Liquid composition for insulation layer formation, electrode and method for manufacturing the same, electrochemical element, and separator and method for manufacturing the same

Abstract

To provide a liquid composition for insulation layer formation which enables production of an insulation layer excellent in film strength and an electrochemical element excellent in electrochemical characteristics, and is excellent in discharge property and storage stability.SOLUTION: A liquid composition for insulation layer formation contains insulating inorganic particles, a resin containing at least one selected from a structural unit group including structural units represented by the following general formula (1), a resin including a structural unit represented by the following general formula (4), in which R2 is preferably a poloxamer, and a resin containing a fluorine atom. The resin containing the fluorine atom preferably contains at least one fluorine resin selected from PVDF, PVDF-HFP, PTFE, and PEVE. General formula (4): R3-R2-R4.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a liquid composition for forming an insulating layer, an electrode and a method for producing the same, an electrochemical device, and a separator and a method for producing the same. [Background technology]

[0002] Electrochemical devices such as lithium-ion secondary batteries exhibit high energy density and are therefore expected to be used as high-capacity power sources for electric vehicles, etc. In recent years, separators in electrochemical devices have become thinner in order to improve volumetric energy density, but this has also led to demands for greater safety.

[0003] For the purpose of ensuring safety, the development of integrated electrodes having a structure in which an insulating particle layer is formed on an electrode mixture layer is progressing. For example, a technology has been proposed in which a porous protective film is formed on the surface of the active material layer of a positive or negative electrode by applying a mixture containing electrically insulating ceramic powder particles and a binder resistant to the electrolyte solution to the surface of the active material layer (see, for example, Patent Document 1). Furthermore, a non-aqueous electrolyte secondary battery has been proposed that has an insulating layer provided adjacent to the positive electrode active material layer on another part of the surface of the positive electrode current collector, and has a specified thermal shrinkage rate, in order to prevent a short circuit between the positive electrode current collector and the negative electrode active material layer even when the battery generates heat (see, for example, Patent Document 2). Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a liquid composition for forming an insulating layer, which can provide an insulating layer having excellent film strength and an electrochemical device having excellent electrochemical properties, and which has excellent dischargeability and storage stability. [Means for solving the problem]

[0005] The liquid composition for forming an insulating layer of the present invention as a means for solving the above problems comprises: insulating inorganic particles; a resin containing at least one selected from a structural unit represented by general formula (1), a structural unit represented by general formula (2), and a structural unit represented by general formula (3); A resin containing a structural unit represented by general formula (4), A liquid composition for forming an insulating layer, comprising: the content of the resin containing at least one selected from the structural unit represented by general formula (1), the structural unit represented by general formula (2), and the structural unit represented by general formula (3) is 1 mass % or more and 10 mass % or less with respect to the total amount of the insulating inorganic particles; The content of the resin containing the structural unit represented by general formula (4) is 0.1 mass % or more and 5 mass % or less with respect to the total amount of the insulating inorganic particles, The content of the resin containing fluorine atoms is 1% by mass or more and 8% by mass or less with respect to the total amount of the insulating inorganic particles.

[0006] [ka]

[0007] [ka]

[0008] [ka]

[0009] [ka] (In the general formulas (1) to (4), * represents a bonding site to an adjacent main chain structural unit; R2 represents at least one selected from polyurethane, polyester, polyethylene oxide, polypropylene oxide, poloxamer, polycarbonate, silicone, polybutadiene, and hydrogenated polybutadiene butane; R3 and R4 represent a hydroxyl group or an amino group; M represents an ammonium salt; and n, m, and l represent integers of 2 to 500.) [Effects of the Invention]

[0010] According to the present invention, it is possible to obtain an insulating layer having excellent film strength and an electrochemical device having excellent electrochemical properties, and it is also possible to provide a liquid composition for forming an insulating layer that has excellent ejection properties and storage stability. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram showing an electrode according to one embodiment of the present invention. [Figure 2A] FIG. 2A is a schematic cross-sectional view taken along line AA′ in FIG. [Figure 2B] FIG. 2B is a schematic cross-sectional view showing an electrode according to another embodiment of the present invention. [Figure 2C] FIG. 2C is a schematic cross-sectional view showing an electrode according to another embodiment of the present invention. [Figure 3A] FIG. 3A is a schematic cross-sectional view showing an electrode according to another embodiment of the present invention. [Figure 3B] FIG. 3B is a schematic cross-sectional view showing an electrode according to another embodiment of the present invention. [Figure 4] FIG. 4 is a schematic diagram showing an insulating layer on an electrode according to one embodiment of the present invention. [Figure 5] FIG. 5 is a schematic diagram showing an insulating layer on an electrode according to another embodiment of the present invention. [Figure 6] FIG. 6 is a schematic cross-sectional view showing an example of an electrode obtained by the step of drying the insulating layer-forming liquid composition of the present invention. [Figure 7] FIG. 7 is a schematic diagram showing an electrode manufacturing apparatus according to one embodiment of the present invention. [Figure 8] FIG. 8 is a schematic diagram showing an electrochemical device according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] From the viewpoint of improving the volumetric energy density of the electrochemical element, it is preferable that the insulating layer provided adjacent to the electrode mixture layer is applied thinly and uniformly on the substrate to be coated. Therefore, the insulating layer-forming liquid composition that forms the insulating particle layer needs to contain insulating inorganic particles at a high concentration and have a low viscosity.

[0013] In the electric double layer capacitor separator described in Patent Document 1, a polymer binder is dissolved in the liquid composition for forming an insulating layer in order to provide binding between insulating particles in the insulating layer or between insulating particles and an active material. This results in high viscosity, which raises concerns about the difficulty of applying a thin insulating layer. Furthermore, the liquid composition for forming an insulating layer has low dispersibility, leaving room for improvement in storage stability. Furthermore, when the liquid composition for forming an insulating layer is applied to a porous substrate, the solvent and resin penetrate the composition, reducing the binding strength of the resulting insulating layer and, accordingly, reducing film strength.

[0014] In the nonaqueous electrolyte secondary battery described in Patent Document 2, polymer binder particles are dispersed in the liquid composition for forming an insulating layer, so the dispersibility of the liquid composition for forming an insulating layer is low, and there is room for improvement in storage stability. Furthermore, if the amount of polymer binder particles added is kept to a level that does not affect the battery characteristics, sufficient film strength cannot be obtained, and there is a concern that the insulating layer may be damaged.

[0015] The insulating layer-forming liquid composition of the present invention can sufficiently resolve various concerns in the prior art. More specifically, it can provide an insulating layer having excellent film strength and an electrochemical device having excellent electrochemical properties, and can also realize an insulating layer-forming liquid composition having excellent ejection properties and storage stability.

[0016] The present invention will be described in detail below.

[0017] (Liquid composition for forming insulating layer) The liquid composition for forming an insulating layer of the present invention contains insulating inorganic particles, a resin containing at least one selected from the group consisting of a structural unit represented by general formula (1), a structural unit represented by general formula (2), and a structural unit represented by general formula (3), a resin containing a structural unit represented by general formula (4), and a resin containing a fluorine atom, and may contain a solvent and other components as necessary.

[0018] [ka]

[0019] [ka]

[0020] [ka]

[0021] [ka] (In the general formulas (1) to (4), * represents a bonding site to an adjacent main chain structural unit; R2 represents at least one selected from polyurethane, polyester, polyethylene oxide, polypropylene oxide, poloxamer, polycarbonate, silicone, polybutadiene, and hydrogenated polybutadiene butane; R3 and R4 represent a hydroxyl group or an amino group; M represents an ammonium salt; and n, m, and l represent integers of 2 to 500.) Although the dicarboxyl group or a salt thereof in the structural unit represented by general formula (2) and the structural unit represented by general formula (3) is in the trans configuration, it may also be in the cis configuration.

[0022] In this specification, the "insulating layer-forming liquid composition" may be simply referred to as the "liquid composition." In this specification, "a resin containing at least one selected from the group consisting of a structural unit represented by general formula (1), a structural unit represented by general formula (2), and a structural unit represented by general formula (3)" may also be referred to as "a dispersant containing at least one selected from the group consisting of a structural unit represented by general formula (1), a structural unit represented by general formula (2), and a structural unit represented by general formula (3)", "a dispersant", or "a dispersant for insulating layers". In this specification, the term "resin containing a structural unit represented by general formula (4)" may be referred to as "a crosslinking agent containing a structural unit represented by general formula (4)" or "crosslinking agent". In this specification, the "resin containing fluorine atoms" may also be referred to as a "binder containing fluorine atoms," a "binder," or a "binder for insulating layers."

[0023] <Insulating inorganic particles> In this specification, "insulating" means a material having a volume resistivity of 10 8 That is, the insulating inorganic particles in the present invention have a volume resistivity of 10 8 Refers to inorganic particles with a resistance of Ω·cm or more.

[0024] As insulating inorganic particles, the volume resistivity is 10 8 As long as the resistivity is Ω·cm or more, there are no particular limitations and the material can be appropriately selected depending on the purpose, and examples include aluminum oxide (alumina), boehmite, silica, aluminum nitride, silicon nitride, cordierite, sialic acid, mullite, stearite, yttria, zirconia, silicon carbide, etc. Among these, inorganic oxides are preferred, and from the viewpoint of heat resistance, aluminum oxide and boehmite are more preferred, and α-alumina is even more preferred. Alpha-alumina is known to function as a scavenger for "junk" species, i.e., species that can cause capacity fade in lithium-ion secondary batteries. Furthermore, alumina particles have good wettability and affinity for electrolytes, improving the cycling performance of lithium-ion secondary batteries. The use of alpha-alumina as insulating inorganic particles improves redispersibility and inkjet ejectability in liquid compositions and heat resistance in insulating layers. These insulating inorganic particles may be used alone or in combination of two or more kinds.

[0025] The shape of the insulating inorganic particles is not particularly limited and can be appropriately selected depending on the purpose. Examples include rectangular, spherical, elliptical, cylindrical, oval, dogbone, and amorphous shapes.

[0026] The median diameter of the insulating inorganic particles is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 200 nm or more and 1,000 nm or less. When the insulating inorganic particles have a median diameter of 200 nm or more, the particles can be prevented from floating in the air (generating mist) during inkjet ejection, and in the insulating layer, the insulating inorganic particles can be prevented from adhering to the substrate due to the loss of fine particles. When the median diameter of the insulating inorganic particles is 1,000 nm or less, nozzle clogging during inkjet ejection can be eliminated, improving ejection properties. In addition, in the case of an insulating layer, this is preferable because the thickness of the insulating layer is made uniform and homogenous (with less unevenness).

[0027] The method for measuring the median diameter of insulating inorganic particles is not particularly limited and can be appropriately selected depending on the purpose, and examples include dynamic light scattering / photon correlation spectroscopy, laser diffraction, centrifugal sedimentation, induction diffraction, etc. More specifically, after diluting the liquid composition so that the solid content is 10 mass% or less, the median diameter can be measured using a concentrated particle size analyzer (FPAR-1000, manufactured by Otsuka Electronics Co., Ltd.) or a multi-analyte nanoparticle size measurement system (nanoSAQLA, manufactured by Otsuka Electronics Co., Ltd.).

[0028] The insulating inorganic particles preferably include first insulating inorganic particles having a median diameter of 200 nm or more but less than 1,000 nm and second insulating inorganic particles having an average Stokes diameter of less than 30 nm, where the average Stokes diameter is the average value of the long diameters of the particles measured, for example, by observation with a transmission electron microscope (TEM). When the liquid composition contains second insulating inorganic particles having an average Stokes diameter of less than 30 nm, the energy barrier in the interaction potential energy between particles can be made sufficiently small, and the problem of the inorganic particles not being redispersed even when re-agitated after a long period of standing and causing the inorganic particles to aggregate can be eliminated.

[0029] The content of the insulating inorganic particles is not particularly limited and can be appropriately selected depending on the purpose, but from the viewpoint of achieving a uniform thickness of the insulating layer after drying, it is preferably 10% by mass or more, more preferably 20% by mass or more, based on the total amount of the liquid composition. From the viewpoint of viscosity, it is preferably 60% by mass or less, based on the total amount of the liquid composition, and from the viewpoint of ejectability by inkjet, it is more preferably 55% by mass or less.

[0030] The insulating inorganic particles may be appropriately synthesized or commercially available. Examples of commercially available aluminum oxide insulating inorganic particles include, by trade name, AKP-15, AKP-20, AKP-30, AKP-50, AKP-53, AKP-700, AKP-3000, AA-03, AA-04, AA-05, AA-07, AA-1.5, AKP-G07, and AKP-G15 (high-purity alumina manufactured by Sumitomo Chemical Co., Ltd.), TM-DA, TM-DAR, and TM-5D (manufactured by Taimei Chemical Industry Co., Ltd.), CT-3000LSSG (manufactured by Almatis), LS-502, LS-711CB, and SLS-710 (manufactured by Nippon Light Metal Co., Ltd.), and SEPal-60 and SEPal-70 (manufactured by Alteo). An example of a commercially available product of boehmite as insulating inorganic particles is BMB-07 (Kawai Lime Industry Co., Ltd.).

[0031] <Dispersant> The dispersant in the present invention contains at least one selected from the structural unit represented by general formula (1), the structural unit represented by general formula (2), and the structural unit represented by general formula (3).

[0032] [ka]

[0033] [ka]

[0034] [ka] (In the general formulae (1) to (3), * represents a bonding site to an adjacent main chain structural unit, M represents an ammonium salt, and n, m, and l represent integers of 2 to 500.)

[0035] The acid anhydride group and carboxyl group in the structural units represented by the general formulae (1) to (3) have a repulsive effect between dispersant molecules due to steric hindrance, and therefore, by adding a dispersant having a carboxyl group to a liquid composition, the insulating inorganic particles in the liquid composition can be uniformly dispersed as primary particles and maintained in a dispersed state without re-aggregation for a long period of time, thereby improving storage stability. The acid anhydride group and carboxyl group in the structural units represented by the general formulas (1) to (3) have excellent dispersion stability with the binder for forming the insulating layer, and therefore can reduce the thixotropy of the liquid composition. In addition, the carboxyl group and the acid anhydride group can improve the ejection properties by inkjet printing due to their respective effects.

