WO2019230219A1 - 接着性組成物、セパレータ構造体、電極構造体、非水電解質二次電池およびその製造方法 - Google Patents
接着性組成物、セパレータ構造体、電極構造体、非水電解質二次電池およびその製造方法 Download PDFInfo
- Publication number
- WO2019230219A1 WO2019230219A1 PCT/JP2019/016153 JP2019016153W WO2019230219A1 WO 2019230219 A1 WO2019230219 A1 WO 2019230219A1 JP 2019016153 W JP2019016153 W JP 2019016153W WO 2019230219 A1 WO2019230219 A1 WO 2019230219A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- vinylidene fluoride
- mass
- separator
- adhesive resin
- adhesive composition
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/46—Separators, membranes or diaphragms characterised by their combination with electrodes
- H01M50/461—Separators, membranes or diaphragms characterised by their combination with electrodes with adhesive layers between electrodes and separators
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/443—Particulate material
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
- C09J11/02—Non-macromolecular additives
- C09J11/06—Non-macromolecular additives organic
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J127/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Adhesives based on derivatives of such polymers
- C09J127/02—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Adhesives based on derivatives of such polymers not modified by chemical after-treatment
- C09J127/12—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Adhesives based on derivatives of such polymers not modified by chemical after-treatment containing fluorine atoms
- C09J127/16—Homopolymers or copolymers of vinylidene fluoride
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/058—Construction or manufacture
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/403—Manufacturing processes of separators, membranes or diaphragms
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/411—Organic material
- H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
- H01M50/426—Fluorocarbon polymers
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/46—Separators, membranes or diaphragms characterised by their combination with electrodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Definitions
- the present invention relates to an adhesive composition, a separator structure, an electrode structure, a nonaqueous electrolyte secondary battery, and a method for producing the same.
- Non-aqueous electrolyte secondary batteries such as lithium ion secondary batteries have high voltage and high energy density, and are therefore used as power sources for various applications such as mobile electronic devices such as smartphones and electric vehicles.
- the lithium ion secondary battery has a positive electrode, a negative electrode, a separator disposed between them, and an electrolytic solution.
- the separator functions as an ion passage in the battery and has a function of preventing a short circuit due to direct contact between the positive electrode and the negative electrode.
- an adhesive composition layer is provided on the surface of the separator or the electrode, and the separator and the electrode are bonded via the adhesive composition layer, so that the oxidation resistance of the separator and the separator and the electrode It has been studied to improve the adhesion.
- separator having an adhesive composition layer for example, adhesion of a coating liquid obtained by mixing a dispersion liquid containing copolymer particles of vinylidene fluoride (VDF) and hexafluoropropylene (HFP) and a CMC aqueous solution.
- a separator having a composition layer is disclosed (for example, Patent Document 1).
- a battery having a separator or an electrode having such an adhesive composition layer may be exposed to a high temperature environment. Therefore, it is required that the adhesiveness between the separator and the electrode is not lowered even in a high temperature environment.
- a laminate cell is taken as an example.
- the allowable heating or hot pressing temperature range is as wide as possible.
- the present invention has been made in view of the above circumstances, and can maintain high adhesion between a separator and an electrode even when exposed to high temperatures, and includes an adhesive resin having a wide process window.
- An object is to provide a composition. Moreover, it aims at providing the separator structure using the said adhesive composition, an electrode structure, a nonaqueous electrolyte secondary battery, and its manufacturing method.
- the adhesive composition of the nonaqueous electrolyte secondary battery of the present invention for solving the above problems is an adhesive composition containing an adhesive resin provided on the surface of the separator or electrode of the nonaqueous electrolyte secondary battery.
- the adhesive resin includes at least one vinylidene fluoride copolymer (a) including a structural unit derived from vinylidene fluoride and a structural unit derived from a monomer copolymerizable with the vinylidene fluoride.
- NMP N-methyl-2-pyrrolidone
- the solution viscosity (A) when the adhesive resin is dissolved in acetone so that the concentration in the solution is 10% by mass is 350 to 20000 mPa ⁇ s, and the adhesive resin is a solution.
- the concentration inside is 5
- the ratio of the solution viscosity for the solution viscosity (B) when dissolved in NMP such that the amount% (A) (A) / (B) is 1 to 15.
- the separator structure of the present invention has a separator and an adhesive composition layer obtained using the adhesive composition of the present invention provided on at least one surface thereof.
- the electrode structure of the present invention includes a current collector, an electrode having an electrode active material layer containing an electrode active material provided on the current collector, and a book provided on the surface of the electrode active material layer. And an adhesive composition layer obtained using the adhesive composition of the invention.
- the nonaqueous electrolyte secondary battery of the present invention is provided in at least one of a positive electrode, a negative electrode, a separator disposed therebetween, between the separator and the positive electrode, and between the separator and the negative electrode. And an adhesive composition layer obtained using the adhesive composition of the present invention.
- the method for producing a non-aqueous electrolyte secondary battery of the present invention includes a positive electrode, a negative electrode, a separator disposed therebetween, at least one between the separator and the positive electrode, and between the separator and the negative electrode. And a step of obtaining a laminate having an adhesive composition layer obtained by using the adhesive composition of the present invention, and the laminate through the adhesive resin composition layer and the separator. Adhering the positive electrode and / or adhering the separator and the negative electrode.
- the adhesive composition which can maintain the high adhesiveness of a separator and an electrode, and has a wide process window in a heating or a hot press process, and its use
- the separator structure, the electrode structure, the battery, and the method for producing the adhesive composition can be provided.
- the high adhesion between the separator and the electrode means that “the component of the adhesive composition layer provided between the separator and the electrode does not dissolve in the electrolyte even at a certain temperature or higher, It is thought that it is obtained by “remaining in”, and “the component of the adhesive composition layer has a high elastic modulus”.
- the wide process window is “when the components of the adhesive composition layer are not dissolved in the electrolyte even when they are exposed to a high temperature (such as a heating or hot pressing process), and the separator and electrode It is considered effective to remain between.
- a polymer having low solubility in an electrolytic solution usually has a low solubility in NMP and a high solubility in acetone. If the solubility in NMP is low, the turbidity when dissolved in NMP tends to be high. If the solubility in acetone is high, the solution viscosity (A) when dissolved in acetone tends to be high.
- the present inventors have found that when the adhesive resin containing the vinylidene fluoride copolymer (a) is dissolved in NMP and has a turbidity of 2 or more and 95 or less, the solubility in the electrolyte solution If the solution viscosity (A) is 350 to 20000 mPa ⁇ s when dissolved in acetone, it is possible to partially control the affinity of the adhesive resin for the electrolyte solution. It was found that the solubility of the adhesive resin in the electrolyte solution can be lowered (rement (i)).
- a polymer having a high elastic modulus usually has a high solubility in NMP and a low solubility in acetone. If the solubility in NMP is high, the solution viscosity (B) when dissolved in NMP tends to be high. If the solubility in acetone is low, the solution viscosity (A) when dissolved in acetone tends to be low.
- the inventors of the present invention have found that the ratio of the solution viscosity (A) of the acetone solution and the solution viscosity (B) of the NMP solution (A) / adhesive resin containing the vinylidene fluoride copolymer (a) / It was found that by setting (B) to be 1 or more and 15 or less, a high elastic modulus and a low solubility in an electrolyte solution can be achieved in a balanced manner (requirement (ii)).
- the adhesive resin containing the vinylidene fluoride copolymer (a) and satisfying the requirements of i) and ii) can have a low solubility in the electrolytic solution and a high elastic modulus.
