochemical device in combination. Furthermore, the mobile object 70 may be a transport robot used in a factory or the like that can run using only an electrochemical device or a combination of an engine and an electrochemical device. Furthermore, the mobile object 70 may be an object that does not move as a whole, but only a part of it, such as an assembly robot that is arranged on a factory production line and that can operate an arm or the like using only an electrochemical device or a combination of an engine and an electrochemical device. [Example]

[0120] Examples of the present invention will be described below, but the present invention is not limited to these examples in any way.

[0121] (Synthesis Examples 1 to 7) <Synthesis of (methyl methacrylate-block-n-butyl acrylate-block-methyl methacrylate) triblock copolymer> According to the method described in WO2002 / 026847, methyl methacrylate-block-n-butyl acrylate-block-methyl methacrylate triblock polymers (P-1) to (P-7) shown in Table 1 below were obtained by living anionic polymerization. The Mw of the methyl methacrylate block shown in Table 1 is the difference between the Mw of the obtained block polymer and the molecular weight of n-butyl acrylate, and represents the sum of the Mw of the two polymethyl methacrylate blocks formed at both ends of polyn-butyl acrylate.

[0122] [Table 1]

[0123] (Synthesis Examples 8-10) Polymers (P-8) to (P-11) shown in Table 2 were obtained in the same manner as in Synthesis Example 1-7.

[0124] [Table 2]

[0125] (Synthesis Example 11) <Synthesis of (n-butyl acrylate-block-methyl methacrylate) block copolymer (Comparative Example 1)> 2.23 parts by mass of cuprous bromide (CuBr; manufactured by Wako Pure Chemical Industries, Ltd.), 1.04 parts by mass of diethyl 2,5-dibromoadipate (DBADE; manufactured by Tokyo Chemical Industry Co., Ltd.), 85.14 parts by mass of n-butyl acrylate (BA; manufactured by Tokyo Chemical Industry Co., Ltd.), and 15.64 parts by mass of acetonitrile (ACN; manufactured by Tokyo Chemical Industry Co., Ltd.) were charged, and the temperature was raised to 80°C while nitrogen was passed through the mixture. Next, a mixture of 0.35 parts by mass of N,N,N',N',N''-pentamethyldiethylenetriamine (PMDETA; manufactured by Wako Pure Chemical Industries, Ltd.) as an initiator and 2.00 parts by mass of ACN was added, and the polymerization reaction was carried out until the weight-average molecular weight (Mw) measured by GPC reached approximately 25,000. The reaction solution was filtered through activated alumina to remove catalyst residue, and then the remaining monomer and solvent were removed under reduced pressure at 80°C for approximately 2 hours, yielding a polybutyl acrylate polymer block with a weight-average molecular weight of 25,200. 50 parts by mass of the obtained polymer block, 1.3 parts by mass of cuprous bromide (CuBr; manufactured by Wako Pure Chemical Industries, Ltd.), 50 parts of methyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.), and 20 parts of toluene as a polymerization solvent were mixed and heated to 80°C while stirring and passing nitrogen through. Next, a mixed solution of 0.1 parts by mass of PMDETA as an initiator and 2.3 parts by mass of toluene was added, and a polymerization reaction was carried out at 80° C. until the weight average molecular weight reached about 50,000, after which the catalyst was similarly removed. The resulting reaction solution was poured into a large amount of methanol, and the precipitate was removed by decantation. The polymer was then purified by reprecipitation three times. The product was dried under reduced pressure at 80°C to obtain a polymer with Mw = 49,400. Filtration and drying yielded a (n-butyl acrylate-block-methyl methacrylate) block copolymer with a theoretical copolymerization ratio of n-butyl acrylate and methyl methacrylate of 50:50 in terms of mass ratio.