[0036] There is no particular limitation on n in the general formula (1) and it can be appropriately selected depending on the purpose, but an integer of 10 to 100 is preferable. There is no particular limitation on m in the general formula (2) and it can be appropriately selected depending on the purpose, but it is preferably an integer of 10 to 100. There is no particular limitation on l in the general formula (3) and it can be appropriately selected depending on the purpose, but it is preferably an integer of 10 to 100.

[0037] The method for confirming whether the dispersant in the liquid composition for forming an insulating layer contains the structural units represented by the general formulas (1) to (3) is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a nuclear magnetic resonance (NMR) device and Fourier transform infrared spectroscopy (FT-IR).

[0038] The content of the dispersant in the liquid composition for forming an insulating layer of the present invention is 1% by mass or more and 10% by mass or less, preferably 1.5% by mass or more and 8% by mass or less, and more preferably 2% by mass or more and 6% by mass or less, based on the total amount of the insulating inorganic particles. When the content of the dispersant in the insulating layer-forming liquid composition is 1% by mass or more relative to the total amount of the insulating inorganic particles, the insulating inorganic particles can be sufficiently dispersed and maintained in a dispersed state. This improves storage stability and inkjet ejection properties. Furthermore, the insulating layer obtained has a coating on the surfaces of the insulating inorganic particles, preventing them from falling off the insulating layer. When the content of the dispersant in the insulating layer-forming liquid composition is 10 mass % or less based on the total amount of insulating inorganic particles, the thixotropy can be reduced, and in the resulting insulating layer (electrochemical element), problems such as a decrease in output due to an increase in battery resistance and a decrease in cycle characteristics can be eliminated.

[0039] The molecular weight of the dispersant in the insulating layer-forming liquid composition is not particularly limited and can be appropriately selected depending on the purpose. For example, the number average molecular weight is preferably 1,000 or more and 100,000 or less. When the number average molecular weight of the dispersant in the insulating layer-forming liquid composition is 1,000 or more, the dispersibility of the insulating inorganic particles among themselves improves, and therefore the storage stability also improves. When the number average molecular weight of the dispersant in the insulating layer-forming liquid composition is 100,000 or less, the inkjet ejection properties are excellent. The method for analyzing the molecular weight of the dispersant in the liquid composition for forming an insulating layer is not particularly limited and can be selected appropriately depending on the purpose, but for example, it can be measured by gel permeation chromatography (HLC8320-GPC, manufactured by Shimadzu Corporation).

[0040] The dispersant is preferably dissolved solely in the electrolyte solvent. When the dispersant is dissolved solely in the electrolyte solvent, the resulting insulating layer has good lithium ion conductivity. In this specification, the term "dissolved" refers to a state in which the desired molecules are uniformly mixed in the dispersion medium.

[0041] The electrolyte solvent is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a non-polar solvent and a mixed solution containing a non-polar solvent (mixed solvent). In this specification, a non-polar solvent is a solvent having a bond dipole moment of 1.15 D or less.

[0042] The method for confirming whether the dispersant is dissolved in the electrolyte solvent is not particularly limited and can be appropriately selected depending on the purpose. For example, after dissolving the dispersant in the electrolyte solvent, the particle size distribution is evaluated, and if no distribution occurs, it can be determined that the dispersant is dissolved. If a particle size distribution occurs, it can be determined that the dispersant is dispersed. The solubility of a dispersant in an electrolyte solvent can be confirmed under conditions in which the electrolyte solvent is liquid, for example, by confirming the solubility in dimethyl carbonate, which is used as a non-aqueous electrolyte solvent, at 25°C and 1 atmosphere.

[0043] The dispersant may be a suitably synthesized one or a commercially available one. Examples of commercially available dispersants include Marialim (registered trademark) AAB-0851, Marialim AFB-1521, Marialim AKM-0531, Marialim AWS-0851, Marialim HKM-50A, Marialim HKM-150A, Marialim SC-0708A, Marialim SC-0505K, Marialim SC-1015F, AKM-1511-60 (all manufactured by NOF Corporation), Diakarna (registered trademark) 30M (manufactured by Mitsubishi Chemical Corporation), and ISOBAM (registered trademark)-10 (manufactured by Kuraray Co., Ltd.).

[0044] <Crosslinking agent> The crosslinking agent in the present invention contains a structural unit represented by general formula (4).

[0045] [ka] (In general formula (4), R2 represents at least one selected from polyurethane, polyester, polyethylene oxide, polypropylene oxide, poloxamer, polycarbonate, silicone, polybutadiene, and hydrogenated polybutadiene butane, and R3 and R4 represent a hydroxyl group or an amino group.)

[0046] R2 in general formula (4) may have a repeating unit. In this case, the number of repeating units of R2 is not particularly limited and can be appropriately selected depending on the purpose, but from the viewpoint of suppressing inhibition of crosslinking due to steric hindrance, it is preferably 2 to 100, more preferably 10 to 50.

[0047] R2 in general formula (4) is preferably a poloxamer from the viewpoint of promoting Li-ion conduction. In this specification, the term "poloxamer" refers to a block copolymer made of polyethylene oxide and polypropylene oxide. In terms of facilitating a crosslinking reaction, it is preferable that the number of repeating units of polypropylene oxide is smaller than the number of repeating units of polyethylene oxide in the poloxamer.

[0048] In terms of storage stability, it is preferable that at least one of R3 and R4 in general formula (4) is a hydroxyl group, and it is more preferable that both of R3 and R4 are hydroxyl groups.

[0049] The method for confirming whether the crosslinking agent in the liquid composition for forming an insulating layer contains a structural unit represented by general formula (4) is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a nuclear magnetic resonance (NMR) device and Fourier transform infrared spectroscopy (FT-IR).

[0050] The content of the crosslinking agent in the liquid composition for forming an insulating layer of the present invention is 0.1% by mass or more and 5% by mass or less, preferably 0.3% by mass or more and 4% by mass or less, and more preferably 0.5% by mass or more and 3% by mass or less, based on the total amount of the insulating inorganic particles. When the content of the crosslinking agent in the liquid composition for forming an insulating layer is 0.1 mass % or more relative to the total amount of the insulating inorganic particles, the crosslinked resin obtained by the reaction between the dispersant and the crosslinking agent becomes insufficient, and when the temperature of the obtained electrochemical element rises, the problem of the dispersant and the crosslinking agent leaching out can be eliminated. When the content of the crosslinking agent in the liquid composition for forming an insulating layer is 5 mass % or less relative to the total amount of the insulating inorganic particles, the resulting insulating layer (electrochemical element) can eliminate problems such as a decrease in output due to an increase in battery resistance caused by the resin component and a decrease in cycle characteristics.

[0051] The molecular weight of the crosslinking agent in the insulating layer-forming liquid composition is not particularly limited and can be appropriately selected depending on the purpose. For example, the number average molecular weight is preferably 200 or more and 100,000 or less. When the number average molecular weight of the crosslinking agent in the insulating layer-forming liquid composition is 200 or more, flexibility can be imparted to the structure formed. When the number average molecular weight of the crosslinking agent in the insulating layer-forming liquid composition is 100,000 or less, an increase in viscosity of the liquid composition can be suppressed. The method for analyzing the molecular weight of the crosslinking agent in the liquid composition for forming an insulating layer is not particularly limited and can be selected appropriately depending on the purpose, but for example, it can be measured by gel permeation chromatography (HLC8320-GPC, manufactured by Shimadzu Corporation).

[0052] The crosslinking agent is preferably soluble in the electrolyte solvent alone. When the crosslinking agent is dissolved solely in the electrolyte solvent, the resulting insulating layer (electrochemical element) has good lithium ion conductivity. In this specification, the term "dissolved" refers to a state in which the desired molecules are uniformly mixed in the dispersion medium.

[0053] The method for confirming whether the crosslinking agent is dissolved in the electrolyte solvent is not particularly limited and can be appropriately selected depending on the purpose. For example, after dissolving the crosslinking agent in the electrolyte solvent, the particle size distribution is evaluated, and if no distribution occurs, it can be determined that the crosslinking agent is dissolved. If a particle size distribution occurs, it can be determined that the crosslinking agent is dispersed. The solubility of the crosslinking agent in the electrolyte solvent can be confirmed under conditions where the electrolyte solvent is liquid, for example, by confirming the solubility in dimethyl carbonate, which is used as the non-aqueous electrolyte solvent, at 25°C and 1 atmosphere.

[0054] The crosslinking agent may be an appropriately synthesized one or a commercially available product. Commercially available crosslinking agents include, for example, trade names such as Epan (registered trademark) 740 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., R2: poloxamer), Epan 450 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), Jeffamine ED-2003 (manufactured by Huntsman), Jeffamine D-2000 (manufactured by Huntsman), DBE (registered trademark)-C25 (manufactured by Gelest), DULANOL T5650E (manufactured by Asahi Kasei Corporation), ETERNACOLL (registered trademark)-PH200J (manufactured by Ube Industries, Ltd.), NISSO (registered trademark)-PB-G1000 (manufactured by Nippon Soda Co., Ltd.), PEG200 (manufactured by Tokyo Chemical Industry Co., Ltd.), Uniloop 5TP-300KB (manufactured by NOF Corporation, R2: poloxamer), Nymeen (registered trademark) L207 (manufactured by NOF Corporation), Nymeen DT208 (manufactured by NOF Corporation), and K-FLEX. Examples include UD-320-100 (manufactured by Kings Industries), K-FLEX 148 (manufactured by Kings Industries), and K-FLEX 188 (manufactured by Kings Industries).

[0055] <Binder> The binder in the present invention contains fluorine atoms. When the binder for the insulating layer contains fluorine atoms, oxidation resistance against the oxidation potential of the positive electrode can be obtained when the insulating layer is formed on the positive electrode or on a separator facing the positive electrode.

[0056] The method for analyzing whether the binder in the liquid composition for forming an insulating layer contains fluorine is not particularly limited and can be appropriately selected depending on the purpose. For example, measurement can be performed using SEM-EDX (Phenom ProX tabletop SEM, manufactured by Thermo Fisher Scientific) or TOF-SIMS (TOF-SIMS.5, manufactured by ION-TOF).

[0057] The binder for the insulating layer preferably contains a fluororesin. The fluororesin is not particularly limited and can be appropriately selected depending on the purpose, but it is preferable that the fluororesin contains at least one selected from PVDF (Polyvinylidene DiFluoride), PVDF-HFP (Poly(vinylidene fluoride-hexanuopropylene), poly(vinylidene fluoride-co-hexafluoropropylene)), PTFE (Polytetrafluoroethylene), and PEVE (Perfluoroethylvinyl Ether).

[0058] There are no particular limitations on the method for confirming whether the binder in the liquid composition for forming an insulating layer contains these compounds, and the method can be appropriately selected depending on the purpose, such as Fourier transform infrared spectroscopy (FT-IR).

[0059] From the viewpoint of improving film strength, it is more preferable that the binder for the insulating layer is a combination of a fluororesin and an acrylic resin. Furthermore, from the viewpoint of improving the dispersibility of solids in the liquid composition for forming an insulating layer, it is more preferable that the acrylic resin has an interpenetrating polymer network (IPN) structure, i.e., a structure in which multiple polymers exist independently and are entangled with each other without forming a crosslinked network through chemical bonds. Furthermore, in addition to the interpenetrating polymer network structure, a crosslinked structure may also be present.

[0060] When a combination of a fluororesin and an acrylic resin is used as the binder for the insulating layer, from the viewpoint of chemical stability and improving the ejection properties of the liquid composition for forming an insulating layer, the content of the fluororesin is preferably 50 mass % or more, more preferably 65 mass % or more, and even more preferably 70 mass % or more, based on the total amount of the binder for the insulating layer. The content of the acrylic resin is preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less, based on the total amount of the binder for the insulating layer.

[0061] The binder content in the liquid composition for forming an insulating layer of the present invention is 1% by mass or more and 8% by mass or less, preferably 1.5% by mass or more and 7% by mass or less, and more preferably 2% by mass or more and 5% by mass or less, based on the total amount of the insulating inorganic particles. When the binder content in the liquid composition for forming an insulating layer is 1% by mass or more and 8% by mass or less relative to the total amount of insulating inorganic particles, the binder can be unevenly distributed on the surface of the insulating layer when the insulating layer is formed, thereby improving the abrasion resistance of the insulating layer and reducing the element resistance of the electrochemical element. Furthermore, when the content of the binder in the insulating layer-forming liquid composition is 1 mass % or more relative to the total amount of the insulating inorganic particles, the binding strength between the insulating inorganic particles improves, and the film strength of the resulting insulating layer improves. Furthermore, when the content of the binder in the liquid composition for forming an insulating layer is 8 mass % or less relative to the total amount of the insulating inorganic particles, the resulting insulating layer (electrochemical element) can eliminate problems such as a decrease in output due to an increase in battery resistance caused by the resin and a decrease in cycle characteristics.

[0062] The binder for forming the insulating layer is preferably dispersed alone in the electrolyte solvent. The fact that the binder for forming the insulating layer can be dispersed alone in the electrolyte solvent indicates that the dispersion state is stable and that the binder has high affinity for the electrolyte solvent, which results in good lithium ion conductivity of the resulting insulating layer.

[0063] There are no particular limitations on the method for determining whether the insulating layer-forming binder is dispersed in the electrolyte solvent, and the method can be appropriately selected depending on the purpose. For example, the aqueous dispersion or the dispersion in a solvent is dried once to form a solid, and then the insulating layer-forming binder is added to the electrolyte solvent (e.g., dimethyl carbonate) so that the binder is 1% relative to the electrolyte solvent, and the mixture is stirred, and it can be determined by checking whether any precipitated solid is produced.