- the turbidity when the adhesive resin is dissolved in NMP is 2 or more and 95 or less, and the solution viscosity (A) when the adhesive resin is dissolved in acetone is 350 to 20000 mPa ⁇ s.
- the ratio (A) / (B) of the solution viscosity (A) to the solution viscosity (B) when the adhesive resin is dissolved in NMP is 1 or more and 15 or less.
- the adhesive resin is “mixed” in the solvent, whereas when the adhesive resin is only partially dissolved in the solvent, as in the case where all of the adhesive resin is dissolved, The solution is called “dissolved”, and the mixed solution is called “solution”.
- the turbidity and solution viscosity (B) when the adhesive resin containing the vinylidene fluoride copolymer (a) is dissolved in NMP, and the solution viscosity (A) when dissolved in acetone are vinylidene fluoride.
- the molecular weight and branching amount of the copolymer (a), the content of monomers (HFP and CTFE) and crosslinkable monomers copolymerizable with vinylidene fluoride in the vinylidene fluoride copolymer (a) and their distribution It can be adjusted by the content ratio of the vinylidene fluoride copolymer (a) in the adhesive resin, alkali treatment to the adhesive resin, and the like.
- a monomer copolymerizable with vinylidene fluoride in the vinylidene fluoride copolymer (a) ( It is preferable to increase the content of HFP or CTFE) or the crosslinkable monomer, control the distribution, increase the molecular weight or branching amount of the vinylidene fluoride copolymer (a), and perform an alkali treatment on the adhesive resin.
- the viscosity ratio (A) / (B) of ii) 15 or less for example, the monomer (HFP or CTFE) copolymerizable with vinylidene fluoride or the content of the crosslinkable monomer is increased. It is preferable that the molecular weight and the branching amount of the vinylidene fluoride copolymer (a) are not excessively increased, and that the alkali treatment of the adhesive resin is not performed excessively.
- the positive electrode often includes a vinylidene fluoride polymer as a binder
- the negative electrode often includes a resin different from the vinylidene fluoride polymer, such as carboxymethyl cellulose (CMC), as a binder.
- CMC carboxymethyl cellulose
- the adhesive resin of the present invention and the adhesive composition containing the same satisfying the requirements of i) and ii) can maintain high adhesiveness between the separator and the negative electrode even at high temperatures, and have a process window. Can be wide. The present invention has been made based on such knowledge.
- Adhesive composition contains adhesive resin at least.
- Adhesive Resin contains at least the vinylidene fluoride copolymer (a).
- the vinylidene fluoride copolymer (a) includes a structural unit derived from vinylidene fluoride and a structural unit derived from a monomer copolymerizable with vinylidene fluoride.
- Examples of monomers copolymerizable with vinylidene fluoride include fluorine monomers, hydrocarbon monomers, monomers having hydrogen-bonding polar functional groups (preferably containing carboxyl groups) that can be copolymerized with vinylidene fluoride Monomer).
- fluorine-based monomers copolymerizable with vinylidene fluoride examples include fluorine-containing compounds such as vinyl fluoride, trifluoroethylene, tetrafluoroethylene, hexafluoroethylene, chlorotrifluoroethylene (CTFE), and hexafluoropropylene (HFP). Alkyl vinyl compounds are included.
- hydrocarbon monomers copolymerizable with vinylidene fluoride examples include ethylene, propylene and the like.
- carboxyl group-containing monomers copolymerizable with vinylidene fluoride examples include unsaturated monobasic acids such as acrylic acid, methacrylic acid, 2-carboxyethyl acrylate and 2-carboxyethyl methacrylate; unsaturated monomers such as maleic acid and citraconic acid.
- Saturated dibasic acids Saturated dibasic acids; monoesters of unsaturated dibasic acids such as maleic acid monomethyl ester, maleic acid monoethyl ester, citraconic acid monomethyl ester, citraconic acid monoethyl ester, acryloyloxyethyl succinic acid, acryloyloxyproprusuccinic acid , Methacryloyloxyethyl succinic acid, and methacryloyloxypropyl succinic acid.
- monoesters of unsaturated dibasic acids such as maleic acid monomethyl ester, maleic acid monoethyl ester, citraconic acid monomethyl ester, citraconic acid monoethyl ester, acryloyloxyethyl succinic acid, acryloyloxyproprusuccinic acid , Methacryloyloxyethyl succinic acid, and methacryloyloxypropyl succinic acid.
- a fluorine-based monomer is preferable, tetrafluoroethylene, chlorotrifluoroethylene and hexafluoropropylene are preferable, and hexafluoropropylene is more preferable.
- the content of the structural unit derived from the vinylidene fluoride in the vinylidene fluoride copolymer (a) and the content of the structural unit derived from the monomer copolymerizable with the vinylidene fluoride are the forms of the adhesive resin. Will be described later in detail.
- the vinylidene fluoride copolymer (a) may be cross-linked from the viewpoint of further lowering the solubility in NMP and increasing the adhesive strength with the surface of the electrode. That is, the vinylidene fluoride copolymer (a) is not only a vinylidene fluoride or a monomer copolymerizable with vinylidene fluoride, but also a crosslinkable fluorine-containing alkylvinyl compound (hereinafter also simply referred to as “crosslinkable monomer”). ) May further be included.
- crosslinkable monomer a polyfunctional monomer may be used, and after obtaining an uncrosslinked copolymer, a crosslinking reaction may be further performed using the polyfunctional monomer.
- crosslinkable monomer examples include perfluorodivinyl ether and perfluoroalkylene divinyl ether.
- perfluoroalkylene divinyl ether two vinyl ether groups in which all hydrogen atoms are substituted with fluorine atoms are bonded with a linear or branched divalent perfluoroalkylene group having 1 to 6 carbon atoms. A compound having a different structure can be obtained.
- the content of the structural unit derived from the crosslinkable monomer in the vinylidene fluoride copolymer (a) is less than 5% by mass with respect to the total amount of all structural units constituting the vinylidene fluoride copolymer (a). It is preferably 0.5 to 4% by mass, more preferably 1.2 to 3% by mass.
- the form of the adhesive resin is not particularly limited, but is preferably in the form of particles from the viewpoint of forming a porous adhesive composition layer when water is used as a dispersion medium.
- the form of the adhesive resin particles is not particularly limited, but the above-mentioned requirements i) and ii) (turbidity of NMP solution, solution viscosity (A) of acetone solution, and viscosity ratio (A) / (B)) From the viewpoint of making it easy to satisfy, (1) a core part (or shell part) made of a vinylidene fluoride copolymer (a) and a different monomer copolymerizable with vinylidene fluoride than (a) Core-shell type particles containing a shell part (or core part) made of a vinylidene fluoride polymer (b) with a low content of structural units, or (2) inclined particles made of a vinylidene fluoride copolymer (a) It is preferable that
- the core-shell type particle containing the vinylidene fluoride copolymer (a) is composed of a core part made of the vinylidene fluoride copolymer (a) and a vinylidene fluoride polymer (b) different from the core part. And may have a core part made of a vinylidene fluoride polymer (b) and a shell part made of a vinylidene fluoride copolymer (a).
- the viscosity tends to increase when the content of the structural unit derived from the monomer copolymerizable with vinylidene fluoride is large, the structural unit derived from the monomer copolymerizable with vinylidene fluoride.