[0126] (Synthesis Example 12) <Synthesis of (n-butyl acrylate-block-methyl methacrylate) block copolymer (compound 2)> 2.23 parts by mass of cuprous bromide (CuBr; manufactured by Wako Pure Chemical Industries, Ltd.), 1.04 parts by mass of diethyl 2,5-dibromoadipate (DBADE; manufactured by Tokyo Chemical Industry Co., Ltd.), 102.17 parts by mass of n-butyl acrylate (BA; manufactured by Tokyo Chemical Industry Co., Ltd.), and 15.64 parts by mass of acetonitrile (ACN; manufactured by Tokyo Chemical Industry Co., Ltd.) were charged, and the temperature was raised to 80°C while nitrogen was passed through the mixture. Next, a mixture of 0.35 parts by mass of N,N,N',N',N''-pentamethyldiethylenetriamine (PMDETA; manufactured by Wako Pure Chemical Industries, Ltd.) as an initiator and 2.00 parts by mass of ACN was added, and the polymerization reaction was carried out until the weight-average molecular weight (Mw) reached approximately 30,000 as measured by GPC. The reaction solution was filtered through activated alumina to remove catalyst residue, and then the remaining monomer and solvent were removed under reduced pressure at 80°C for approximately 2 hours, yielding a polybutyl acrylate polymer block with a weight-average molecular weight of 29,800. 78 parts by mass of the obtained polymer block, 1.3 parts by mass of cuprous bromide (CuBr; manufactured by Wako Pure Chemical Industries, Ltd.), 35 parts by mass of methyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.), and 20 parts by mass of toluene as a polymerization solvent were mixed and heated to 80°C while stirring and passing nitrogen through. Next, a mixed liquid of 0.1 parts by mass of PMDETA as an initiator and 2.3 parts of toluene was added, and a polymerization reaction was carried out at 80° C. until the weight average molecular weight reached about 50,000, and the catalyst was similarly removed. The resulting reaction solution was poured into a large amount of methanol, and the precipitate was removed by decantation. The polymer was then purified by reprecipitation three times. The product was dried under reduced pressure at 80°C to obtain a polymer with Mw = 50,200. Filtration and drying yielded a (n-butyl acrylate-block-methyl methacrylate) block copolymer with a theoretical copolymerization ratio of n-butyl acrylate and methyl methacrylate of 60:40 in terms of mass ratio.

[0127] (Synthesis Example 13) In the same manner as in Synthesis Examples 1 and 2, a (n-butyl acrylate-block-methyl methacrylate) block copolymer (composition 3) having a Mw of 54,000 and a theoretical copolymerization ratio of n-butyl acrylate and methyl methacrylate of 70:30 in terms of substance amount ratio was synthesized. (Synthesis Examples 14 to 17) A 200 mL flask was charged with 30 mL of degassed toluene and heated to 80°C. A mixture consisting of 30 g of each monomer and 2,2'-azobis(2,4-dimethylvaleronitrile) (1 mol% relative to the monomer) was added dropwise over one hour, and after the addition was complete, the mixture was stirred at 80°C for six hours. After cooling to room temperature, the reaction solution was added dropwise to methanol, and the precipitate was recovered by decantation and dried in vacuo to obtain the following polymers (comparison-4) to (comparison-7) (random copolymers for copolymers). The subscripts in parentheses for copolymers indicate the ratio of the constituent components.

[0128] [ka] (ratio-4)

[0129] [ka] (ratio-5)

[0130] [ka] (ratio-6)

[0131] [ka] (ratio-7)

[0132] Example 1 <Preparation of Positive Electrode Liquid Composition> A liquid composition for a positive electrode was obtained by treating a mixture of 5 parts by weight of resin (P-1), 100 parts by weight of nickel-based positive electrode active material (hereinafter sometimes referred to as "NCM") (manufactured by Toshima Manufacturing Co., Ltd.), 5 parts by weight of acetylene black, 2.5 parts by weight of dispersant Solsperse 13940 (manufactured by Lubrizol Japan Co., Ltd.), and 39 parts by weight of methyl hexanoate with an ultrasonic homogenizer. At this time, resin (P-1) was dissolved in the mixture.

[0133] <Manufacturing positive electrodes for secondary batteries> The liquid composition for a positive electrode obtained above was applied to a 20 μm-thick aluminum foil current collector using an applicator, and the coating was then dried in an oven at 120° C. to obtain a positive electrode for a secondary battery in which a positive electrode layer was formed on the current collector. The coating was performed so that the average thickness of the positive electrode mixture layer was 80 μm.

[0134] Example 2 A positive electrode for a secondary battery was formed in the same manner as in Example 1, except that the resin (P-1) in Example 1 was changed to (P-2).

[0135] Example 3 A positive electrode for a secondary battery was formed in the same manner as in Example 1, except that the resin (P-1) in Example 1 was changed to (P-3).

[0136] Example 4 A positive electrode for a secondary battery was formed in the same manner as in Example 1, except that the resin (P-1) in Example 1 was changed to (P-4).