[0064] The binder for the insulating layer may be an appropriately synthesized one or a commercially available product. Examples of commercially available insulating layer binders include Kynar Flex (registered trademark) LBG2200LX, Kynar Aquatec (registered trademark) ARC, Kynar Aquatec CRX, and Kynar Aquatec FMA-12 (all manufactured by Arkema), Lumiflon FE4300 (manufactured by AGC Inc.), and MPT-N8 (manufactured by Mitsubishi Pencil Co., Ltd.). Among these, commercially available insulating layer binders that combine fluororesin and acrylic resin with an interpenetrating polymer network structure are known as Kynar Aquatec ARC, Kynar Aquatec CRX, and Kynar Aquatec FMA-12 (all manufactured by Arkema). Among these, commercially available insulating layer binders in which the fluororesin content is 60 mass % or more relative to the total amount of the insulating layer binder are Kynar Aquatec ARC (manufactured by Arkema) and Kynar Aquatec CRX (manufactured by Arkema). Among these, commercially available insulating layer binders that disperse in an electrolyte solvent are called Kynar Flex LBG2200LX, Kynar Aquatec ARC, and Kynar Aquatec CRX.

[0065] <Solvent> The insulating layer-forming liquid composition of the present invention may contain a solvent. In this specification, the solvent in the insulating layer-forming liquid composition may be referred to as "insulating layer solvent." The solvent for the insulating layer refers to water or an aqueous solvent. Note that when the insulating layer is applied to a positive electrode, a non-aqueous solvent is preferred because deterioration of battery characteristics is expected due to a reaction between the active material and water, and the solvent may contain a small amount of water. When the insulating layer solvent contains water, it is preferable that the water content in the insulating layer-forming liquid composition is less than 10%, since this allows the water to be removed using a desiccant such as a molecular sieve before coating. When water is removed using a molecular sieve or the like, the solids concentration increases by the amount of water reduced in the insulating layer-forming liquid composition, which tends to increase the viscosity of the insulating layer-forming liquid composition. In this case, it is preferable to dilute the liquid composition with another solvent to adjust the viscosity appropriately. On the other hand, it is acceptable to leave the liquid composition containing water as long as the drying conditions in the coating process do not cause any reactions that lead to deterioration of battery characteristics.

[0066] The non-aqueous solvent is not particularly limited, and can be appropriately selected as long as it does not completely dissolve the binder for the insulating layer. Examples include methanol, ethanol, n-propanol, isopropanol (IPA), n-butanol, isobutanol, ter-butanol, n-pentanol, n-hexanol, butyl acetate, ethyl lactate, ethylene carbonate, ethylene glycol diacetate, propylene glycol, ethylene glycol, isopropyl alcohol, ethylene glycol, triethylene glycol, hexylene glycol, propylene glycol, diacetone alcohol, and cyclohexanol. These solvents may be used alone or in combination of two or more.

[0067] The content of the solvent is not particularly limited and can be appropriately selected depending on the purpose, and can be, for example, 30% by mass or more and 80% by mass or less relative to the total amount of the liquid composition.

[0068] <Other ingredients> The liquid composition for forming an insulating layer of the present invention may contain, as other components, surfactants, pH adjusters, rust inhibitors, preservatives, antifungal agents, antioxidants, antireducing agents, evaporation promoters, chelating agents, etc., for the purposes of adjusting viscosity, adjusting particle size, adjusting surface tension, controlling evaporation of non-aqueous solvents, improving the solubility of additives, improving particle dispersibility, sterilization, etc. The content of other components is not particularly limited and can be set appropriately depending on the content of various components in the liquid composition.

[0069] [viscosity] The viscosity of the insulating layer-forming liquid composition of the present invention is not particularly limited and can be appropriately selected depending on the purpose. However, from the viewpoint of improving the ejection properties by inkjet, the viscosity is preferably 5.0 mPa·s or more and 30 mPa·s or less, and more preferably 12 mPa·s or less, at 25°C and 1 atmosphere.

[0070] The method for measuring the viscosity of the liquid composition for forming an insulating layer of the present invention is not particularly limited and can be selected appropriately depending on the purpose. For example, the viscosity can be measured using a b-type viscometer (TVE-25L, manufactured by Toki Sangyo Co., Ltd.) with a standard rotor of 1°34' x R24.

[0071] [surface tension] The surface tension of the liquid composition for forming an insulating layer of the present invention is not particularly limited and can be selected appropriately depending on the purpose, but from the viewpoint of improving ejection properties by inkjet, it is preferably 25 mN / m or more and 40 mN / m or less.

[0072] <Method of manufacturing liquid composition for forming insulating layer> The method for producing the insulating layer-forming liquid composition of the present invention is not particularly limited and can be appropriately selected depending on the purpose, and can be obtained, for example, by adding solvent B, in which an insulating layer-forming binder and other components are dissolved, to a dispersion in which insulating inorganic particles and a dispersant are dispersed in solvent A, and dispersing the mixture. Solvent A and solvent B may be the same solvent or different solvents. The dispersion may be prepared by pre-stirring the solvent, insulating inorganic particles, and dispersant in a dispersing machine. The dispersing machine is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a stirrer, a ball mill, a bead mill, a ring mill, a high-pressure dispersing machine, a rotary high-speed shearing device, and an ultrasonic dispersing machine.

[0073] The insulating layer-forming liquid composition is preferably used by applying it to a medium to be coated. The medium to be coated is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a medium (porous body) capable of absorbing the insulating layer-forming liquid composition. More specifically, examples thereof include plain paper, a medium in which an ink-receiving layer is formed by coating porous particles on a base paper, a base layer used in a reflective display element, an electrode layer used in printed electronics, etc. Furthermore, when an electrode having an electrode mixture layer formed on an electrode substrate is used as the coating medium, a separator-integrated electrode or the like can be manufactured.

[0074] (electrode) The electrode of the present invention has a substrate, an electrode mixture layer provided on a portion of the substrate, and an insulating layer covering the boundary between the substrate exposed portion where the substrate is exposed and the electrode mixture layer, wherein the insulating layer contains insulating inorganic particles, a resin containing fluorine atoms, and a crosslinked resin containing at least one selected from the structural unit represented by general formula (5) and the structural unit represented by general formula (6), and may contain other members and other components as necessary. The insulating layer in the electrode of the present invention is formed from the insulating layer-forming liquid composition of the present invention, and therefore, explanations that overlap with the section (insulating layer-forming liquid composition) in this specification will be omitted.

[0075] [ka]

[0076] [ka] (In the general formulas (5) and (6), * represents a bonding site to an adjacent main chain structural unit, R represents at least one structure selected from the group consisting of polyurethane, polyester, polyethylene oxide, polypropylene oxide, poloxamer, polycarbonate, silicone, polybutadiene, and hydrogenated polybutadiene butane, and o, p, q, and r represent integers of 2 to 500.)

[0077] Here, an embodiment of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments. In each drawing, the same components are denoted by the same reference numerals, and redundant explanations may be omitted. Furthermore, the number, position, shape, etc. of the components are not limited to the present embodiment, and the number, position, shape, etc. may be any number, position, shape, etc. that is preferable for implementing the present invention.

[0078] [Figure 1, Figure 2A] Fig. 1 is a schematic diagram showing an electrode according to one embodiment of the present invention, and Fig. 2A is a schematic cross-sectional view taken along line AA' in Fig. 1. The electrode has a base 1, an electrode mixture layer 2 provided on a portion of the base 1, and an insulating layer 3. The insulating layer 3 is provided at the boundary between the electrode mixture layer 2 and a base exposed portion 11 where the base 1 is exposed. Although Figure 2A illustrates a configuration in which the electrode mixture layer 2 and the insulating layer 3 are provided on one side of the base 1, the electrode mixture layer 2 and the insulating resin layer 3 may be provided on both opposing sides of the base 1.

[0079] <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.

[0080] <Electrode composite layer> The electrode mixture layer is provided on a portion of the substrate. In other words, the electrode mixture layer is formed so as to leave an exposed portion of the substrate where no electrode mixture layer is provided, for the purpose of providing an insulating layer or welding a lead. The electrode mixture layer (sometimes referred to as "active material layer") is composed mainly of an active material (negative electrode active material or positive electrode active material). In this specification, "composed mainly of an active material" means that the content of the active material is 70 mass % or more of the entire electrode mixture layer.

[0081] The electrode mixture layer is made of an electrode mixture layer-forming liquid composition. The liquid composition for forming an electrode composite layer is not particularly limited and can be appropriately selected depending on the purpose. For example, it contains an active material (negative electrode active material or positive electrode active material), and may contain a conductive additive, a binder for the electrode composite layer, a dispersant for the electrode composite layer, a solid electrolyte, and other components as necessary.

[0082] [Figures 2B-2C] Here, Figure 2B is a schematic cross-sectional view showing an electrode according to another embodiment of the present invention, and Figure 2C is a schematic cross-sectional view showing an electrode according to another embodiment of the present invention. The electrode mixture layer may have openings 21 as shown in FIG. 2B. The number of openings 21 is preferably one or more, and more preferably two or more. The opening 21 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 21 may be hollow or may be filled with the material 22. When the opening 21 is filled with the material 22, the material 22 may be a single type or a mixture of two or more types, but in either case, the material 22 is different from the material constituting the electrode mixture layer. From the viewpoint of improving ion conductivity, the material 22 is preferably a material having a solid electrolyte. The electrode mixture layer having the openings 21 can be suitably produced by using inkjet as the electrode mixture layer forming means, since application control is easy.

[0083] As shown in FIG. 2C, the electrode mixture layer may have an adhesive layer 23 between the substrate 1 and the electrode mixture layer 2, the adhesive layer 23 containing a metal that alloys with lithium. When an adhesive layer 23 is provided between the substrate 1 and the electrode mixture layer 2, the boundary between the adhesive layer 23 and the substrate exposed portion 11 is defined as the boundary in the present invention.

[0084] <<Active material>> The active material may be a positive electrode active material or a negative electrode active material. The positive electrode active material or the negative electrode active material may be used alone or in combination of two or more.

[0085] -Cathode active material- The positive electrode active material is not particularly limited as long as it is a material that can reversibly store and release alkali metal ions, and alkali metal-containing transition metal compounds can be used. 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. Examples of lithium-containing transition metal compounds include lithium cobalt oxide, lithium nickel oxide, and lithium manganese oxide.

[0086] 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 be used. Among these, lithium-containing transition metal phosphate compounds such as lithium iron phosphate and lithium vanadium phosphate are preferred from the viewpoint of cycle characteristics, and lithium vanadium phosphate is more preferred from the viewpoint of lithium diffusion coefficient and output characteristics. When a polyanionic compound is used, it is preferable that the surface of the compound is coated with a conductive aid such as a carbon material to form a composite, in terms of electron conductivity.

[0087] The alkali metal-containing transition metal compound preferably has at least a portion of its surface coated with an ion-conductive oxide, preferably a lithium ion-conductive oxide. The lithium ion conductive oxide is not particularly limited and can be appropriately selected depending on the purpose. For example, x AO y (A is B, C, Al, Si, P, S, Ti, Zr, Nb, Mo, Ta, Sc, V, Y, Ca, Sr, Ba, Hf, Ta, Cr or W, and x and y are positive numbers). Specific examples of lithium ion conductive oxides include Li3BO3, LiBO2, Li2CO3, LiAlO2, Li4SiO4, Li2SiO3, Li3PO4, Li2SO4, Li2TiO3, and Li4Ti5O. 12 , Li2Ti2O5, Li2ZrO3, LiNbO3, LiTaO3, Li2MoO4, and Li2WO4. Among these, Li4Ti5O 12 , Li2ZrO3, or LiNbO3 are preferred. The lithium ion conductive oxide may be a composite oxide, which may be any combination of lithium ion conductive oxides, such as Li4SiO4-Li3BO3 and Li4SiO4-Li3PO4.

[0088] -Negative electrode active material- The negative electrode active material is not particularly limited as long as it is a material that can reversibly absorb and release alkali metal ions and can be appropriately selected depending on the purpose. For example, a carbon material containing graphite having a graphite-type crystal structure can be used. Examples of carbon materials include natural graphite, spherical or fibrous artificial graphite, non-graphitizable carbon (hard carbon), and easily graphitizable carbon (soft carbon). Examples of materials other than carbon materials include lithium titanate and titanium oxide. From the viewpoint of increasing the energy density of a lithium ion battery, high-capacity materials such as silicone, tin, silicone alloys, tin alloys, silicone oxide, silicone nitride, and tin oxide can also be suitably used as the negative electrode active material.

[0089] <<Conductive additives>> The conductive additive is not particularly limited and can be appropriately selected depending on the purpose. For example, carbon black produced by a furnace method, an acetylene method, a gasification method, or the like, or a carbon material such as carbon nanofiber, carbon nanotube, graphene, or graphite particles can be used. Examples of the conductive additive other than the carbon material include metal particles such as aluminum, metal fibers, etc. The conductive additive may be previously compounded with the active material.

[0090] The content of the conductive additive relative to the active material is not particularly limited and can be set appropriately depending on the purpose, but is preferably 10% by mass or less, and more preferably 8% by mass or less. If the content of the conductive auxiliary agent relative to the active material is 10% by mass or less, the stability of the electrode mixture layer-forming liquid composition is improved, which is preferable. If the content of the conductive auxiliary agent relative to the active material is 8% by mass or less, the stability of the electrode mixture layer-forming liquid composition is further improved, which is preferable.

[0091] <<Binder for electrode mixture layer>> The electrode mixture layer binder is not particularly limited and can be appropriately selected depending on the purpose, as long as it can bind negative electrode materials together, positive electrode materials together, a negative electrode material and a negative electrode substrate, or a positive electrode material and a positive electrode substrate. When the electrode mixture layer-forming liquid composition is used for inkjet ejection, it is preferable that the electrode mixture layer binder is one that does not easily increase the viscosity of the electrode mixture layer-forming liquid composition, from the viewpoint of suppressing nozzle clogging of the liquid ejection head. In this specification, a distinction is made between the "binder" or "insulating layer binder" in the insulating layer-forming liquid composition and the "electrode mixture layer binder" in the electrode mixture layer-forming liquid composition.