- the vinylidene fluoride polymer (b) with a small content of bis constitutes the shell part from the viewpoint of improving the stability during coating and winding. That is, a core-shell type particle having a core part made of a vinylidene fluoride copolymer (a) and a shell part made of a vinylidene fluoride polymer (b) different from the core part is preferable.
- the total amount of the structural unit derived from vinylidene fluoride in the vinylidene fluoride copolymer (a) constituting the core part and the structural unit derived from the monomer copolymerizable with vinylidene fluoride is 100% by mass.
- the content of the structural unit derived from vinylidene fluoride in the vinylidene fluoride copolymer (a) is preferably 20 to 70% by mass, more preferably 30 to 60% by mass, More preferably, it is 30 to 50% by mass.
- the content of the structural unit derived from vinylidene fluoride is a certain level or more, it is easy to increase the solution viscosity (B) of the NMP solution of the core-shell type particles containing the vinylidene fluoride copolymer (a), and the solution viscosity of the acetone solution It is easy to lower (A).
- the viscosity ratio (A) / (B) is easily set to a certain value or less, and the elastic modulus of the core-shell type particles containing the vinylidene fluoride copolymer (a) is easily increased.
- the content of the structural unit derived from the monomer copolymerizable with vinylidene fluoride in the vinylidene fluoride copolymer (a) is preferably 30 to 80% by mass, and preferably 40 to 70% by mass. More preferred is 50 to 70% by mass.
- the turbidity of the NMP solution of the particles containing the vinylidene fluoride copolymer (a) and the viscosity of the acetone solution (A ) Is easy to increase.
- grains containing a vinylidene fluoride copolymer (a) is easy to be made low.
- the solution viscosity (B of the core-shell type particle containing the vinylidene fluoride copolymer (a) (B) ) Does not become too low and the solution viscosity (A) of the acetone solution does not become too high, the viscosity ratio (A) / (B) can be easily set to a certain value or less. Thereby, the elastic modulus of the core-shell type particles containing the vinylidene fluoride copolymer (a) does not become too low.
- the vinylidene fluoride copolymer (a) may be cross-linked. Further, from the viewpoint of not impairing the elastic modulus of the core-shell type particles, the vinylidene fluoride copolymer (a) may not be crosslinked.
- the vinylidene fluoride polymer (b) constituting the shell part contains at least a structural unit derived from vinylidene fluoride.
- the content of structural units derived from vinylidene fluoride in the vinylidene fluoride polymer (b) may be greater than the content of structural units derived from vinylidene fluoride in the vinylidene fluoride copolymer (a). preferable. Specifically, the content of the structural unit derived from vinylidene fluoride in the vinylidene fluoride polymer (b) is described later with the structural unit derived from vinylidene fluoride in the vinylidene fluoride polymer (b).
- the total amount of structural units derived from monomers copolymerizable with any vinylidene fluoride is 100% by mass, it is preferably 80% by mass or more, more preferably 90% by mass or more, More preferably, it is 95 mass% or more, and may be 100 mass%.
- the solution viscosity of the NMP solution of the core-shell type particles containing the vinylidene fluoride copolymer (a) Since (B) tends to be high and the solution viscosity (A) of the acetone solution tends to be low, the viscosity ratio (A) / (B) is likely to be constant or less. Thereby, it is easy to increase the elastic modulus of the core-shell type particles containing the vinylidene fluoride copolymer (a).
- the vinylidene fluoride polymer (b) may further contain a structural unit derived from a monomer copolymerizable with vinylidene fluoride or a structural unit derived from a crosslinkable monomer, if necessary.
- the monomer or crosslinkable monomer copolymerizable with vinylidene fluoride in the vinylidene fluoride polymer (b) is a monomer copolymerizable with vinylidene fluoride in the above-mentioned vinylidene fluoride copolymer (a).
- the same crosslinkable monomers can be used.
- the vinylidene fluoride polymer (b) may be cross-linked, i.e., a structural unit derived from a cross-linkable monomer. May be included.
- the content of the structural unit derived from the monomer copolymerizable with vinylidene fluoride in the vinylidene fluoride copolymer (a) constituting the core portion is small (for example, less than 50% by mass)
- the solution viscosity (A) of the acetone solution of the particles containing the vinylidene fluoride copolymer (a) is low (for example, less than 600 mPa ⁇ s)
- the turbidity of the NMP solution is hardly increased only by the core part, The solubility in the liquid may not be sufficiently low.
- the vinylidene fluoride polymer (b) constituting the shell part is preferably crosslinked.
- the content of the structural unit derived from the monomer copolymerizable with vinylidene fluoride in the vinylidene fluoride copolymer (a) constituting the core is large (for example, 50% by mass)
- the solution viscosity (A) of the particles containing the vinylidene fluoride copolymer (a) is high (for example, 600 mPa ⁇ s or more)
- the turbidity of the NMP solution can be easily increased even in the core portion alone, The solubility in the liquid tends to be sufficiently low.
- the vinylidene fluoride polymer (b) constituting the shell portion may not be crosslinked.
- the vinylidene fluoride polymer (b ) Preferably includes a structural unit derived from a monomer having a hydrogen-bonding polar functional group (preferably a carboxyl group-containing monomer) as a monomer copolymerizable with vinylidene fluoride.
- the content of vinylidene fluoride is preferably 97% by mass or less, more preferably 50 to 97% by mass, and 60 to 95%. More preferably, it is mass%.
- the mass ratio of the core part to the shell part is not particularly limited,
- the core portion / shell portion is preferably 40/60 to 99/1, more preferably 50/50 to 90/10, and still more preferably 50/50 to 70/30. If the mass ratio of the core part is high, the solubility in the electrolytic solution is likely to be sufficiently low, and if the mass ratio of the shell part is high, the elastic modulus is likely to be sufficiently increased.
- the adhesive resin composition layer obtained from such core-shell type particles can easily maintain high adhesiveness with the electrode even at high temperatures, and the process window in the heating or hot pressing step can be further widened.
- the inclined particles made of the vinylidene fluoride copolymer (a) preferably have a compositional deviation from the center of the particle to the surface layer.
- inclined particles with a small content of structural units derived from monomers copolymerizable with vinylidene fluoride on the outside of the particles can be obtained by controlling the structure of the polymer.
- gradient types with a large content of structural units derived from vinylidene fluoride on the outside of the particles Particles can be obtained by controlling the structure of the polymer.
- Such inclined particles are prepared by, for example, charging a part of vinylidene fluoride and a monomer copolymerizable with vinylidene fluoride more than a part of vinylidene fluoride at the time of polymerization. After the reduction, it can be obtained by post-adding the remainder of vinylidene fluoride and polymerizing.
- the viscosity will affect the stability during coating and winding. Is hard to be expressed, so that structural units derived from vinylidene fluoride are unevenly distributed inside the particles, and structures derived from monomers copolymerizable with vinylidene fluoride, branched structures, and crosslinked structures are unevenly distributed in the surface layer portion. Also good. Thereby, the elasticity of the central portion can be increased while lowering the solubility of the inclined particles in the electrolyte solution in the surface layer portion.
- cross-linked structure when the cross-linked structure is unevenly distributed in the surface layer part, such a tilted particle is obtained after the pressure is lowered while polymerizing a part of vinylidene fluoride and a monomer copolymerizable with vinylidene fluoride.
- the crosslinkable monomer and the remainder of the vinylidene fluoride can be obtained by adding them after polymerization while keeping the pressure constant.