[0137] Example 5 A positive electrode for a secondary battery was formed in the same manner as in Example 1, except that the resin (P-1) in Example 1 was changed to (P-5).

[0138] Example 6 A positive electrode for a secondary battery was formed in the same manner as in Example 1, except that the resin (P-1) in Example 1 was changed to (P-6).

[0139] Example 7 A positive electrode for a secondary battery was formed in the same manner as in Example 1, except that the resin (P-1) in Example 1 was changed to (P-7).

[0140] Example 8 A positive electrode for a secondary battery was formed in the same manner as in Example 1, except that the resin (P-1) in Example 1 was changed to (P-8).

[0141] Example 9 A positive electrode for a secondary battery was formed in the same manner as in Example 1, except that the resin (P-1) in Example 1 was changed to (P-9).

[0142] Example 10 A positive electrode for a secondary battery was formed in the same manner as in Example 1, except that the resin (P-1) in Example 1 was changed to (P-10).

[0143] Example 11 A positive electrode for a secondary battery was formed in the same manner as in Example 1, except that the resin (P-1) in Example 1 was changed to (P-11).

[0144] Example 12 <Preparation of Liquid Composition for Solid Electrolyte> A liquid composition containing a solid electrolyte was prepared using the argyrodite-type sulfide solid electrolyte Li6PS5Cl (LPSC) synthesized according to the published literature, "J. Power Sources. 2018, 396, 33-40." The solvent used was anisole (Tokyo Chemical Industry Co., Ltd.), which had been dehydrated with molecular sieves 3A to a concentration of 20 ppm or less using a Karl Fischer moisture analyzer. A mixture of 150 parts by weight of this solvent, 100 parts by weight of the synthesized sulfide solid electrolyte, 1 part by weight of a dispersant (Lubrizol Solsperse 21000), and 5 parts by weight of a resin (P-6) was treated with an ultrasonic homogenizer to obtain a liquid composition for a solid electrolyte.

[0145] <Manufacturing of solid electrolyte layer> The liquid composition for a solid electrolyte obtained above was applied to a 20 μm-thick aluminum foil current collector using an applicator, and the coating was then dried in an oven at 120° C. to obtain an electrode having a solid electrolyte layer formed on the current collector.

[0146] Example 13 An electrode was formed in the same manner as in Example 12, except that the resin (P-6) in Example 12 was changed to (P-8).

[0147] Example 14 An electrode was formed in the same manner as in Example 12, except that the resin (P-6) in Example 12 was changed to (P-9).

[0148] Example 15 An electrode was formed in the same manner as in Example 12, except that the resin (P-6) in Example 12 was changed to (P-10).

[0149] (Comparative Example 1) A positive electrode for a secondary battery was formed in the same manner as in Example 1, except that the resin (P-1) in Example 1 was changed to (Ratio-1).

[0150] (Comparative Example 2) A positive electrode for a secondary battery was formed in the same manner as in Example 1, except that the resin (P-1) in Example 1 was changed to (Ratio-2).

[0151] (Comparative Example 3) A positive electrode for a secondary battery was formed in the same manner as in Example 1, except that the resin (P-1) in Example 1 was changed to (Comparative-3).

[0152] Comparative Example 4 A positive electrode for a secondary battery was formed in the same manner as in Example 1, except that the resin (P-1) in Example 1 was changed to (Ratio-4).

[0153] (Comparative Example 5) A positive electrode for a secondary battery was formed in the same manner as in Example 1, except that the resin (P-1) in Example 1 was changed to (Ratio-5).

[0154] (Comparative Example 6) A positive electrode for a secondary battery was formed in the same manner as in Example 1, except that the resin (P-1) in Example 1 was changed to (Ratio-6).

[0155] (Comparative Example 7) A positive electrode for a secondary battery was formed in the same manner as in Example 1, except that the resin (P-1) in Example 1 was changed to (Ratio-7).

[0156] For Examples 1 to 14 and Comparative Examples 1 to 7, the cutting resistance and bending resistance of the coating film of the positive electrode layer or solid electrolyte layer coated on the current collector foil were measured by the following methods.

[0157] <Cutting resistance> The positive electrode layer or solid electrolyte layer coated on the current collector foil in Examples 1 to 14 and Comparative Examples 1 to 7 was cut into a rectangle 50 mm long and 30 mm wide using a Thomson blade. The cut surface was visually inspected for chipping and peeling, and the cutting resistance was evaluated based on the following evaluation criteria. The results are shown in Table 3. [Evaluation criteria] ○: No chipping or peeling. △: Chips or peeling of less than 1 mm, no chips or peeling of 1 mm or more. ×: Chips or peeling of 1 mm or more.