[0092] As the binder for the electrode mixture layer, a polymer compound can be used. Examples of polymer compounds include thermoplastic resins such as polyvinylidene fluoride (PVDF), acrylic resin, polyethylene, polypropylene, polyurethane, nylon, polytetrafluoroethylene, polyphenylene sulfide, polyethylene terephthalate, and polybutylene terephthalate, polyamide compounds, polyimide compounds, polyamideimide, ethylene-propylene-butadiene rubber (EPBR), styrene-butadiene rubber (SBR), nitrile butadiene rubber (NBR), isoprene rubber, polyisobutene, polyethylene glycol (PEO), polymethylmethacrylate (PMMA), and polyethylene vinyl acetate (PEVA).

[0093] The content of the binder for the electrode mixture layer relative to the active material is not particularly limited and can be set appropriately depending on the purpose, but is preferably 1% by mass or more and 15% by mass or less, and more preferably 3% by mass or more and 10% by mass or less. If the content of the binder for the electrode mixture layer relative to the active material is 1% by mass or more, the active material can be firmly bound to the base, which is preferable.

[0094] <<Dispersant for electrode mixture layer>> The dispersant for the electrode mixture layer is not particularly limited as long as it is capable of improving the dispersibility of the active material in the liquid composition for forming the electrode mixture layer. Examples include polymer dispersants such as polyethylene oxides, polypropylene oxides, polycarboxylic acids, naphthalenesulfonic acid formalin condensation, 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. In this specification, a distinction is made between a "dispersant" or a "dispersant for insulating layer" in the liquid composition for forming an insulating layer and a "dispersant for electrode mixture layer" in the liquid composition for forming an electrode mixture layer.

[0095] <<Solid electrolyte>> The solid electrolyte is not particularly limited as long as it is a solid substance that has electronic insulation properties and exhibits ionic conductivity, but sulfide solid electrolytes and oxide solid electrolytes are preferred from the viewpoint of high ionic conductivity.

[0096] Examples of sulfide solid electrolytes include Li 10 GeP2S 12 and Li6PS5X (X=F, Cl, Br, I) which has an argyrodite-type crystal structure. As an oxide-based solid electrolyte, for example, LLZ (Li7La3Zr2O 12 ), LATP (Li1+xAlxTi) with NASICON-type crystal structure 20 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.

[0097] When the electrode mixture layer is a positive electrode mixture layer, the average thickness of the positive electrode mixture layer is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 10 μm or more and 300 μm or less, and more preferably 40 μm or more and 150 μm or less. When the average thickness of the positive electrode mixture layer is 10 μm or more, the energy density of the electrochemical device is improved. When the average thickness of the negative electrode mixture layer is 300 μm or less, the load characteristics of the electrochemical device are improved.

[0098] When the electrode mixture layer is a negative electrode mixture layer, the average thickness of the negative electrode mixture layer is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 10 μm or more and 450 μm or less, and more preferably 20 μm or more and 100 μm or less. When the average thickness of the negative electrode mixture layer is 10 μm or more, the energy density of the electrochemical device is improved. When the average thickness of the negative electrode mixture layer is 450 μm or less, the cycle characteristics of the electrochemical device are improved.

[0099] The electrode mixture layer may be formed on both sides of the substrate (positive electrode substrate and / or negative electrode substrate). The electrodes may be stacked in multiple layers to increase the charge / discharge capacity of the electrodes. The number of stacked positive and negative electrodes is not particularly limited, and can be increased as needed.

[0100] <Insulating layer> The insulating layer in the electrode of the present invention is provided so as to cover the boundary between the exposed portion of the substrate where the substrate is exposed and the electrode mixture layer. The insulating layer contains insulating inorganic particles, a resin containing fluorine atoms, and a crosslinked resin containing at least one selected from the structural unit represented by general formula (5) and the structural unit represented by general formula (6), and may contain other components as necessary.

[0101] [ka]

[0102] [ka] (In the general formulas (5) and (6), * represents a bonding site to an adjacent main chain structural unit, R represents at least one structure selected from the group consisting of polyurethane, polyester, polyethylene oxide, polypropylene oxide, poloxamer, polycarbonate, silicone, polybutadiene, and hydrogenated polybutadiene butane, and o, p, q, and r represent integers of 2 to 500.)

[0103] The dispersant and crosslinker in the insulating layer-forming liquid composition react during the secondary drying step of the insulating layer-forming liquid composition to form a crosslinked resin containing a structural unit represented by general formula (5) or a structural unit represented by general formula (6). The crosslinked resin is a resin in which the main chains of polymer molecules are linked by chemical bonds, resulting in a three-dimensional structure. The crosslinked resin containing the structural unit represented by general formula (5) or the structural unit represented by general formula (6) is insoluble in nonaqueous electrolyte solvents, thereby preventing an increase in the electrolyte resistance of electrochemical elements. The crosslinked resin improves the film strength of the insulating layer obtained by secondary drying the insulating layer-forming liquid composition.

[0104] There are no particular restrictions on o in general formula (5) and it can be appropriately selected depending on the purpose, but it is preferably an integer of 10 to 100. There are no particular restrictions on p in the general formula (5) and it can be appropriately selected depending on the purpose, but it is preferably an integer of 10 to 100. There are no particular restrictions on q in general formula (6) and it can be appropriately selected depending on the purpose, but it is preferably an integer of 10 to 100. There are no particular restrictions on r in general formula (6) and it can be appropriately selected depending on the purpose, but it is preferably an integer of 10 to 100.

[0105] The method for determining whether the crosslinked resin in the insulating layer contains the structural units represented by the general formulas (5) to (6) is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include infrared spectroscopy (IR). More specifically, the crosslinked resin having the structural unit represented by the general formula (5) may contain the structural unit represented by the general formula (1) at 1782 cm. -1 and 1858 cm -1 It is confirmed that the peak at 1734 cm , which is presumed to be due to the C═O stretching vibration of -COOR, -COOH, etc., decreases compared to before the secondary drying process of the liquid composition for forming an insulating layer. -1 Check for an increase in the peak. The peak presumably derived from the bond of the crosslinked resin having the repeating structural units represented by the general formulas (2) and (3) is at 1734 cm -1 Therefore, the presence or absence of a reaction cannot be confirmed by IR analysis, but it can be determined by the presence or absence of solubility in the non-aqueous electrolyte.

[0106] The content of the crosslinked resin is not particularly limited and can be selected appropriately depending on the content of the dispersant and crosslinking agent in the liquid composition for forming an insulating layer, but is preferably 1.5% by mass or more and 10% by mass or less, more preferably 2% by mass or more and 8% by mass or less, and even more preferably 2.5% by mass or more and 6% by mass or less, based on the total amount of the insulating inorganic particles.

[0107] The weight of the insulating layer relative to the electrode mixture layer is not particularly limited and can be appropriately selected depending on the purpose. 2 More than 1.5mg / cm 2 Less than 0.4 mg / cm is preferred 2 More than 1.5mg / cm 2 Less than 0.5 mg / cm is more preferable. 2 More than 1.5mg / cm 2 The following is even more preferred:

[0108] [Figures 3A-3B] Here, Figure 3A is a schematic cross-sectional view showing an electrode according to another embodiment of the present invention, and Figure 3B is a schematic cross-sectional view showing an electrode according to another embodiment of the present invention. 3A, the insulating layer 3 may be provided at the boundary portion and on the edge portion of the electrode mixture layer 2. As shown in FIG. 3B, the insulating layer 3 may be provided at the boundary portion and on the upper surface of the electrode mixture layer 2. When the insulating layer 3 is provided on the upper surface of the electrode mixture layer 2, the coverage of the upper surface of the electrode mixture layer 2 by the insulating layer 3 is preferably 70% or more, more preferably 80% or more, and even more preferably 90% or more. In other words, when the insulating layer 3 is provided on the upper surface of the electrode mixture layer 2, an exposed region that is not covered by the insulating layer 3 may exist on the upper surface of the electrode mixture layer 2. By providing the insulating layer 3 on the electrode mixture layer 2, when coating by inkjet, it is possible to form an insulating layer with a small thickness and uniformity, and the stability of the battery is improved.

[0109] When an insulating layer is provided on the end of the electrode mixture layer, the average thickness of the insulating layer is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 1 μm or more and 20 μm or less, and more preferably 3 μm or more and 10 μm or less. If the average thickness of the insulating layer is 1 μm or more, sufficient insulating properties are obtained, which is preferable. When the average thickness of the insulating layer is 20 μm or less, problems such as the electrode mixture layer being damaged by the weight of the liquid composition itself when applying the liquid composition, or the liquid composition flowing and causing unevenness can be eliminated. When an insulating layer is provided on the upper surface of the electrode mixture layer, the average thickness of the insulating layer is not particularly limited and can be selected appropriately depending on the purpose, but from the viewpoint of improving the safety of the battery, it is preferably 0.5 μm or more and 24 μm or less.

[0110] The method for measuring the average thickness of the insulating layer is not particularly limited and can be appropriately selected depending on the purpose. For example, the average thickness can be measured using a Digimatic Micrometer (manufactured by Mitutoyo Corporation).

[0111] The width of the insulating layer in FIG. 3A is not particularly limited and can be appropriately selected depending on the battery configuration, but is preferably 2 mm or more and 30 mm or less. The "width" of the insulating layer refers to the distance (in the longitudinal direction of the electrode) from one end to the other end of the upper surface of the insulating layer facing the substrate surface in contact with the electrode composite layer in a cross-sectional view when the electrode is cut in the thickness direction of the electrode and in a direction parallel to the longitudinal direction of the electrode. If the width of the insulating layer is 2 mm or more, it is difficult for the insulating layer to follow the meandering of the electrode mixture layer, and the problem of the exposed portion of the substrate not being covered by the insulating layer can be resolved. If the width of the insulating layer is 30 mm or less, problems such as impediments to lead welding and battery size being too large for the battery capacity can be resolved. In addition, the width of the insulating layer that protrudes onto the base in FIG. 3B can be set appropriately within a range that does not interfere with the welding of the leads.

[0112] The width of the insulating layer covering the electrode mixture layer in FIG. 3A is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.1 mm or more and 5 mm or less. In this specification, the term "cover width" refers to the distance (in the longitudinal direction of the electrode) from one end to the other end of the surface where the electrode mixture layer and the insulating layer contact, facing the substrate surface in contact with the electrode mixture layer, in a cross-sectional view when the electrode is cut in the thickness direction of the electrode and in a direction parallel to the longitudinal direction of the electrode. If the covering width is 0.1 mm or more, it is difficult to follow the meandering of the electrode mixture layer, and the problem of the exposed portion of the substrate not being covered with the insulating layer can be resolved. If the covering width is 5 mm or less, it is possible to prevent the insulating layer from adversely affecting the battery capacity.

[0113] [Figures 4 and 5] Here, Fig. 4 is a schematic diagram showing an insulating layer on an electrode according to one embodiment of the present invention, and Fig. 5 is a schematic diagram showing an insulating layer on an electrode according to another embodiment of the present invention. The shape of the insulating layer 3 provided on the substrate and the electrode mixture layer is not particularly limited and can be appropriately selected depending on the purpose. For example, it may be a solid film, a line pattern as shown in FIG. 4, or a grid pattern as shown in FIG. 5. The shape of the insulating layer 3 provided on the substrate and the electrode mixture layer can be drawn based on, for example, bitmap information. Bitmap information is digital image information used in ordinary digital printing.

[0114] The shape of the electrode is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a flat plate shape. The size of the electrodes is not particularly limited and can be appropriately selected depending on the purpose, and the positive electrode and the negative electrode may have different sizes.

[0115] (Electrode manufacturing method and electrode manufacturing device) The electrode manufacturing method of the present invention is an electrode manufacturing method including an insulating layer forming step, and the insulating layer forming step includes an insulating layer forming liquid composition applying step, and may optionally include an electrode mixture layer forming step, an insulating layer forming liquid composition drying step, and other steps. The electrode manufacturing apparatus according to the present invention is an electrode manufacturing apparatus including an insulating layer forming means, and the insulating layer forming means includes an insulating layer forming liquid composition applying means, and may also have an electrode mixture layer forming means, an insulating layer forming liquid composition drying means, and other means, as necessary.

[0116] <Electrode mixture layer forming step and electrode mixture layer forming means> The electrode mixture layer forming step is a step of forming an electrode mixture layer on a part of a substrate, and preferably includes an electrode mixture layer forming liquid composition applying step and an electrode mixture layer forming liquid composition drying step. The electrode mixture layer forming means is means for forming an electrode mixture layer on a part of the substrate, and preferably includes an electrode mixture layer forming liquid composition applying means and an electrode mixture layer forming liquid composition drying means. The electrode mixture layer forming step can be suitably carried out by an electrode mixture layer forming means.

[0117] <<Electrode mixture layer forming liquid composition applying step and electrode mixture layer forming liquid composition applying means>> The electrode mixture layer forming liquid composition applying step is a step of applying the electrode mixture layer forming liquid composition to a part of the substrate. The electrode mixture layer forming liquid composition applying means is a means for applying the electrode mixture layer forming liquid composition to a part of the substrate. The electrode mixture layer forming liquid composition applying step can be suitably carried out by an electrode mixture layer forming liquid composition applying means.

[0118] When producing a positive electrode, a liquid composition for forming an electrode mixture layer (liquid composition for forming a positive electrode mixture layer) is applied onto a positive electrode substrate to form a positive electrode mixture layer. When producing a negative electrode, an electrode mixture layer-forming liquid composition (negative electrode mixture layer-forming liquid composition) is applied onto a negative electrode substrate to form a negative electrode mixture layer.