- the inclined particle comprising the vinylidene fluoride copolymer (a) it is derived from the structural unit derived from the vinylidene fluoride in the vinylidene fluoride copolymer (a) and the monomer copolymerizable with the vinylidene fluoride.
- the content of the structural unit derived from vinylidene fluoride in the vinylidene fluoride copolymer (a) is preferably 50 to 99% by mass, More preferably, it is -95 mass%, and still more preferably 70-95 mass%.
- the content of the structural unit derived from the monomer copolymerizable with vinylidene fluoride in the vinylidene fluoride copolymer (a) is preferably 1 to 50% by mass, and preferably 5 to 40% by mass. More preferably, the content is 5 to 30% by mass.
- the turbidity of the prepared acetone solution is preferably 80 or less, more preferably 1 to 60, and even more preferably 2 to 55. When the turbidity is 80 or less, the solubility of the adhesive resin in the electrolytic solution tends to be low.
- the turbidity of the solution can be measured with a turbidimeter (cloudiness meter). Specifically, acetone is placed in a linear cell (size 10 ⁇ 36 ⁇ 55 mm) so that the height is 4 cm or more and less than 4.5 cm, and a turbidimeter (Nippon Denshoku Industries Co., Ltd., NDH2000) is used for measurement. After being put in the part, standard alignment is performed under the conditions of room temperature 20 ⁇ 2 ° C., humidity 50 ⁇ 5%, light source D65 ⁇ C, measurement method 3 (measurement method according to JIS K7136). Thereafter, an acetone solution in which the adhesive resin is dissolved is put in a cell, and the turbidity of the solution is measured under the same conditions.
- a turbidimeter cloudiness meter
- the solution viscosity (A) of the prepared acetone solution is preferably 350 to 20000 mPa ⁇ s. If the solution viscosity (A) is 350 mPa ⁇ s or more, the molecular weight (branch amount) of the adhesive resin is large, so the solubility of the adhesive resin in the electrolytic solution tends to be low, and if it is 20000 mPa ⁇ s or less, NMP The solubility in is not reduced too much. From these viewpoints, the solution viscosity (A) of the adhesive resin is more preferably 200 to 10000 mPa ⁇ s, and further preferably 500 to 6200 mPa ⁇ s.
- the viscosity of the solution can be measured with an E-type viscometer. Specifically, 1.1 ml of the solution is put in a measurement unit of a viscometer (RE550 viscometer manufactured by Toki Sangyo Co., Ltd.), cone rotor 1 ° 34 ′ ⁇ R24, rotation speed 10 rpm, measurement time 300 seconds, measurement temperature Measurements are taken at 25 ° C. The viscosity after 300 seconds is defined as the solution viscosity.
- a viscometer RE550 viscometer manufactured by Toki Sangyo Co., Ltd.
- cone rotor 1 ° 34 ′ ⁇ R24 cone rotor 1 ° 34 ′ ⁇ R24
- rotation speed 10 rpm measurement time 300 seconds
- measurement temperature Measurements are taken at 25 ° C.
- the viscosity after 300 seconds is defined as the solution viscosity.
- NMP solution properties (1) Preparation of NMP solution Part of or all of the powdered adhesive resin is dissolved in NMP (N-methylpyrrolidone) so that the concentration in the NMP solution is 5% by mass. Specifically, the adhesive resin is placed in a sample bottle in which NMP is weighed and dispersed at room temperature, and then the temperature of the solution is raised to 50 ° C. and stirred for about 5 hours. Part or all is dissolved to prepare an NMP solution.
- NMP N-methylpyrrolidone
- the turbidity of the NMP solution prepared above is preferably 2 to 95.
- the solubility of the adhesive resin in the electrolytic solution tends to be low.
- the turbidity is 95 or less, the melting point of the adhesive resin does not decrease too much.
- the turbidity of the NMP solution of the adhesive resin is more preferably 2 to 75, and further preferably 2.5 to 60.
- the turbidity of the NMP solution can be measured by the same method as described above. Note that the standard alignment is performed by inserting NMP into the cell.
- Solution viscosity (B) The solution viscosity (B) of the NMP solution prepared above may be in a range such that the ratio (A) / (B) of the solution viscosity (A) and (B) falls within the range described later.
- the solution viscosity (B) can be measured by the same method as described above.
- the ratio (A) / (B) of the adhesive resin solution viscosity (A) of the acetone solution and the solution viscosity (B) of the NMP solution is preferably 1 or more and 15 or less.
- the ratio (A) / (B) is 1 or more, the solution viscosity (B) of the NMP solution tends to be low, and the solution viscosity (A) of the acetone solution tends to be high, that is, the solubility in NMP tends to be low. (It is easy to increase the solubility in acetone). Therefore, it is easy to lower the solubility of the adhesive resin in the electrolytic solution.
- the ratio (A) / (B) is 15 or less, the solution viscosity (B) of the NMP solution is not too low, and the solution viscosity (A) of the acetone solution is not too high, that is, the solubility in NMP is not too low. Since the solubility in acetone is not too high, a high elastic modulus is easily obtained.
- the ratio (A) / (B) is more preferably 1 or more and 10 or less.
- the viscosity ratio (A) / (B) to a certain value or less, for example, a monomer (HFP or copolymerizable with vinylidene fluoride in the vinylidene fluoride copolymer (a) constituting the adhesive resin).
- CTFE the content and distribution of the crosslinkable monomer, the molecular weight of the vinylidene fluoride copolymer (a), the amount of branching should be below a certain level, or the content of the vinylidene fluoride copolymer (a) in the adhesive resin It is preferable to set it below a certain level.
- the average particle size of the adhesive resin particles is not particularly limited, but is preferably 10 nm to 1 ⁇ m, more preferably 50 to 500 nm, and further preferably 70 to 300 nm.
- the average particle diameter of the adhesive resin particles is regular in the dynamic light scattering method with the adhesive resin particles dispersed in a liquid medium (for example, water) after polymerization. It can be measured by chemical analysis. Specifically, using “DelsaMaxCORE” manufactured by BECKMAN COULTER, the particle diameter of the polymer particles is measured in accordance with JIS Z 8828, and the large peak among the two large and small peaks obtained by regularization analysis is averaged. The particle size.
- an adhesive resin is obtained by suspension polymerization, 3000 powdered vinylidene fluoride copolymer particles are photographed, and the particle diameter of each particle is assumed to be circular. Is the average particle diameter.
- the melting point of the adhesive resin is not particularly limited, but is preferably 90 ° C. or higher, more preferably 100 ° C. or higher, and further preferably 105 ° C. or higher.
- the melting point of the adhesive resin can be measured by the following method. That is, a mold having a length of 5 cm, a width of 5 cm, and a thickness of 150 ⁇ m is sandwiched between two aluminum foils sprayed with a release agent, and pressed at 200 ° C. to obtain a film. The melting point of the obtained film is measured using DSC (“DSC-1” manufactured by METTTLER) according to ASTM d 3418.
- the melting point of the adhesive resin can be adjusted by the monomer composition of the vinylidene fluoride copolymer (a) contained therein. In order to increase the melting point of the adhesive resin, for example, it is preferable to increase the content of structural units derived from vinylidene fluoride in the vinylidene fluoride copolymer (a).
- the inherent viscosity ( ⁇ i) of the adhesive resin obtained by the suspension polymerization method is preferably 0.50 to 5.0 dl / g, preferably 1.0 to 4.0 dl / g, from the viewpoint of coatability. More preferably, it is 1.0 to 3.5 dl / g.