[0158] <Bending resistance> The positive electrode layer or solid electrolyte layer coated on the current collector foil in Examples 1 to 14 and Comparative Examples 1 to 7 was cut with a Thomson blade to obtain rectangular test pieces measuring 50 mm in length and 30 mm in width. The obtained test pieces were wrapped around cylindrical metal rods of different diameters and visually inspected for cracks in the coating film and peeling from the metal substrate. The minimum diameter at which cracks or peeling occurred was measured using a cylindrical mandrel bending tester (manufactured by Cortec Co., Ltd.) equipped with a cylindrical mandrel, and the bending resistance was evaluated based on the following evaluation criteria. The results are shown in Table 3. The bending resistance can be measured using a method conforming to ISO 1519. [Evaluation criteria] ◎: Minimum diameter is less than 0.5 ○: Minimum diameter is 0.5 or more and less than 10.0 ×: Minimum diameter is 10.0 or more

[0159] [Table 3]

[0160] The results in Table 3 show that the positive electrode membranes produced from the positive electrode liquid compositions prepared in Examples 1 to 11 and the solid electrolyte membranes produced from the solid electrolyte liquid compositions prepared in Examples 12 to 15 all exhibited good results in both cut resistance and flex resistance. In comparison, the positive electrode membranes produced from the positive electrode liquid compositions prepared in Comparative Examples 1 to 7 were brittle membranes with poor cut resistance and flex resistance. Therefore, it can be seen that the liquid compositions of the Examples, which are examples of the present invention, are suitable for use as liquid compositions for producing active material layers, electrolyte layers, and the like.

[0161] The embodiments of the present invention are as follows, for example. <1> At least one of an active material and a solid electrolyte; A resin that is a triblock copolymer represented by the following general formula (1), and a solvent. [ka] (R in the general formula (1) 1 , R 3 , R 5 represents a linear or branched alkyl group, and R 2 , R 4 , R 6 represents a hydrogen atom or an alkyl group, x represents an integer of 10 or more, y represents an integer of 10 or more, and z represents an integer of 10 or more. <2> R in the general formula (1) 2 , R 4 , R 6 is a hydrogen atom or a methyl group, <1> The liquid composition according to claim 1. <3> R in the general formula (1) 2 and R 4 is a methyl group, and R6 is a hydrogen atom; <1> The liquid composition according to claim 1. <4> The linear or branched alkyl group in the general formula (1) is any one selected from the group consisting of a methyl group, an ethyl group, an isopropyl group, an n-propyl group, a tert-butyl group, an isobutyl group, and an n-butyl group. <1> or <2> The liquid composition according to claim 1. <5> the glass transition temperatures of the blocks at both ends of the triblock copolymer are higher than the glass transition temperatures of the blocks sandwiched between the blocks at both ends; <1> or <2> The liquid composition according to claim 1. <6> The molecular weight of the triblock copolymer is 1,000 or more and 1,000,000 or less. <1> or <2> The liquid composition according to claim 1. <7> The active material is at least one selected from a lithium-containing transition metal oxide and a lithium-containing transition metal phosphate compound. <1> or <2> The liquid composition according to any one of the above items. <8> the solvent is a non-aqueous solvent; <1> or <2> The liquid composition according to any one of the above items. <9> On the electrode substrate, <1> or <2> 1. A method for producing an electrode, comprising the step of discharging the liquid composition according to any one of the above items to form a coating film. <10> a substrate; an electrode mixture layer provided on the substrate and containing an active material, The electrode for an electrochemical element is characterized in that the electrode mixture layer contains a resin made of a triblock copolymer represented by the following general formula (1): [ka] <11> a substrate; an electrode mixture layer provided on the substrate and containing an active material; a solid electrolyte layer provided on the electrode mixture layer and containing a solid electrolyte, The electrode for an electrochemical element is characterized in that the electrode mixture layer or the solid electrolyte layer contains a resin made of a triblock copolymer represented by the following general formula (1): [ka] <12> an adhesive layer containing a metal that alloys with lithium is provided between the substrate and the electrode mixture layer; <10> or <11> 1. An electrode for an electrochemical element according to claim 1. <13> The electrode mixture layer has an opening. <10> or <11> 1. An electrode for an electrochemical element according to claim 1. <14> <10> or <11> An electrode for an all-solid-state electrochemical device having the electrode for an electrochemical device according to claim 1, the electrode mixture layer has an opening, The electrode for an all-solid-state electrochemical element is characterized in that the opening contains a sulfide solid electrolyte. <15> <10> or <11> 1. An electrochemical element characterized by having the electrode for an electrochemical element described above. <16> <15> and an electrical device comprising the electrochemical element according to claim 1. <17> <15> A mobile object is characterized by having the electrochemical element described above. <18> <15> A vehicle characterized by having the electrochemical device described above. [Explanation of symbols]