[0119] The means for applying the electrode mixture layer-forming liquid composition is not particularly limited and can be appropriately selected depending on the purpose, and examples include dip coating, spray coating, spin coating, bar coating, slot die coating, doctor blade coating, offset printing, gravure printing, flexographic printing, letterpress printing, screen printing, liquid ejection, electrophotographic printing using a liquid development system, etc. Among these, the liquid ejection method is preferred because it allows precise control of the ejection position and ejection amount of droplets.

[0120] When a liquid ejection method is used, the electrode mixture layer forming liquid composition is ejected onto the substrate from a liquid ejection head. Examples of methods for ejecting the electrode mixture layer-forming liquid composition include a method of applying mechanical energy to the electrode mixture layer-forming liquid composition, a method of applying thermal energy to the electrode mixture layer-forming liquid composition, etc. Among these, when a non-aqueous solvent is used, the method of applying mechanical energy to the electrode mixture layer-forming liquid composition is preferred, and the inkjet method is more preferred. When a liquid ejection method is used, a known liquid ejection device can be used.

[0121] <<Electrode mixture layer forming liquid composition drying step and electrode mixture layer forming liquid composition drying means>> The electrode mixture layer forming liquid composition drying step is a step of drying the electrode mixture layer forming liquid composition applied onto the substrate. The electrode mixture layer forming liquid composition drying means is a means for drying the electrode mixture layer forming liquid composition applied onto the substrate. The electrode mixture layer forming liquid composition drying step can be suitably carried out by an electrode mixture layer forming liquid composition drying means.

[0122] The means (step) for drying the liquid composition for forming an electrode composite layer is not particularly limited and can be selected appropriately depending on the purpose. Examples include a method of heating the coated surface with a resistance heater, an infrared heater, a fan heater, etc., and a method of drying from the back side of the coated surface with a hot plate, a drum heater, etc. Among these, from the viewpoint of uniformly heating and drying the coated surface, a resistance heater, an infrared heater, and a fan heater, which are capable of drying the coated surface without contact, are preferred. These heating mechanisms may be used alone or in combination of two or more.

[0123] The heating temperature in the drying step of the liquid composition for forming an electrode mixture layer is not particularly limited and can be selected appropriately depending on the purpose, but from the viewpoint of protecting the substrate and the active material of the electrode mixture layer, it is preferably 70°C or higher and 150°C or lower.

[0124] <Insulating layer forming step and insulating layer forming means> The insulating layer forming step is a step of forming an insulating layer so as to cover the boundary between the exposed portion of the substrate where the substrate is exposed and the electrode mixture layer. The insulating layer forming step preferably includes an insulating layer forming liquid composition applying step and an insulating layer forming liquid composition drying step. The insulating layer forming means is a means for forming an insulating layer so as to cover the boundary between the exposed portion of the substrate where the substrate is exposed and the electrode mixture layer, and preferably includes an insulating layer forming liquid composition applying means and an insulating layer forming liquid composition drying means. The insulating layer forming step can be suitably carried out by an insulating layer forming means.

[0125] <<Insulating layer forming liquid composition applying step and insulating layer forming liquid composition applying means>> The insulating layer forming liquid composition applying step is a step of applying the insulating layer forming liquid composition to the boundary between the exposed portion of the substrate where the substrate is exposed and the electrode mixture layer. The insulating layer forming liquid composition applying means is a means for applying the insulating layer forming liquid composition to the boundary between the exposed portion of the substrate where the substrate is exposed and the electrode mixture layer. The step of applying the insulating layer-forming liquid composition can be suitably carried out by an insulating layer-forming liquid composition applying means.

[0126] As the means for applying the insulating layer-forming liquid composition, the same means as those described in the section <<Step of applying the electrode mixture layer-forming liquid composition, and means for applying the electrode mixture layer-forming liquid composition>> can be used.

[0127] <<Insulating layer forming liquid composition drying step and insulating layer forming liquid composition drying means>> The insulating layer forming liquid composition drying step is a step of drying the applied insulating layer forming liquid composition. The insulating layer forming liquid composition drying means is a means for drying the applied insulating layer forming liquid composition. The step of drying the insulating layer-forming liquid composition can be suitably carried out by means of drying the insulating layer-forming liquid composition.

[0128] [Figure 6] FIG. 6 is a schematic cross-sectional view showing an example of an electrode obtained by the step of drying the insulating layer-forming liquid composition of the present invention. By the insulating layer forming liquid composition drying process, the insulating layer binder 302 can be concentrated on the surface of the insulating layer 3 based on the difference in specific gravity between the insulating layer binder 302 contained in the insulating layer forming liquid composition and the insulating inorganic particles 301 (see Figure 6). In this specification, the "surface of the insulating layer" refers to the region (surface-side region) on the opposite side of the imaginary line from the base 2 (thickness direction of the insulating layer) when an imaginary line is drawn at half the average thickness of the insulating layer, with the surface of the insulating layer facing the base as the reference in the cross section of the electrode. Also, the region on the base 2 side of the imaginary line is referred to as the base-side region.

[0129] The uneven distribution rate of the binder for the insulating layer is not particularly limited and can be selected appropriately depending on the purpose, but the amount of binder in the base side region relative to the amount of binder in the surface side region is preferably 30% or less, and more preferably 10% or less.

[0130] There are no particular limitations on the method for checking whether the insulating layer binder is unevenly distributed on the surface of the insulating layer, and it can be selected appropriately depending on the purpose, for example, by measuring the abrasion strength and 90-degree peel strength. More specifically, it can be checked by measuring whether particles do not adhere when the insulating layer is rubbed with a rubber glove and whether the peel strength is 30 N / m or more and less than 250 N / m.

[0131] When the medium to which the insulating layer-forming liquid composition is applied is a porous body such as an electrode mixture layer, during the process from application of the liquid composition to drying, the dispersant and cross-linking agent 303 are unevenly distributed at the interface between the lower part of the insulating layer and the upper part of the electrode mixture layer when the solvent contained in the liquid composition penetrates into the electrode mixture layer, thereby improving the bonding function of the insulating layer at the electrode mixture layer interface after cross-linked resin formation.

[0132] When the substrate in the step of applying the liquid composition for forming an insulating layer is a porous body, the time from the step of applying the liquid composition for forming an insulating layer to the step of drying the liquid composition for forming an insulating layer is preferably 2 minutes or less, and more preferably 2 seconds or more but 1 minute or less, from the viewpoint of preventing deterioration of the porous body due to excessive penetration of the liquid components containing the resin dissolved in the solvent in the applied liquid composition for forming an insulating layer from the surface of the porous body due to capillary action, and when the substrate in the step of applying the liquid composition for forming an insulating layer is a metal foil, from the viewpoint of preventing unevenness in the applied liquid composition for forming an insulating layer due to aggregation, etc.

[0133] The means (step) for drying the insulating layer-forming liquid composition is not particularly limited and can be appropriately selected depending on the purpose, and examples include a method of heating the coated surface with a resistance heater, infrared heater, fan heater, etc., and a method of drying from the backside of the coated surface with a hot plate, drum heater, etc. From the viewpoint of uniformly heating and drying the coated surface, a resistance heater, infrared heater, or fan heater that can dry the coated surface without contact is preferred. These heating mechanisms may be used alone or in combination of two or more.

[0134] The insulating layer-forming liquid composition drying step preferably includes a primary insulating layer-forming liquid composition drying step, a primary dried product processing step for the insulating layer-forming liquid composition, and a secondary insulating layer-forming liquid composition drying step.

[0135] - Primary drying process of liquid composition for forming insulating layer - The primary drying step of the insulating layer-forming liquid composition is a step of drying the insulating layer-forming liquid composition after the insulating layer-forming liquid composition application step. When the primary drying process of the liquid composition for forming an insulating layer is carried out by heating, the heating temperature is not particularly limited and can be selected appropriately depending on the purpose, but from the viewpoint of protecting the active material of the substrate and the electrode mixture layer, it is preferable that the heating temperature be 70°C or higher and 150°C or lower. It is preferable that the heating temperature in the primary drying step of the insulating layer-forming liquid composition is 70° C. or higher, since this improves the strength of the insulating layer. It is preferable that the heating temperature in the primary drying step of the insulating layer-forming liquid composition is 150° C. or less, since this can prevent bubbles resulting from bumping on the insulating layer surface.

[0136] -Insulating layer forming liquid composition primary dried product treatment process- The insulating layer-forming liquid composition primary drying treatment step is a step carried out after the insulating layer-forming liquid composition primary drying step, and examples thereof include a winding step.

[0137] -Secondary drying process of liquid composition for forming insulating layer- The insulating layer-forming liquid composition secondary drying step is a step of drying the insulating layer-forming liquid composition again after the insulating layer-forming liquid composition primary drying treatment step. When the secondary drying process of the liquid composition for forming an insulating layer is carried out by heating, the heating temperature is not particularly limited and can be selected appropriately depending on the purpose. From the viewpoint of improving the film strength, however, for a positive electrode, 100°C or higher is preferable, and 120°C or higher is more preferable, and for a separator, 60°C or higher is preferable. In the secondary drying step of the insulating layer-forming liquid composition, the higher the drying temperature, the better, from the viewpoint of shortening the time required for the crosslinked resin production reaction, and it is preferable that the drying be carried out in a vacuum environment.

[0138] <Other steps and other means> The other steps are not particularly limited and can be appropriately selected depending on the purpose. For example, there may be mentioned a cutting step in which the electrode is cut to a desired size by punching or the like. The other means are not particularly limited and can be appropriately selected depending on the purpose. For example, cutting means for cutting the electrode to a desired size by punching or the like can be used. Other steps may be suitably carried out by other means.

[0139] Here, an embodiment of an electrode manufacturing apparatus according to the present invention will be described with reference to the drawings, although the present invention is not limited to these embodiments. In each drawing, the same components are denoted by the same reference numerals, and redundant explanations may be omitted. Furthermore, the number, position, shape, etc. of the components are not limited to the present embodiment, and the number, position, shape, etc. may be any number, position, shape, etc. that is preferable for implementing the present invention.

[0140] [Figure 7] Here, FIG. 7 is a schematic diagram showing an electrode manufacturing apparatus according to one embodiment of the present invention. The electrode manufacturing apparatus 10 includes a printing unit 20, a heating unit 30, and a conveying unit 40. The printing unit 20 is an example of an electrode mixture layer forming liquid composition applying means and / or an insulating layer forming liquid composition applying means that constitute the electrode manufacturing apparatus of the embodiment, and the heating unit 30 is an example of an electrode mixture layer forming liquid composition drying means and / or an insulating layer forming liquid composition drying means that constitute the electrode manufacturing apparatus of the embodiment.

[0141] The printing unit 20 forms an electrode mixture layer and / or an insulating layer by applying the electrode mixture layer-forming liquid composition and / or the insulating layer-forming liquid composition P onto the application target medium 50. The printing unit 20 includes a storage container 20A that stores the electrode mixture layer-forming liquid composition and / or the insulating layer-forming liquid composition P, a printing device 20B that applies the electrode mixture layer-forming liquid composition and / or the insulating layer-forming liquid composition P onto the application target medium 50, and a supply tube 20C that supplies the electrode mixture layer-forming liquid composition and / or the insulating layer-forming liquid composition P stored in the storage container 20A to the printing device 20B.

[0142] During printing, printing unit 20 supplies electrode mixture layer-forming liquid composition and / or insulating layer-forming liquid composition P stored in storage container 20A to printing device 20B, and ejects electrode mixture layer-forming liquid composition and / or insulating layer-forming liquid composition P from printing device 20B onto application medium 50. As a result, electrode mixture layer-forming liquid composition and / or insulating layer-forming liquid composition P is applied onto application medium 50, and a thin film of electrode mixture layer and / or insulating layer is formed.

[0143] The storage container 20A can be selected arbitrarily as long as it can stably store the electrode mixture layer forming liquid composition and / or the insulating layer forming liquid composition P. The storage container 20A may be configured to be integrated with the electrode manufacturing apparatus 10, or may be configured to be detachable from the electrode manufacturing apparatus 10. The storage container 20A may be a container used for adding to a storage container integrated with the electrode manufacturing apparatus 10, or may be a container used for adding to a storage container detachable from the electrode manufacturing apparatus 10.

[0144] The printing device 20B is not particularly limited as long as it can apply the electrode mixture layer-forming liquid composition and / or the insulating layer-forming liquid composition P, and any printing device suitable for various printing methods such as spin coating, casting, microgravure coating, gravure coating, bar coating, roll coating, wire bar coating, dip coating, slit coating, capillary coating, spray coating, nozzle coating, gravure printing, screen printing, flexographic printing, offset printing, reverse printing, and inkjet printing can be used. Among these, it is preferable to use a printing device suitable for inkjet printing, as it can form or print a thin film on the thin-layer application medium 50 in a non-contact manner, and it reduces material costs and waste materials.

[0145] The supply tube 20C can be arbitrarily selected as long as it can stably supply the electrode mixture layer forming liquid composition and / or the insulating layer forming liquid composition P.

[0146] The heating section 30 obtains an electrode mixture layer and / or an insulating layer by heating the electrode mixture layer forming liquid composition and / or the insulating layer forming liquid composition P. The heating section 30 has a heating device 30A.

[0147] The heating device 30A heats and dries the electrode mixture layer-forming liquid composition and / or insulating layer-forming liquid composition P, thereby removing the solvent remaining in the electrode mixture layer-forming liquid composition and / or insulating layer-forming liquid composition P. As a result, the electrode mixture layer-forming liquid composition and / or insulating layer-forming liquid composition P on the application target medium 50 becomes an electrode mixture layer and / or an insulating layer. The heating temperature and heating time can be appropriately selected depending on the boiling point of the solvent contained in the electrode mixture layer forming liquid composition and / or the insulating layer forming liquid composition P, the thickness of the formed film, and the like.

[0148] The conveying unit 40 conveys the medium to be coated 50 at a preset speed in the order of the printing unit 20 and the heating unit 30. The conveying unit 40 may be any unit that can convey the medium to be coated 50, and may be, for example, a conveying belt.