- the inherent viscosity ( ⁇ i) can be obtained as a logarithmic viscosity at 30 ° C. of a solution obtained by dissolving 4 g of the adhesive resin in 1 liter of N, N-dimethylformamide (hereinafter simply referred to as “DMF”).
- Adhesive resin (resin containing vinylidene fluoride copolymer (a)) includes emulsion polymerization method and suspension polymerization method of vinylidene fluoride and a monomer copolymerizable therewith. It can be obtained through a step of polymerizing by a known polymerization method.
- Emmulsion polymerization method In the emulsion polymerization method, the above-mentioned monomers are hardly soluble in a liquid medium, each monomer, an emulsifier and, if necessary, a mixed liquid obtained by mixing a chain transfer agent, and further a polymerization that is soluble in the liquid medium is started. An agent is added to polymerize the monomer.
- the liquid medium is sufficient if each monomer is hardly soluble, and for example, water is preferable.
- Any emulsifier may be used as long as it can form micelles of each monomer in the liquid medium and can stably disperse the polymer synthesized by the emulsion polymerization method in the liquid medium. It can be used by appropriately selecting from agents.
- the emulsifier may be any surfactant conventionally used in the synthesis of vinylidene fluoride copolymers, such as perfluorinated surfactants, partially fluorinated surfactants, and non-fluorinated surfactants. can do.
- perfluoroalkylsulfonic acid and its salt perfluoroalkylcarboxylic acid and its salt, and fluorine-based surface activity having a fluorocarbon chain or a fluoropolyether chain are preferred, and perfluoroalkylcarboxylic acid and The salt is more preferred.
- chain transfer agent examples include ethyl acetate, methyl acetate, diethyl carbonate, acetone, ethanol, n-propanol, acetaldehyde, propyl aldehyde, ethyl propionate, and carbon tetrachloride.
- the polymerization initiator is a polymerization initiator that is soluble in a liquid medium, and may be, for example, a water-soluble peroxide, a water-soluble azo compound, a redox initiator, or the like.
- water-soluble peroxides include ammonium persulfate and potassium persulfate.
- water-soluble azo compounds include 2,2'-azobis-isobutyronitrile (AIBN) and 2,2'-azobis-2-methylbutyronitrile (AMBN).
- redox initiators include ascorbic acid-hydrogen peroxide.
- the polymerization initiator is preferably a water-soluble peroxide.
- the emulsion polymerization method may be a soap-free emulsion polymerization method or a mini-emulsion polymerization method.
- a reactive emulsifier which is a substance having a polymerizable double bond in the molecule and acting also as an emulsifier.
- the reactive emulsifier forms micelles in the system at the beginning of the polymerization, but as the polymerization proceeds, it is used and consumed as a monomer in the polymerization reaction. There is almost no in the state. Therefore, the reactive emulsifier is difficult to bleed out on the particle surface of the polymer obtained.
- reactive emulsifiers include polyoxyalkylene alkenyl ethers, sodium alkylallylsulfosuccinate, sodium methacryloyloxypolyoxypropylene sulfate, and alkoxy polyethylene glycol methacrylate.
- soap-free polymerization can be performed without using a reactive emulsifier.
- mini-emulsion polymerization method polymerization is performed by reducing the micelles to submicron size by applying a strong shearing force using an ultrasonic oscillator. At this time, in order to stabilize the refined micelle, a known hydrophobe is added to the mixed solution.
- the mini-emulsion polymerization method typically, the polymerization reaction occurs only inside each of the micelles, and each of the micelles becomes polymer fine particles, so the particle size and particle size distribution of the resulting polymer fine particles, etc. Easy to control.
- suspension polymerization method In the suspension polymerization method, a monomer dispersion obtained by dissolving an oil-soluble polymerization initiator in each monomer is mechanically stirred in water containing a suspending agent, a chain transfer agent, a stabilizer and a dispersing agent. By heating, the polymerization reaction is caused in the droplets of the suspended monomer while suspending and dispersing the monomer.
- a polymerization reaction occurs only inside each droplet of monomer, and each droplet of monomer becomes polymer fine particles. It is easy to control the particle size distribution.
- polymerization initiators include diisopropyl peroxydicarbonate, dinormalpropyl peroxydicarbonate, dinormalheptafluoropropyl peroxydicarbonate, diisopropyl peroxydicarbonate, isobutyryl peroxide, di (chlorofluoroacyl) peroxide. Oxide, di (perfluoroacyl) peroxide, t-butyl peroxypivalate, and the like.
- suspending agent examples include methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, partially saponified polyvinyl acetate, and an acrylic acid polymer.
- chain transfer agent the same ones as described above can be used.
- the core-shell type particle containing the vinylidene fluoride copolymer (a) can be obtained by a sequential polymerization method.
- a core-shell type particle having a core part made of a vinylidene fluoride copolymer (a) and a shell part made of a vinylidene fluoride polymer (b) can be copolymerized with, for example, vinylidene fluoride and vinylidene fluoride.
- vinylidene fluoride copolymer (a) or the vinylidene fluoride polymer (b) further contains a structural unit derived from the aforementioned crosslinkable monomer, these monomers can be further copolymerized during the polymerization in each step. That's fine.
- Polymerization in each step can be performed by a known polymerization method such as the above-described emulsion polymerization method or suspension polymerization method.
- the inclined particles comprising the vinylidene fluoride copolymer (a) can be obtained through a step of polymerizing vinylidene fluoride and a monomer copolymerizable with vinylidene fluoride.
- the polymerization can be performed by a known polymerization method such as an emulsion polymerization method or a suspension polymerization method, as described above.
- the composition and structure are biased from the center of the particle to the surface layer. Is preferably given.
- a part of vinylidene fluoride at the time of polymerization and a monomer copolymerizable with vinylidene fluoride more than a part of vinylidene fluoride are charged, and after the polymerization is started, It can be obtained by post-adding the remainder and polymerizing.
- the post-addition of vinylidene fluoride is preferably performed after the pressure has dropped after the start of polymerization. Specifically, the post-addition of vinylidene fluoride is preferably performed after the polymerization is started and after the pressure is lowered. Specifically, the post-addition of vinylidene fluoride is preferably performed when the pressure in the reactor has decreased by 2% or more with respect to the initial pressure, and more preferably by 15% or more. .
- the post-added monomers are only vinylidene fluoride and a crosslinkable monomer, and are substantially free of monomers copolymerizable with vinylidene fluoride (for example, 1 to the total of post-added monomers). % By mass or less, preferably 0% by mass).
- the blending amount of the crosslinkable monomer is preferably 0.1 to 4% by mass based on the total amount of vinylidene fluoride and monomers copolymerizable with vinylidene fluoride, and 1.2 to 3.5 More preferably, it is mass%.
- the blending amount of vinylidene fluoride is preferably 15% by mass or more and more preferably 12% by mass or more with respect to the total amount of all monomers constituting the viridinidene fluoride copolymer (a).
- a crosslinkable monomer when not using a crosslinkable monomer, it can carry out similarly to the said method 1. That is, as a method for imparting bias to the composition and structure of the particles, during polymerization, a part of vinylidene fluoride and a monomer copolymerizable with vinylidene fluoride are charged into a polymerization can, and after the polymerization is started, the pressure is increased. After the decrease, it is preferable to carry out the polymerization while performing the post-addition (including continuous addition of continuous post-addition) in a plurality of times so that the pressure becomes constant.
- the specific timing of post-addition and the mass ratio of post-added vinylidene fluoride and pre-added vinylidene fluoride can be the same as in Method 1 above.