[0162] 1 Secondary battery 10 positive electrode 11 Positive electrode substrate 12 Positive electrode mixture layer 12A Liquid composition 15 Positive electrode 20 negative electrode 21 negative electrode substrate 22 Negative electrode composite layer 25 negative electrode 30 Separator 40 Electrode element 41 Lead Line 42 Lead Line 51 Electrolyte layer 52 Exterior 300 Liquid discharge device 300' liquid dispensing device 306 Liquid ejection head [Prior art documents] [Patent documents]

[0163] [Patent Document 1] JP 2009-152180 A (Patent No. 5571304 A) [Patent Document 2] JP 2010-97946 A (Patent No. 5913780 A)

Claims

1. At least one of an active material and a solid electrolyte; A resin that is a triblock copolymer represented by the following general formula (1), A liquid composition comprising: a solvent. 【Chemical 1】 (R in the general formula (1) １ , R ３ , R ５ represents a linear or branched alkyl group, and R ２ , R ４ , R ６ represents a hydrogen atom or an alkyl group, x represents an integer of 10 or more, y represents an integer of 10 or more, and z represents an integer of 10 or more.

2. R in the general formula (1) ２ , R ４ , R ６ The liquid composition according to claim 1 , wherein is a hydrogen atom or a methyl group.

3. R in the general formula (1) ２ and R ４ is a methyl group, and R ６ The liquid composition of claim 1 , wherein is a hydrogen atom.

4. 3. The liquid composition according to claim 1, wherein the linear or branched alkyl group in the general formula (1) is any one selected from the group consisting of a methyl group, an ethyl group, an isopropyl group, an n-propyl group, a tert-butyl group, an isobutyl group, and an n-butyl group.

5. The liquid composition according to claim 1 or 2, wherein the glass transition temperatures of the blocks at both ends of the triblock copolymer are higher than the glass transition temperatures of the blocks sandwiched between the blocks at both ends.

6. The liquid composition according to claim 1 or 2, wherein the triblock copolymer has a molecular weight of 1,000 or more and 1,000,000 or less.

7. 3. The liquid composition according to claim 1, wherein the active material is at least one selected from the group consisting of a lithium-containing transition metal oxide and a lithium-containing transition metal phosphate compound.

8. The liquid composition according to claim 1 , wherein the solvent is a non-aqueous solvent.

9. A method for producing an electrode, comprising a step of discharging the liquid composition according to claim 1 onto an electrode substrate to form a coating film.

10. a substrate; an electrode mixture layer provided on the substrate and containing an active material, The electrode for an electrochemical element is characterized in that the electrode mixture layer contains a resin made of a triblock copolymer represented by the following general formula (1): 【Chemistry 2】

11. a substrate; an electrode mixture layer provided on the substrate and containing an active material; a solid electrolyte layer provided on the electrode mixture layer and containing a solid electrolyte, An electrode for an electrochemical element, wherein the electrode mixture layer or the solid electrolyte layer contains a resin made of a triblock copolymer represented by the following general formula (1): 【Chemistry 3】

12. 12. The electrode for an electrochemical element according to claim 10, wherein an adhesive layer containing a metal that alloys with lithium is provided between the substrate and the electrode mixture layer.

13. The electrode for an electrochemical element according to claim 10 or 11, wherein the electrode mixture layer has an opening.

14. An electrode for an all-solid-state electrochemical device comprising the electrode for an electrochemical device according to claim 10 or 11, the electrode mixture layer has an opening, The electrode for an all-solid-state electrochemical element, wherein the opening contains a sulfide solid electrolyte.

15. An electrochemical device comprising the electrode for an electrochemical device according to claim 10 or 11.

16. An electrical device comprising the electrochemical element according to claim 15.

17. A mobile object comprising the electrochemical device according to claim 15.

18. A vehicle comprising the electrochemical device according to claim 15.

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