[0149] Any material, whether transparent or opaque, can be used for the medium to be coated 50. That is, for the medium to be coated 50, transparent substrates include glass substrates, resin film substrates such as various plastic films, and composite substrates thereof. Opaque substrates include various substrates such as silicon substrates, metal substrates such as stainless steel, and laminates of these.

[0150] The coating medium 50 may be a recording medium such as plain paper, glossy paper, special paper, or cloth. The recording medium may also be a low-permeability substrate (low-absorbency substrate). A low-permeability substrate refers to a substrate with a surface that is low in water permeability, absorbency, or adsorption, and includes materials that have many internal cavities but are not open to the outside. Examples of low-permeability substrates include coated paper used in commercial printing and recording media such as paperboard coated with recycled paper pulp in the middle and back layers.

[0151] The application medium 50 may be a porous resin sheet used as an insulating layer for an electricity storage element or a power generation element.

[0152] The shape of the medium 50 to be coated may be curved or uneven, and any substrate that can be applied to the printing unit 20 can be used.

[0153] (electrochemical element) The electrochemical device of the present invention has electrodes. As the electrodes, the same ones as those in the (electrodes) section of this specification can be used, and therefore a duplicated description will be omitted.

[0154] Here, an embodiment of the electrochemical device of the present invention will be described with reference to the drawings, although the present invention is not limited to these embodiments. In each drawing, the same components are denoted by the same reference numerals, and redundant explanations may be omitted. Furthermore, the number, position, shape, etc. of the components are not limited to the present embodiment, and the number, position, shape, etc. may be any number, position, shape, etc. that is preferable for implementing the present invention.

[0155] [Figure 8] FIG. 8 is a schematic diagram showing an electrochemical device according to one embodiment of the present invention. The electrochemical element 500 has an electrolyte layer 501 made of a non-aqueous electrolyte formed on a laminated electrode 400, and is sealed with an exterior casing 502. In the electrochemical element 500, the lead wires 401 and 402 are drawn out to the outside of the exterior casing 502. The laminated electrode 400 is formed by laminating a negative electrode 205 and a positive electrode 105 with a separator 300 interposed therebetween. The negative electrode 205 is laminated on both sides of the positive electrode 105. A lead wire 402 is connected to the negative electrode substrate 201, and a lead wire 401 is connected to the positive electrode substrate 101. Positive electrode 105 has positive electrode substrate 101, positive electrode composite layer 102 and insulating layer 103 formed in this order on both sides of substrate 101. Negative electrode 205 has negative electrode composite layer 202 formed on both sides of negative electrode substrate 201 . The number of negative electrodes 205 and the number of positive electrodes 105 in the laminated electrode 400 may be the same or different.

[0156] The shape of the electrochemical element using the electrodes is not particularly limited, and examples thereof include a laminate type in which flat electrodes are stacked, 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. The electrochemical device 500 may include other components as necessary.

[0157] <<Non-aqueous electrolyte>> As the non-aqueous electrolyte, a non-aqueous electrolytic solution or a solid electrolyte can be used.

[0158] --Nonaqueous electrolyte-- The non-aqueous electrolyte is an electrolyte in which an electrolyte salt is dissolved in a non-aqueous solvent. The non-aqueous solvent is not particularly limited and can be appropriately selected depending on the purpose. For example, it is preferable to use an aprotic organic solvent. As the aprotic organic solvent, carbonate-based organic solvents such as chain carbonates and cyclic carbonates can be used. Among these, chain carbonates are preferred because of their high dissolving power for electrolyte salts. In addition, it is preferable that the aprotic organic solvent has low viscosity.

[0159] Examples of the chain carbonate include dimethyl carbonate (DMC), diethyl carbonate (DEC), and methyl ethyl carbonate (EMC).

[0160] 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, the content of the cyclic substance is reduced even when a cyclic substance (e.g., a cyclic carbonate or a cyclic ester) having a high dielectric constant in a non-aqueous solvent other than the chain carbonate is used. Therefore, even when a non-aqueous electrolyte solution with a high concentration of 2M or more is prepared, the viscosity of the non-aqueous electrolyte solution is reduced, resulting in good penetration of the non-aqueous electrolyte solution into the electrodes and good ion diffusion.

[0161] Examples of cyclic carbonates include propylene carbonate (PC), ethylene carbonate (EC), butylene carbonate (BC), and vinylene carbonate (VC).

[0162] Examples of non-aqueous solvents that can be used other than carbonate-based organic solvents include ester-based organic solvents such as cyclic esters and chain esters; and ether-based organic solvents such as cyclic ethers and chain ethers.

[0163] Examples of cyclic esters include γ-butyrolactone (γBL), 2-methyl-γ-butyrolactone, acetyl-γ-butyrolactone, and γ-valerolactone.

[0164] 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).

[0165] Examples of cyclic ethers include tetrahydrofuran, alkyltetrahydrofuran, alkoxytetrahydrofuran, dialkoxytetrahydrofuran, 1,3-dioxolane, alkyl-1,3-dioxolane, and 1,4-dioxolane.

[0166] Examples of the chain ether include 1,2-dimethoxyethane (DME), diethyl ether, ethylene glycol dialkyl ether, diethylene glycol dialkyl ether, triethylene glycol dialkyl ether, and tetraethylene glycol dialkyl ether.

[0167] The electrolyte salt in the non-aqueous electrolyte solution is not particularly limited as long as it has high ionic conductivity and can be dissolved in the non-aqueous solvent. The electrolyte salt in the non-aqueous electrolyte preferably contains a halogen atom. Examples of cations constituting the electrolyte salt include lithium ions. Examples of anions that constitute the electrolyte salt include BF4 - , PF6 - , AsF6 - , CF3SO3 - , (CF3SO2)2N - , (C2F5SO2)2N - Examples include: 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(CSO)), lithium bis(pentafluoroethylsulfonyl)imide (LiN(CSO)), etc. Among these, LiPF is preferred from the viewpoint of ionic conductivity, and LiBF is preferred from the viewpoint of stability. The electrolyte salt in the non-aqueous electrolyte solution may be used alone or in combination of two or more kinds.

[0168] The concentration of the electrolyte salt in the non-aqueous electrolytic solution is not particularly limited and can be appropriately selected depending on the purpose. However, when the non-aqueous electrochemical device is of a swing type, the concentration is preferably 1 mol / L to 2 mol / L, and when the non-aqueous electrochemical device is of a reserve type, the concentration is preferably 2 mol / L to 4 mol / L.

[0169] <Separator> A separator is provided between the negative electrode and the positive electrode as needed to prevent short-circuiting between the negative electrode and the positive electrode. The separator is a porous film having communicating pores that insulates and separates a positive electrode and a negative electrode used in an electrochemical element such as a secondary battery. Examples of separators include paper such as kraft paper, vinylon-mixed paper, and synthetic pulp-mixed paper; polyolefin nonwoven fabrics such as cellophane, polyethylene graft membranes, and polypropylene melt-blown nonwoven fabrics; polyamide nonwoven fabrics, glass fiber nonwoven fabrics, and micropore membranes. The size of the separator is not particularly limited as long as it can be used in an electrochemical element. The separator may have a single layer structure or a laminated structure. When an aqueous electrolyte solution or a non-aqueous electrolyte solution is used as the electrolyte, a separator is necessary, but when a solid electrolyte or a gel electrolyte is used, a separator is not necessary.

[0170] <Exterior> The exterior packaging is not particularly limited as long as it can seal the electrodes, the electrolyte, and the separator or solid electrolyte, and any known exterior packaging can be appropriately selected depending on the purpose.

[0171] [Uses of electrochemical elements] The electrochemical device can be suitably used as a secondary battery. The uses of electrochemical elements are not particularly limited, and examples thereof include notebook computers, pen-input computers, mobile computers, electronic book players, mobile phones, mobile fax machines, mobile copiers, mobile printers, headphone stereos, video movie machines, liquid crystal 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 vehicles.

[0172] (Secondary battery) The secondary battery according to the present invention has an electrochemical element. The electrochemical element may be the same as that described in the (Electrochemical element) section of this specification, and therefore a duplicated description will be omitted.

[0173] (separator) The separator of the present invention has a separator and an insulating layer provided on the separator, and the insulating layer contains insulating inorganic particles, a resin containing fluorine atoms, and a crosslinked resin containing at least one selected from the structural unit represented by general formula (5) and the structural unit represented by general formula (6), and may contain other components and other members as necessary. The separator of the present invention is similar to the item (electrode) in this specification except that a separator is used as the substrate, so a duplicated description will be omitted.

[0174] [ka]

[0175] [ka] (In the general formulas (5) and (6), * represents a bonding site to an adjacent main chain structural unit, R represents at least one structure selected from the group consisting of polyurethane, polyester, polyethylene oxide, polypropylene oxide, poloxamer, polycarbonate, silicone, polybutadiene, and hydrogenated polybutadiene butane, and o, p, q, and r represent integers of 2 to 500.)

[0176] (Separator manufacturing method) The method for producing a separator of the present invention is a method for producing a separator that includes an insulating layer forming step, and the insulating layer forming step includes an insulating layer forming liquid composition applying step of applying an insulating layer forming liquid composition onto the separator, and may include other steps as necessary. The method for producing a separator of the present invention is the same as the item (Method for producing an electrode) in this specification except that a separator is used as the substrate, so a duplicated explanation will be omitted. [Example]

[0177] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples. In the following examples and comparative examples, unless otherwise specified, "parts" means "parts by mass" and "%" means "% by mass".

[0178] Example 1 <Preparation of Liquid Composition for Forming Insulating Layer> A pre-dispersion mixture of 30.0 parts of α-alumina (CT3000LSSG, manufactured by Almatis) as insulating inorganic particles, 0.9 parts of SC-0505K (manufactured by NOF Corporation) as a dispersant, 0.3 parts of DBE-C25 (manufactured by Gelest) as a crosslinker, 3.5 parts of Kynar Aquatec ARC (manufactured by Arkema) as a binder, and 65.3 parts of ethyl lactate as a solvent was placed in a glass ball mill pot along with 5 mm diameter zirconium beads, and the sealed pot was placed on a mill turntable for dispersion to obtain a liquid composition for forming an insulating layer. The pot rotation speed during dispersion was 35 rpm, and dispersion was considered complete when the viscosity change reached a steady state.

[0179] <Preparation of negative electrode> A liquid composition for forming a negative electrode composite layer was prepared by mixing 97 parts of graphite (manufactured by JFE Chemical Corporation, model number BTM-DMP), 1 part by mass of a thickener (carboxymethyl cellulose, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., model number CELLOGEN HS-6), 2 parts by mass of polymeric styrene butadiene rubber (manufactured by JSR, model number TRD-104A), and 100 parts by mass of water as a solvent. The liquid composition for forming a negative electrode composite layer was applied to a copper negative electrode substrate (manufactured by Furukawa Electric Co., Ltd., model number NC-WS, foil thickness 10 μm) and then dried to obtain a coating amount per unit area (area density) of 9 mg / cm on one side. 2 The thickness of the negative electrode was 216 μm, and the volume density of the negative electrode was 0.91 g / cm 3 It was. Next, the volume density of the negative electrode was measured using a roll press machine until it reached 1.6 g / cm 3 The negative electrode was then pressed to obtain a negative electrode.

[0180] <Preparation of positive electrode> The positive electrode active material was 92 parts lithium nickel oxide (NCM) (Beijing Dangsheng Materials Technology Co., Ltd., model ME6E), the conductive material was 3 parts Ketjenblack (Lion Corporation, model 600JD), and the electrode composite layer binder was 5 parts PVDF (polyvinylidene fluoride, Solvay, model Solef5130). These were dispersed in N-methylpyrrolidone (NMP) (Mitsubishi Chemical Corporation) to prepare a slurry. This slurry was applied to an aluminum positive electrode substrate (UACJ Corporation, model 1N30) and then dried to a coating amount per unit area (area density) of 15.0 mg / cm. 2 Next, the volume density of the positive electrode was reduced to 3.4 g / cm using a roll press. 3 The resultant was compression molded to obtain a positive electrode.

[0181] <Formation of insulating layer> The insulating layer-forming liquid composition was applied to the substrate (positive electrode composite layer, separator, and base). The coating was performed using an inkjet or bar coater, and the dispersion medium was then evaporated in a hot air drying oven heated to 120°C to form an insulating layer with an average thickness of approximately 3 μm (insulating layer-forming liquid composition primary drying step). Subsequently, the insulating layer-forming liquid composition was heated to 120°C under a reduced pressure of 0.1 MPa (measured by a differential pressure gauge) in a vacuum oven, and stored for 12 hours to perform the insulating layer-forming liquid composition secondary drying step.

[0182] (Examples 2 to 199, Comparative Examples 1 to 5) Liquid compositions for forming an insulating layer and insulating layers were prepared in the same manner as in Example 1, except that the formulations of the liquid compositions for forming an insulating layer were changed as shown in Tables 1 to 15.

[0183] The details of the materials used in each example and each comparative example are as follows.

[0184] -Insulating inorganic particles- CT-3000LSSG (manufactured by Almatis) BMB-07 (Kawai Coal Industries Co., Ltd.)

[0185] -Dispersant- SC-0505K (NOF Corporation) SC-0708A (NOF Corporation) AKM0531 (NOF Corporation) AKM0531 (60% aqueous solution) (AKM0531 diluted with water to a concentration of 60%, manufactured by NOF Corporation) HKM-50A (NOF Corporation)

[0186] -Comparative dispersant- CMCNa (Carboxymethylcellulose sodium, manufactured by Kanto Chemical Co., Ltd.)