- the amount of the chain transfer agent is reduced. Specifically, it is preferable to reduce the amount relative to the total amount of monomers copolymerizable with vinylidene fluoride and vinylidene fluoride (Method 2). By reducing the compounding amount of the chain transfer agent, the molecular weight (branch amount) of the obtained vinylidene fluoride copolymer (a) can be increased. Thereby, the obtained particles tend to increase the turbidity of the NMP solution, and easily increase the acetone solution viscosity (A).
- the amount of the chain transfer agent is preferably 0.2% by mass or less, and preferably 0.15% by mass or less based on the total amount of vinylidene fluoride and monomers copolymerizable with vinylidene fluoride. More preferably, it is more preferable to set it as 0.08 mass% or less.
- a crosslinked structure or a branched structure can be formed in the surface layer portion of the particles obtained by proceeding the polymerization particularly in an environment containing a large amount of vinylidene fluoride.
- a part of vinylidene fluoride and a monomer copolymerizable with vinylidene fluoride are copolymerized with vinylidene fluoride at the initial stage of polymerization.
- Method 3 the specific timing of post-addition and the mass ratio of post-added vinylidene fluoride and pre-added vinylidene fluoride can be the same as in Method 1 above.
- vinylidene fluoride copolymer (a) ′ is added to NMP, and the polymer concentration in the solution is 5 Dissolve so as to be part by mass (the turbidity at this time is less than 2), add lithium hydroxide (LiOH) powder thereto, and stir under heating.
- the vinylidene fluoride copolymer (a) ' can be modified (for example, dehydrofluoric acid), and the solubility in the electrolytic solution can be lowered.
- the content of LiOH in the solution is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the vinylidene fluoride copolymer (a). .
- the heating temperature and stirring time at the time of the alkali treatment may be such that the solubility of the obtained vinylidene fluoride copolymer (a) 'in the electrolytic solution can be lowered.
- the heating temperature can be 45 to 60 ° C., for example.
- the stirring time can be, for example, 30 minutes to 12 hours.
- the adhesive resin composition may further contain other components other than the adhesive resin.
- examples of other components include water-soluble polymers, inorganic fillers, organic fillers, solvents (dispersion media), and various additives.
- the water-soluble polymer can improve the adhesiveness between the adhesive resin composition layer and the separator and the adhesiveness between the adhesive resin composition layer and the electrode.
- the water-soluble polymer is preferably a polymer having adhesion to an adhesive resin, an electrode, or a separator.
- water-soluble polymer examples include cellulose compounds such as carboxymethylcellulose (CMC), methylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, hydroxyethylcellulose; ammonium salts or alkali metal salts of the above cellulose compounds, polyacrylic acid (PAA), Polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA), polyethylene oxide (PEO) are included.
- CMC carboxymethylcellulose
- PVP Polyvinyl pyrrolidone
- PVA polyvinyl alcohol
- PEO polyethylene oxide
- CMC carboxymethyl cellulose
- PVA polyvinyl alcohol
- PEO polyethylene oxide
- the content of the water-soluble polymer is preferably 0.01 to 20 parts by mass, and preferably 0.01 to 15 parts by mass when the total solid content of the adhesive resin composition is 100 parts by mass. More preferred.
- the inorganic filler can prevent the occurrence of a short circuit and improve the safety of the battery even when the obtained battery is exposed to a high temperature at which the separator or adhesive resin melts.
- inorganic fillers examples include silicon dioxide (SiO 2 ), alumina (Al 2 O 3 ), titanium dioxide (TiO 2 ), calcium oxide (CaO), strontium oxide (SrO), barium oxide (BaO), Oxides such as magnesium oxide (MgO), zinc oxide (ZnO), barium titanate (BaTiO 3 ); magnesium hydroxide (Mg (OH) 2 ), calcium hydroxide (Ca (OH) 2 ), zinc hydroxide ( Examples thereof include hydroxides such as Zn (OH) 2 ) aluminum hydroxide (Al (OH) 3 ); carbonates such as calcium carbonate (CaCO 3 ); sulfates such as barium sulfate; nitrides and clay minerals.
- An inorganic filler may be used individually by 1 type, and may use 2 or more types together. Among these, alumina, silicon dioxide, magnesium oxide, and zinc oxide are preferable from the viewpoint of battery safety and coating solution stability.
- the content of the inorganic filler is preferably 0.01 to 99 parts by mass, more preferably 50 to 95 parts by mass, when the total solid content of the adhesive resin composition is 100 parts by mass.
- the average particle size of the inorganic filler is preferably 5 nm to 2 ⁇ m, and more preferably 10 nm to 1 ⁇ m.
- the average particle diameter can be measured by the same method as described above.
- Examples of the inorganic filler include AKP3000 (manufactured by Sumitomo Chemical), which is commercially available as high-purity alumina particles.
- solvents examples include water and NMP.
- the content of the solvent is not particularly limited as long as the applicability is good, but is preferably 30 to 99 parts by mass when the total mass of the adhesive resin composition is 100 parts by mass, More preferred is 35 to 98 parts by mass.
- the separator structure of this invention has a separator and the adhesive resin composition layer provided in the at least one surface.
- the material of the separator is not particularly limited.
- examples thereof include polyolefin resins such as polyethylene and polypropylene; polyester resins such as polyethylene terephthalate; aromatic polyamide resins; polyimide resins such as polyetherimide; polyethersulfone and polysulfone.
- a polyolefin resin for example, polyethylene, polypropylene
- porous film is preferable from the viewpoint of excellent shutdown function and meltdown function.
- polyolefin resin porous film examples include a single-layer polypropylene separator, a single-layer polyethylene separator, and a polypropylene / polyethylene / polypropylene three-layer separator, which are commercially available as Celgard (registered trademark, manufactured by Polypore Corporation).
- Adhesive resin composition layer The adhesive resin composition layer is provided on at least one surface of the separator.
- the adhesive resin composition layer is a layer obtained using at least the above-mentioned adhesive resin composition, and may further contain other components as necessary.
- the thickness of the adhesive resin composition layer is not particularly limited as long as the adhesiveness between the separator and the electrode can be maintained satisfactorily.
- the thickness is preferably 0.5 to 25 ⁇ m, and preferably 1 to 20 ⁇ m. It is more preferable that
- the adhesive resin composition layer can be formed through a step of applying the above-mentioned adhesive resin composition on the separator and then drying, and a step of making it porous as necessary.
- the coating method is not particularly limited, and may be a method of coating with a bar coater, a die coater, and a comma coater.
- Drying is preferably performed to such an extent that the solvent in the coating film can be sufficiently removed.
- the drying temperature is preferably 40 to 180 ° C, more preferably 50 to 150 ° C.
- the drying time can be 1 minute to 15 hours.
- heat treatment may be further performed as necessary.
- the adhesive resin composition layer does not contain a water-soluble polymer as another component, it is preferable to perform heat treatment.
- the heat treatment temperature is preferably 40 to 180 ° C., more preferably 50 to 170 ° C.
- the heat treatment time can be, for example, 1 minute to 5 hours.
- Electrode structure An electrode structure has an electrode and the adhesive resin composition layer provided in the surface.
- the electrode has a current collector and an electrode active material layer provided on the surface thereof.
- the electrode may be a positive electrode or a negative electrode.
- Examples of the current collector for the negative electrode include copper.
- the copper may be metallic copper, or may be a copper foil applied to the surface of another medium.