[0187] -Crosslinking agent- DBE-C25 (Gelest) K-FLEX UD-320-100 (Kings Industries) epan740 (Dai-ichi Kogyo Seiyaku Co., Ltd., R2: poloxamer) K-FLEX 148 (Kings Industries) Jeffamine ED-2003 (Huntsman)

[0188] -Binder- Kynar Aquatec ARC (manufactured by Arkema) Kynar Aquatec CRX (manufactured by Arkema) Kynar Flex LBG-2200LX (Arkema) Lumiflon FE4300 (AGC Corporation) MPT-N8 (Mitsubishi Pencil Co., Ltd.) BM-900B (manufactured by Zeon Corporation) Kynar Aquatec FMA-12 (Arkema)

[0189] -Comparison binder- Polymaron 1343S (manufactured by Arakawa Chemical Industries, Ltd.) AC Polyethylene 629 (Honeywell)

[0190] -Dispersion medium material- EL (Ethyl lactate, manufactured by Kanto Chemical Co., Ltd.) ·H2O sol.(H2O:IPA:PG=2:1:1 solution)

[0191] [Table 1]

[0192] [Table 2]

[0193] [Table 3]

[0194] [Table 4]

[0195] [Table 5]

[0196] [Table 6]

[0197] [Table 7]

[0198] [Table 8]

[0199] [Table 9]

[0200] [Table 10]

[0201] [Table 11]

[0202] [Table 12]

[0203] [Table 13]

[0204] [Table 14]

[0205] [Table 15]

[0206] The median diameter D50 and viscosity of each of the obtained liquid compositions for forming an insulating layer were measured.

[0207] [Measurement of median diameter D50] The median diameter D50 of each insulating layer-forming liquid composition was measured using a concentrated particle size analyzer (Otsuka Electronics, FPAR-1000) and evaluated according to the following evaluation criteria. If the D50 value was unstable, the insulating layer-forming liquid composition was diluted appropriately. The results are shown in Tables 16 to 18. <Evaluation criteria for median diameter D50> ○: Median diameter D50 is 300 nm or more and less than 1,000 nm ×: Median diameter D50 is 1,000 nm or more

[0208] [Viscosity measurement] After stabilizing the temperature of each insulating layer-forming liquid composition at 25°C, the viscosity was measured using an E-type viscometer (Toki Sangyo, TVE-25L) at a rotor rotation speed of 100 rpm, and evaluated according to the following evaluation criteria. The results are shown in Tables 16 to 18. <Viscosity evaluation criteria> ○: Viscosity is less than 12 mPa·s ×: Viscosity is 12 mPa·s or more

[0209] [Evaluation of ejection properties] The dischargeability of each insulating layer-forming liquid composition was evaluated based on the median diameter D50 and the viscosity. The results are shown in Tables 16 to 18. <Evaluation criteria for ejection performance> ○: Both the median diameter D50 and viscosity evaluations are "○" △: Either the median diameter D50 or the viscosity is evaluated as "×" ×: Both the median diameter D50 and the viscosity were evaluated as "×".

[0210] The storage stability of each of the obtained liquid compositions for forming an insulating layer was evaluated. [Evaluation of storage stability] After preparing each liquid composition for forming an insulating layer, the viscosity and particle size were evaluated and recorded as the initial properties. After one day of stirring and storage, the viscosity and particle size of each liquid composition for forming an insulating layer were evaluated again and recorded as the post-storage properties. The initial properties were compared with the post-storage properties, and a rating was made based on the following evaluation criteria. The viscosity and particle size were evaluated using the same methods as in [Measurement of viscosity] and [Measurement of median diameter D50]. The results are shown in Tables 16 to 18. <Evaluation criteria for storage stability> 〇: No change in initial properties or properties after storage △: In the physical properties after storage, either the median diameter D50 or the viscosity evaluation is "×" ×: In the physical properties after storage, both the median diameter D50 and the viscosity were evaluated as "×".

[0211] [Table 16]

[0212] [Table 17]

[0213] [Table 18]

[0214] The abrasion strength and peel strength of each of the obtained insulating layers were measured.

[0215] [Evaluation of abrasion strength of insulating layer] After the primary drying, the surface of the insulating layer was checked for adhesion of particles when touched with a finger wearing rubber gloves (BioLab Fit Gloves (powder-free)) at a speed of 10 cm per second. Evaluation was performed based on the following evaluation criteria. The results are shown in Tables 19 to 22. <Evaluation criteria for abrasion strength> 〇: No particles adhere to rubber gloves ×: Particles adhere to rubber gloves

[0216] [Evaluation of the peel strength of the insulating layer] The evaluation device used was a light-load type adhesive / coating peeling analyzer (VPA-3S, manufactured by Kyowa Interface Science Co., Ltd.) and 18 mm wide tape (cellophane tape, manufactured by Nitto Corporation). The tape was attached to the insulating layer and peeled at a peel angle of 90 degrees and a peeling speed of 30 mm / min, and the average value of the load applied to the load cell was read. The insulating layer after primary drying and the insulating layer after secondary drying were evaluated separately. Evaluation was based on the following evaluation criteria. The results are shown in Tables 19 to 22. <Evaluation criteria for peel strength of insulation layer after primary drying> ○: Peel strength is 30N / m or more and less than 250N / m ×: Peel strength is less than 30 N / m or 250 N / m or more <Evaluation criteria for peel strength of insulation layer after secondary drying> ○: Peel strength is 100N / m or more ×: Peel strength is less than 100 N / m

[0217] [Table 19]

[0218] [Table 20]

[0219] [Table 21]

[0220] [Table 22]

[0221] The insulating layer-forming liquid compositions of Examples 1 to 198 were all good in viscosity, median diameter, and dischargeability. In the liquid composition for forming an insulating layer of Example 199, the binder did not disperse in the nonaqueous electrolyte, and the liquid composition for forming an insulating layer had a high viscosity. In addition, since the content of the acrylic resin relative to the insulating inorganic particles was high, the liquid composition tended to aggregate, and its storage stability was reduced. The insulating layers of Examples 1 to 199 exhibited reduced abrasion strength when LBG-2200LX and MPT-N8 were used as binders, but were otherwise excellent. The insulating layer-forming liquid composition of Comparative Example 1 used a binder that did not contain fluorine atoms, and therefore aggregation occurred, making it impossible to carry out measurement and evaluation. In Comparative Example 2, since no binder was added, the abrasion strength after primary drying and the peel strength after primary drying did not meet the standards. In Comparative Example 3, the dispersant did not have the structural units represented by the general formulas (1) to (3), and therefore did not dissolve in the non-aqueous electrolyte, the liquid composition for forming an insulating layer thickened, and the particle size distribution deteriorated, so further evaluation was not possible. In Comparative Examples 4 and 5, the insulating layer-forming liquid composition was thickened and the particle size distribution deteriorated because a binder not containing fluorine was used, and therefore further evaluation was not possible.

[0222] (Examples 200 to 222 and Comparative Examples 6 to 12) <Making a lithium-ion battery> Liquid compositions for forming an insulating layer were prepared in the same manner as in Example 1, except that the compositions were changed as shown in Tables 23 and 24.

[0223] [Table 23]

[0224] [Table 24]

[0225] For each insulating layer-forming liquid composition, the median diameter D50, viscosity, dischargeability, and storage stability were measured and evaluated in the same manner as in Example 1. The results are shown in Table 25.

[0226] Electrodes with insulating layers formed using each insulating layer-forming liquid composition and electrodes with opposite polarity were alternately stacked with separators between them to obtain electrode stacks. The electrode stacks were mounted on a laminate, and an electrolyte solution (EC:DMC:EC = 1%:1%:1%, LiPF6 1.5 mol / L, vinylene carbonate (VC) 1%) was poured into them, and the inside was vacuum-sealed to produce each lithium-ion secondary battery. When a separator having an insulating layer formed thereon was used, the separator having an insulating layer formed thereon was sandwiched between the negative electrode and the positive electrode, and these were alternately stacked to obtain an electrode stack. In Comparative Example 12, a lithium ion secondary battery was obtained without forming an insulating layer.

[0227] To evaluate the battery characteristics of the obtained lithium ion battery, an output characteristic test, a float test, and a temperature rise test were carried out. The positive electrode and negative electrode wires of the resulting lithium-ion battery were connected to a charge / discharge tester and charged at a constant current and constant voltage of 4.2 V at a current rate of 0.2 C for 5 hours. After charging, the battery was left in a thermostatic chamber at 40°C for 5 days. The battery was then discharged at a constant current of 0.2 C to 2.5 V. The battery was then charged at a constant current and constant voltage of 4.2 V at a current rate of 0.2 C for 5 hours, followed by a 10-minute break and then discharged at a constant current of 0.2 C to 2.5 V. The discharge capacity at this time was recorded as the initial capacity.

[0228] [Evaluation of output characteristics] The positive and negative electrode leads of the battery whose initial capacity had been measured were connected to a charge / discharge tester and charged at a maximum voltage of 4.2 V and a current rate of 0.2 C for 5 hours. After a 10-minute break, the battery was discharged at a constant current of 0.2 C for 2.5 hours, bringing the lithium-ion battery to a 50% state of charge. Next, the battery was pulsed at current rates of 1 C to 10 C for 10 seconds. The power required to reach a 2.5 V cutoff voltage was calculated from the correlation line between the post-pulse voltage and current value, and the power density was calculated by dividing this by the cell weight. The output characteristics of each lithium-ion battery were evaluated by comparing the output density ratio with that of a lithium-ion battery without an insulating layer on the electrodes, and using the following evaluation criteria. The results are shown in Table 25. <Evaluation criteria for output characteristics> 〇: 97% or more compared to lithium-ion batteries without an insulating layer △: 95% to 97% of lithium-ion batteries without an insulating layer ×: Less than 95% of lithium-ion batteries without an insulating layer

[0229] [Float test] A fully charged lithium-ion secondary battery was placed in a thermostatic chamber set at 60°C and subjected to 4.2V constant voltage charging for 10 days. The cumulative charge capacity [mAh] during constant voltage charging was calculated. The float characteristics were evaluated according to the following criteria. The results are shown in Table 25. <Float test evaluation criteria> 〇: Accumulated charging capacity is 20mAh or less ×: Accumulated charging capacity exceeds 20mAh

[0230] [Temperature rise test] A 4.2V fully charged lithium-ion secondary battery was placed in a thermostatic chamber and left at 30°C for 30 minutes. After that, it was heated to 140°C at a rate of 5°C per minute. Once it reached 140°C, it was held there for 30 minutes before being cooled. The voltage of the lithium-ion secondary battery was measured during the test, and cells whose cell voltage fell below 1V were considered to be short-circuited. Evaluation was based on the following criteria. The results are shown in Table 25. <Evaluation criteria for temperature rise test> 〇: The percentage of short-circuited cells is less than 50% ×: The proportion of short-circuited cells is 50% or more

[0231] [Table 25]

[0232] It can be seen that the batteries obtained using the liquid compositions for forming insulating layers of Examples 200-201, 205-208, 213-216, and 221-222 have insufficient ionic conductivity and poor output characteristics because the content of each material is outside the preferred numerical range. The insulating layer-forming liquid composition of Comparative Example 6 had a low content of dispersant, and the insulating layer-forming liquid composition was poorly dispersed, making it impossible to carry out measurement and evaluation. The insulating layer-forming liquid composition of Comparative Example 7 contained a large amount of dispersant, and the output characteristics were deteriorated, so it did not meet the standard. The insulating layer-forming liquid composition of Comparative Example 8 had a low content of crosslinking agent, and therefore was unable to form a sufficient crosslinked resin, resulting in film peeling during the temperature rise test and failing to meet the standard. The insulating layer-forming liquid composition of Comparative Example 9 contained a large amount of crosslinking agent, and the output characteristics were deteriorated, so that the standard was not met. The insulating layer-forming liquid composition of Comparative Example 10 had a low binder content, and therefore had low peel strength after primary drying, which resulted in film chipping during the cell manufacturing process and did not meet the criteria for the temperature rise test. The insulating layer-forming liquid composition of Comparative Example 11 had a high binder content, and therefore the peel strength after primary drying was excessive, resulting in a deterioration in output characteristics and failing to meet the standards. In Comparative Example 12, the insulating layer was not formed, and therefore the criteria for the float test and the temperature rise test were not met.