- Examples of current collectors for positive electrodes include aluminum.
- Aluminum may be obtained by applying an aluminum foil to the surface of another medium, or may be obtained by adding net-like aluminum.
- the thickness of the current collector for the negative electrode or the positive electrode is preferably 5 to 100 ⁇ m, and more preferably 5 to 20 ⁇ m.
- the electrode active material layer includes an electrode active material and a binder, and may further include a conductive aid as necessary.
- Examples of the electrode active material for the positive electrode include a lithium-based positive electrode active material.
- Examples of the lithium-based positive electrode active material include general formula LiMY 2 (M is Co, Ni, Fe, Mn, Cr, and V) such as LiCoO 2 and LiNi x Co 1-x O 2 (0 ⁇ x ⁇ 1). 1 or 2 or more of transition metals such as, Y is a chalcogen element such as O and S), a composite metal oxide having a spinel structure such as LiMn 2 O 4 , and LiFePO 4 And olivine type lithium compounds.
- the positive electrode active material may be a commercially available product.
- the specific surface area of the active material for the positive electrode is preferably 0.05 to 50 m 2 / g, preferably 0.1 to 30 m. 2 / g is more preferable.
- Examples of the active material for the negative electrode include carbon materials, metal materials, alloy materials, metal oxides, and the like conventionally used as the active material for the negative electrode. Among these, from the viewpoint of easily obtaining stable battery characteristics, a carbon material is preferable, and artificial graphite, natural graphite, non-graphitizable carbon, graphitizable carbon, and the like are more preferable.
- Examples of the artificial graphite include artificial graphite obtained by carbonizing an organic material, further performing a heat treatment at a high temperature, pulverizing and classifying.
- Examples of non-graphitizable carbon include non-graphitizable carbon obtained by firing a material derived from petroleum pitch at 1000 to 1500 ° C.
- the negative electrode active material may be a commercially available product.
- the specific surface area of the active material for the negative electrode is preferably 0.3 to 10 m 2 / g, preferably 0.6 to 6 m. 2 / g is more preferable.
- the binder can enhance the binding property between the electrode active materials, the electrode active material and the conductive additive, or the electrode active material and the current collector.
- the binder is not particularly limited, and those widely used in lithium ion secondary batteries can be used.
- the binder include polytetrafluoroethylene, polyvinylidene fluoride (including vinylidene fluoride (co) polymers such as vinylidene fluoride-maleic acid monomethyl ester copolymer), fluorine-containing resins such as fluorine rubber, Styrene butadiene rubber latex (SBR), cellulose compounds (such as carboxymethyl cellulose), and polyacrylonitrile (PAN).
- binder for the positive electrode examples include vinylidene fluoride (co) polymer
- binder for the negative electrode examples include styrene butadiene rubber latex (SBR) and carboxymethyl cellulose (CMC). Is included.
- the content of the binder is preferably 0.2 to 15 parts by mass, and preferably 0.5 to 10 parts by mass when the total amount of the electrode active material and the binder is 100 parts by mass. More preferred.
- the conductive additive can further increase the conductivity between the electrode active materials or between the electrode active material and the current collector.
- the conductive assistant include acetylene black, ketjen black, carbon nanofiber, carbon nanotube, and carbon fiber.
- the content of the conductive auxiliary agent is preferably 0.5 to 15 parts by mass, and preferably 0.5 to 5 parts by mass, when the total amount of the electrode active material and the binder is 100 parts by mass. More preferred.
- the electrode active material layer can be formed by applying a mixture on a current collector and drying it.
- the mixture is a mixture of the above-described electrode active material, binder, and optionally a conductive additive and a non-aqueous solvent so as to form a uniform slurry.
- non-aqueous solvents include acetone, dimethyl sulfoxide, ethyl methyl ketone, diisopropyl ketone, cyclohexanone, methylcyclohexane, ethyl acetate, ⁇ -butyrolactone, tetrahydrofuran, acetamide, N-methylpyrrolidone, N, N-dimethylformamide, propylene carbonate Dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate and the like.
- Application method is not particularly limited, and a method of applying with a bar coater, a die coater, and a comma coater can be employed. Drying after coating is usually performed at 50 to 150 ° C. for 1 to 300 minutes. Drying may be performed multiple times at different temperatures. In drying, pressure may be applied, but usually drying is performed under atmospheric pressure or reduced pressure. You may heat-process after drying. The heat treatment is usually performed at 100 to 300 ° C. for 10 seconds to 300 minutes.
- further press treatment may be performed.
- the press treatment is usually performed at 1 to 200 MPa. By performing the pressing process, the electrode density can be improved.
- the thickness of the electrode active material layer for the positive electrode is preferably 40 to 500 ⁇ m, and more preferably 100 to 400 ⁇ m.
- the thickness of the electrode active material layer for the negative electrode is preferably 20 to 400 ⁇ m, and more preferably 40 to 300 ⁇ m.
- the basis weight of the electrode active material layer is preferably 20 to 700 g / m 2 , and more preferably 30 to 500 g / m 2 .
- Adhesive resin composition layer is a layer obtained using the above-mentioned adhesive resin composition, and is provided on the electrode.
- the configuration and forming method of the adhesive resin composition layer are the same as the above-described configuration and forming method of the adhesive resin composition layer.
- Nonaqueous electrolyte secondary battery includes a positive electrode, a negative electrode, a separator disposed therebetween, at least one between the separator and the positive electrode, and between the separator and the negative electrode. And an adhesive resin composition layer provided.
- the adhesive resin composition layer is a layer obtained from the aforementioned adhesive resin composition layer, and is provided between at least one of the separator and the positive electrode and between the separator and the negative electrode. Especially, it is preferable that the adhesive resin composition layer is provided between the separator and the negative electrode.
- Such a non-aqueous electrolyte secondary battery includes the positive electrode, the negative electrode, the separator disposed between them, the separator and the negative electrode, and the separator and the positive electrode. It can be manufactured through a step of obtaining a laminate having an adhesive resin composition layer and a step of heating or hot pressing the obtained laminate.
- the above-mentioned laminate can be manufactured by any method.
- the laminate may be obtained by laminating the positive electrode, the negative electrode, and the separator structure described above; the negative electrode structure having the adhesive resin composition layer (or the positive electrode structure having the adhesive resin composition layer) ), A positive electrode (or negative electrode), and a separator may be laminated to obtain a laminate.
- the heating or hot pressing of the obtained laminate may be performed before or after the step of impregnating the laminate with the electrolytic solution. From the viewpoint of accelerating the impregnation of the electrolytic solution into the adhesive resin composition layer and reducing the increase in internal resistance due to the adhesive resin composition layer when the battery is made, from the viewpoint of reducing the temperature during heating or hot pressing, Heating or hot pressing is preferably performed after the obtained laminate is impregnated with an electrolytic solution.
- the non-aqueous electrolyte secondary battery of the present invention when the non-aqueous electrolyte secondary battery of the present invention is exemplified by a laminate cell, 1) the step of obtaining the above-mentioned laminate, 2) the obtained laminate is put in a (bag-like) laminate cell, and electrolysis is performed. A step of sealing the laminate cell after impregnating the liquid, and 3) a step of heating or hot pressing the sealed laminate cell to bond the electrode and the separator through the adhesive resin composition layer. It can be obtained through.
- the heating or hot pressing temperature is not particularly limited as long as it can adhere the separator and the electrode, but is preferably 40 to 180 ° C, and more preferably 60 to 110 ° C.