[0233] The present invention includes, for example, the following aspects. <1> insulating inorganic particles; a resin containing at least one selected from a structural unit represented by general formula (1), a structural unit represented by general formula (2), and a structural unit represented by general formula (3); A resin containing a structural unit represented by the following general formula (4): A liquid composition for forming an insulating layer, comprising: the content of the resin containing at least one selected from the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (3) is 1% by mass or more and 10% by mass or less with respect to the total amount of the insulating inorganic particles, the content of the resin containing the structural unit represented by the general formula (4) is 0.1 mass % or more and 5 mass % or less with respect to the total amount of the insulating inorganic particles, The insulating layer-forming liquid composition is characterized in that the content of the fluorine atom-containing resin is 1% by mass or more and 8% by mass or less with respect to the total amount of the insulating inorganic particles. [ka] [ka] [ka] [ka] (In the general formulas (1) to (4), * represents a bonding site to an adjacent main chain structural unit; R2 represents at least one selected from polyurethane, polyester, polyethylene oxide, polypropylene oxide, poloxamer, polycarbonate, silicone, polybutadiene, and hydrogenated polybutadiene butane; R3 and R4 represent a hydroxyl group or an amino group; M represents an ammonium salt; and n, m, and l represent integers of 2 to 500.) <2> The resin containing at least one selected from the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (3), and the resin containing the structural unit represented by the general formula (4) are soluble in an electrolyte solvent alone. <1> 1. The liquid composition for forming an insulating layer according to claim 1. <3> The fluorine atom-containing resin is dispersed alone in the electrolyte solvent. <1> or <2> 1. The liquid composition for forming an insulating layer according to claim 1. <4> The resin containing fluorine atoms includes at least one fluororesin selected from PVDF, PVDF-HFP, PTFE, and PEVE. <1> from <3> 1. The liquid composition for forming an insulating layer according to claim 1, wherein the insulating layer is a liquid composition for forming an insulating layer. <5> The resin containing fluorine atoms includes a fluororesin containing PVDF-HFP. <1> from <3> 1. The liquid composition for forming an insulating layer according to claim 1, wherein the insulating layer is a liquid composition for forming an insulating layer. <6> The resin containing a fluorine atom includes an acrylic resin. <1> from <5> 1. The liquid composition for forming an insulating layer according to claim 1, wherein the insulating layer is a liquid composition for forming an insulating layer. <7> The acrylic resin comprises an interpenetrating polymer network. <6> 1. The liquid composition for forming an insulating layer according to claim 1. <8> The content of the fluororesin is 65% by mass or more based on the total amount of the resin containing fluorine atoms, a content of the acrylic resin being 35% by mass or less based on the total amount of the resin containing a fluorine atom; <6> or <7> 1. The liquid composition for forming an insulating layer according to claim 1. <9> the content of the resin containing at least one selected from the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (3) is 1.5 mass % or more and 8 mass % or less with respect to the total amount of the insulating inorganic particles, the content of the resin containing the structural unit represented by the general formula (4) is 0.3 mass % or more and 4 mass % or less with respect to the total amount of the insulating inorganic particles, The content of the resin containing fluorine atoms is 1.5 mass % or more and 7 mass % or less with respect to the total amount of the insulating inorganic particles. <1> from <8> 1. The liquid composition for forming an insulating layer according to claim 1, wherein the insulating layer is a liquid composition for forming an insulating layer. <10> R2 in the general formula (4) is poloxamer. <1> from <9> 1. The liquid composition for forming an insulating layer according to claim 1, wherein the insulating layer is a liquid composition for forming an insulating layer. <11> The insulating inorganic particles are α-alumina or boehmite. <1> from <10> 1. The liquid composition for forming an insulating layer according to claim 1, wherein the insulating layer is a liquid composition for forming an insulating layer. <12> a substrate; an electrode mixture layer provided on a portion of the substrate; an insulating layer covering a boundary between the exposed portion of the substrate and the electrode mixture layer, The insulating layer is insulating inorganic particles; a resin containing fluorine atoms; a crosslinked resin containing at least one selected from a structural unit represented by the following general formula (5) and a structural unit represented by the following general formula (6); The electrode is characterized by comprising: [ka] [ka] (In the general formulas (5) and (6), * represents a bonding site with an adjacent main chain structural unit, R represents at least one structure of polyethylene oxide, polypropylene oxide, polycarbonate, silicone, polybutadiene, or hydrogenated polybutadiene butane, and o, p, q, and r represent integers of 2 to 500.) <13> The crosslinked resin is formed by a reaction between a resin containing at least one selected from a structural unit represented by the following general formula (1), a structural unit represented by the following general formula (2), and a structural unit represented by the following general formula (3), and a resin containing a structural unit represented by the following general formula (4): <12> The electrode is described in [ka] [ka] [ka] [ka] (In the general formulas (1) to (4), * represents a bonding site to an adjacent main chain structural unit; R2 represents at least one selected from polyurethane, polyester, polyethylene oxide, polypropylene oxide, poloxamer, polycarbonate, silicone, polybutadiene, and hydrogenated polybutadiene butane; R3 and R4 represent a hydroxyl group or an amino group; M represents an ammonium salt; and n, m, and l represent integers of 2 to 500.) <14> The resin containing fluorine atoms includes a fluororesin including PVDF-HFP and an acrylic resin. <12> or <13> The electrode is described in <15> the acrylic resin comprises an interpenetrating polymer network; The content of the fluororesin is 65% by mass or more based on the total amount of the resin containing fluorine atoms, the content of the acrylic resin is 35% by mass or less based on the total amount of the resin containing a fluorine atom, the cross-linked resin is unevenly distributed on the surface of the insulating layer; <14> The electrode is described in <16> the cross-linked resin is unevenly distributed on the surface of the insulating layer; <12> from <15> The electrode is any one of the above. <17> The insulating inorganic particles are α-alumina or boehmite. <12> from <16> The electrode is any one of the above. <18> A method for manufacturing an electrode including an insulating layer forming step, The insulating layer forming step is performed by forming an insulating layer on the substrate and the electrode mixture layer provided on a part of the substrate so as to cover a boundary between a substrate exposed portion where the substrate is exposed and the electrode mixture layer. <1> from <11> 10. A method for manufacturing an electrode, comprising the step of applying the liquid composition for forming an insulating layer according to any one of the above items. <19> <12> from <17> 1. An electrochemical device comprising the electrode according to any one of the above items. <20> A separator having a separator and an insulating layer provided on the separator, The insulating layer is insulating inorganic particles; a resin containing fluorine atoms; a crosslinked resin containing at least one selected from a structural unit represented by the following general formula (5) and a structural unit represented by the following general formula (6); The separator is characterized by comprising: [ka] [ka] (In the general formulas (5) and (6), * represents a bonding site to an adjacent main chain structural unit, R represents at least one structure selected from the group consisting of polyurethane, polyester, polyethylene oxide, polypropylene oxide, poloxamer, polycarbonate, silicone, polybutadiene, and hydrogenated polybutadiene butane, and o, p, q, and r represent integers of 2 to 500.) <21> The crosslinked resin is formed by a reaction between a resin containing at least one selected from a structural unit represented by the following general formula (1), a structural unit represented by the following general formula (2), and a structural unit represented by the following general formula (3), and a resin containing a structural unit represented by the following general formula (4): <20> 1. The separator according to claim 1. [ka] [ka] [ka] [ka] (In the general formulas (1) to (4), * represents a bonding site to an adjacent main chain structural unit; R2 represents at least one selected from polyurethane, polyester, polyethylene oxide, polypropylene oxide, poloxamer, polycarbonate, silicone, polybutadiene, and hydrogenated polybutadiene butane; R3 and R4 represent a hydroxyl group or an amino group; M represents an ammonium salt; and n, m, and l represent integers of 2 to 500.) <22> A method for manufacturing a separator including an insulating layer forming step, The insulating layer forming step includes forming a separator on the separator. <1> from <11> The method for producing a separator includes a step of applying the liquid composition for forming an insulating layer according to any one of the above items.

[0234] <1> from <11> The liquid composition for forming an insulating layer according to any one of <12> from <17> The electrode according to any one of <18> A method for producing an electrode according to the present invention <19> The electrochemical element according to <20> or <21> The separator according to claim 1, <22> The method for producing a separator described above can solve the various problems encountered in the prior art and achieve the object of the present invention. [Explanation of symbols]

[0235] 1 Base 11 Exposed base part 2 Electrode composite layer 3. Insulation layer [Prior art documents] [Patent documents]

[0236] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-277386 [Patent Document 2] Patent No. 7085147

Claims

1. insulating inorganic particles; a resin containing at least one selected from a structural unit represented by the following general formula (1), a structural unit represented by the following general formula (2), and a structural unit represented by the following general formula (3); a resin containing a structural unit represented by the following general formula (4), A liquid composition for forming an insulating layer, comprising: the content of the resin containing at least one selected from the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (3) is 1 mass % or more and 10 mass % or less with respect to the total amount of the insulating inorganic particles, the content of the resin containing the structural unit represented by the general formula (4) is 0.1 mass % or more and 5 mass % or less with respect to the total amount of the insulating inorganic particles, The liquid composition for forming an insulating layer, wherein the content of the fluorine atom-containing resin is 1% by mass or more and 8% by mass or less based on the total amount of the insulating inorganic particles. 【Chemical 1】 【Chemistry 2】 【Chemistry 3】 【Chemistry 4】 (In the general formulas (1) to (4), * represents a bonding site to an adjacent main chain structural unit; R2 represents at least one selected from polyurethane, polyester, polyethylene oxide, polypropylene oxide, poloxamer, polycarbonate, silicone, polybutadiene, and hydrogenated polybutadiene butane; R3 and R4 represent a hydroxyl group or an amino group; M represents an ammonium salt; and n, m, and l represent integers of 2 to 500.)

2. 2. The insulating layer-forming liquid composition according to claim 1, wherein the resin containing at least one selected from the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (3), and the resin containing the structural unit represented by the general formula (4) are independently soluble in an electrolyte solvent.

3. The insulating layer-forming liquid composition according to claim 1 or 2, wherein the fluorine atom-containing resin is dispersed alone in an electrolyte solvent.

4. 2. The insulating layer-forming liquid composition according to claim 1, wherein the resin containing fluorine atoms includes at least one fluororesin selected from the group consisting of PVDF, PVDF-HFP, PTFE, and PEVE.

5. 2. The insulating layer-forming liquid composition according to claim 1, wherein the resin containing fluorine atoms comprises a fluororesin containing PVDF-HFP.

6. The insulating layer-forming liquid composition according to claim 4 or 5, wherein the resin containing fluorine atoms includes an acrylic resin.

7. The liquid composition for forming an insulating layer according to claim 6 , wherein the acrylic resin includes an interpenetrating polymer network structure.

8. The content of the fluororesin is 65% by mass or more based on the total amount of the resin containing fluorine atoms, 7. The insulating layer-forming liquid composition according to claim 6, wherein the content of the acrylic resin is 35% by mass or less based on the total amount of the resin containing a fluorine atom.

9. the content of the resin containing at least one selected from the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (3) is 1.5 mass % or more and 8 mass % or less with respect to the total amount of the insulating inorganic particles, the content of the resin containing the structural unit represented by the general formula (4) is 0.3 mass % or more and 4 mass % or less with respect to the total amount of the insulating inorganic particles, 3. The insulating layer-forming liquid composition according to claim 1, wherein the content of the fluorine-containing resin is 1.5% by mass or more and 7% by mass or less with respect to the total amount of the insulating inorganic particles.

10. 3. The liquid composition for forming an insulating layer according to claim 1, wherein R2 in the general formula (4) is a poloxamer.

11. 3. The insulating layer-forming liquid composition according to claim 1, wherein the insulating inorganic particles are α-alumina or boehmite.

12. a substrate; an electrode mixture layer provided on a portion of the substrate; an insulating layer covering a boundary between the exposed portion of the substrate and the electrode mixture layer, The insulating layer is insulating inorganic particles; a resin containing fluorine atoms; a crosslinked resin containing at least one selected from a structural unit represented by the following general formula (5) and a structural unit represented by the following general formula (6); An electrode comprising: 【Chemistry 5】 【Chemistry 6】 (In the general formulas (5) and (6), * represents a bonding site to an adjacent main chain structural unit, R represents at least one structure selected from the group consisting of polyurethane, polyester, polyethylene oxide, polypropylene oxide, poloxamer, polycarbonate, silicone, polybutadiene, and hydrogenated polybutadiene butane, and o, p, q, and r represent integers of 2 to 500.)

13. 13. The electrode according to claim 12, wherein the crosslinked resin is formed by a reaction between a resin containing at least one selected from a structural unit represented by the following general formula (1), a structural unit represented by the following general formula (2), and a structural unit represented by the following general formula (3), and a resin containing a structural unit represented by the following general formula (4): 【Chemistry 7】 【Chemistry 8】 【Chemistry 9】 【Chemistry 10】 (In the general formulas (1) to (4), * represents a bonding site to an adjacent main chain structural unit; R2 represents at least one selected from polyurethane, polyester, polyethylene oxide, polypropylene oxide, poloxamer, polycarbonate, silicone, polybutadiene, and hydrogenated polybutadiene butane; R3 and R4 represent a hydroxyl group or an amino group; M represents an ammonium salt; and n, m, and l represent integers of 2 to 500.)

14. 14. The electrode according to claim 12, wherein the resin containing fluorine atoms comprises a fluororesin containing PVDF-HFP and an acrylic resin.

15. the acrylic resin comprises an interpenetrating polymer network; The content of the fluororesin is 65% by mass or more based on the total amount of the resin containing fluorine atoms, the content of the acrylic resin is 35% by mass or less based on the total amount of the resin containing a fluorine atom, The electrode according to claim 14 , wherein the cross-linked resin is unevenly distributed on the surface of the insulating layer.

16. The electrode according to claim 12 or 13, wherein the cross-linked resin is unevenly distributed on the surface of the insulating layer.

17. 14. The electrode according to claim 12, wherein the insulating inorganic particles are α-alumina or boehmite.

18. A method for manufacturing an electrode including an insulating layer forming step, 3. A method for manufacturing an electrode, wherein the insulating layer forming step includes a step of applying the insulating layer forming liquid composition according to claim 1 to a substrate and an electrode mixture layer provided on a portion of the substrate so as to cover a boundary between an exposed portion of the substrate where the substrate is exposed and the electrode mixture layer.

19. An electrochemical device comprising the electrode according to claim 12 or 13.

20. A separator having a separator and an insulating layer provided on the separator, The insulating layer is insulating inorganic particles; a resin containing fluorine atoms; a crosslinked resin containing at least one selected from a structural unit represented by the following general formula (5) and a structural unit represented by the following general formula (6), A separator comprising: 【Chemistry 11】 【Chemistry 12】 (In the general formulas (5) and (6), * represents a bonding site to an adjacent main chain structural unit, R represents at least one structure selected from the group consisting of polyurethane, polyester, polyethylene oxide, polypropylene oxide, poloxamer, polycarbonate, silicone, polybutadiene, and hydrogenated polybutadiene butane, and o, p, q, and r represent integers of 2 to 500.)

21. 21. The separator according to claim 20, wherein the crosslinked resin is formed by a reaction between a resin containing at least one selected from a structural unit represented by the following general formula (1), a structural unit represented by the following general formula (2), and a structural unit represented by the following general formula (3), and a resin containing a structural unit represented by the following general formula (4): 【Chemistry 13】 【Chemistry 14】 【Chemistry 15】 【Chemistry 16】 (In the general formulas (1) to (4), * represents a bonding site to an adjacent main chain structural unit; R2 represents at least one selected from polyurethane, polyester, polyethylene oxide, polypropylene oxide, poloxamer, polycarbonate, silicone, polybutadiene, and hydrogenated polybutadiene butane; R3 and R4 represent a hydroxyl group or an amino group; M represents an ammonium salt; and n, m, and l represent integers of 2 to 500.)

22. A method for manufacturing a separator including an insulating layer forming step, 3. A method for producing a separator, wherein the insulating layer forming step includes a step of applying the insulating layer forming liquid composition according to claim 1 onto a separator.

Images