- the adhesive resin composition layer obtained by using the adhesive resin composition of the present invention is easy to obtain adhesiveness between the separator and the electrode in a wide temperature range (for example, 20 to 50 ° C.). Has a wide process window.
- the heating or hot pressing time is, for example, 20 seconds to 30 minutes.
- the pressure of the hot press is, for example, 1 to 30 MPa.
- the adhesive resin composition layer is exposed to a high temperature environment in the presence of the electrolytic solution. Even under such a high temperature, the adhesive resin composition layer obtained using the adhesive resin composition of the present invention hardly dissolves in the electrolyte solution even at a certain temperature or higher, and has a high elastic modulus. Have. Thereby, not only the high adhesiveness between the separator and the electrode can be maintained, but also the heating or hot pressing temperature range (process window) can be widened, so that the battery defect rate can be reduced.
- the negative electrode often contains a resin other than the vinylidene fluoride polymer, as compared with the positive electrode often contains a vinylidene fluoride polymer as a binder, and an adhesive resin composition containing a vinylidene fluoride polymer. It is difficult to bond well with the separator through the layer. Even in such a case, the adhesive resin composition layer obtained by using the adhesive resin composition of the present invention can maintain high adhesion between the separator and the negative electrode at high temperature and widen the process window. it can.
- Preparation of adhesive resin particles and measurement of physical properties ⁇ Preparation of polymer particles 1 (core-shell type particles)> (1) Polymerization of core part 333 parts by mass of ion-exchanged water and 0.53 part by mass of sodium pyrophosphate as a neutral buffer were placed in an autoclave, and deaerated by nitrogen bubbling for 30 minutes. Next, 1.3 parts by mass of ammonium perfluorooctanoate (PFOA) was charged and pressurized to 4.5 MPa to perform nitrogen substitution three times. 0.125 parts by mass of ethyl acetate, 20 parts by mass of vinylidene fluoride (VDF), and 30 parts by mass of chlorotrifluoroethylene (CTFE) were placed in a monomer charge pot.
- PFOA ammonium perfluorooctanoate
- PFOA perfluorooctanoic acid ammonium salt
- shell part 700 parts by mass of ion-exchanged water and 0.5 part by mass of disodium hydrogen phosphate were put in an autoclave, and deaeration was performed by nitrogen bubbling for 30 minutes.
- 100 parts by mass of water-dispersed core part particles and 0.5 part by mass of PFOA were charged and pressurized to 4.5 MPa to perform nitrogen substitution three times.
- 0.05 parts by mass of ethyl acetate and 100 parts by mass of vinylidene fluoride (VDF) were added all at once to the autoclave. After raising the temperature to 80 ° C.
- a 5 wt% APS aqueous solution was added in an amount corresponding to 0.1 part by mass in terms of APS to initiate polymerization.
- the pressure inside the can at this time was 4.1 MPa.
- the polymerization of the shell part was completed, and the shell part made of the vinylidene fluoride polymer (b-1) was formed, whereby core-shell type polymer particles 2 were obtained.
- the average particle diameter of the obtained particles was 199 nm.
- PFOA perfluorooctanoic acid ammonium salt
- ⁇ Preparation of polymer particles 4 (core-shell type particles)> (1) Polymerization of core part 333 parts by mass of ion-exchanged water and 0.53 part by mass of sodium pyrophosphate as a neutral buffer were placed in an autoclave, and deaerated by nitrogen bubbling for 30 minutes. Next, 1.33 parts by mass of perfluorooctanoic acid ammonium salt (PFOA) was charged and pressurized to 4.5 MPa to perform nitrogen substitution three times. 0.25 parts by mass of ethyl acetate, 15 parts by mass of vinylidene fluoride (VDF), and 35 parts by mass of chlorotrifluoroethylene (CTFE) were placed in a monomer charge pot.
- PFOA perfluorooctanoic acid ammonium salt
- a-6 vinylidene fluoride copolymer (vinylidene fluoride / hexafluoro Polymer particles 6 made of a propylene copolymer) were obtained.
- the average particle diameter of the obtained particles was 170 ⁇ m.
- a vinylidene fluoride copolymer (c-1) (vinylidene fluoride / hexafluoro Polymer particles 8 made of a propylene copolymer) were obtained.
- the average particle diameter of the obtained particles was 173 ⁇ m.
- a vinylidene fluoride copolymer (c-3) (vinylidene fluoride / hexafluoro Polymer particles 10 made of a propylene copolymer) were obtained.
- the average particle diameter of the obtained particles was 165 ⁇ m.
- a 5% by mass ammonium persulfate (APS) aqueous solution was added in an amount corresponding to 0.06 parts by mass in terms of APS to initiate polymerization.
- the internal pressure of the can was 3.83 MPa.
- VDF vinylidene fluoride
- the polymerization was terminated to obtain polymer particles 12 made of vinylidene fluoride copolymer (c-5). The average particle diameter of the obtained particles was 187 nm.
- ethyl acetate 80 parts by mass of vinylidene fluoride (VDF), 20 parts by mass of chlorotrifluoroethylene (CTFE), and 1 part by mass of perfluorodivinyl ether (PFDVE) were placed in a monomer charge pot.
- VDF vinylidene fluoride
- CFE chlorotrifluoroethylene
- PFDVE perfluorodivinyl ether
- PFOA perfluorooctanoic acid ammonium salt
- VDF vinylidene fluoride
- CFE chlorotrifluoroethylene
- PFDVE perfluorodivinyl ether
- the remaining monomer was purged to form a shell portion made of the vinylidene fluoride polymer (b-2), whereby core-shell polymer particles 14 were obtained.
- the average particle diameter of the obtained particles was 133 nm.
- APS ammonium persulfate
- aqueous solution was added in an amount corresponding to 0.1 part by mass in terms of APS to initiate polymerization.
- the internal pressure of the can at this time was 3.5 MPa.
- PFDVE perfluorodivinyl ether
- 63.3 parts by mass of vinylidene fluoride was maintained at 2.5 MPa in the can. Added continuously.
- the pressure was reduced to 1.5 MPa, the polymerization was terminated, and polymer particles 15 made of vinylidene fluoride copolymer (c-7) were obtained.
- the average particle diameter of the obtained particles was 98 nm.
- ⁇ Preparation of polymer particles 16 (core-shell type particles)> (1) Polymerization of core part 330 parts by mass of ion-exchanged water was put into an autoclave, and deaeration was performed by nitrogen bubbling for 30 minutes. Next, 1.0 mass part of perfluorooctanoic acid ammonium salt (PFOA) was prepared, and it pressurized to 4.5 Mpa, and performed nitrogen substitution 3 times. 0.05 parts by mass of ethyl acetate, 10 parts by mass of vinylidene fluoride (VDF), and 30 parts by mass of hexafluoropropylene (HFP) were collectively added to the autoclave.
- PFOA perfluorooctanoic acid ammonium salt
- shell part 700 parts by mass of ion-exchanged water and 0.5 part by mass of disodium hydrogen phosphate were put in an autoclave, and deaeration was performed by nitrogen bubbling for 30 minutes.
- 100 parts by mass of water-dispersed core part particles and 0.5 part by mass of PFOA were charged and pressurized to 4.5 MPa to perform nitrogen substitution three times.
- 0.05 parts by mass of ethyl acetate and 100 parts by mass of vinylidene fluoride (VDF) were added all at once to the autoclave. After raising the temperature to 80 ° C.
- a 5 wt% APS aqueous solution was added in an amount corresponding to 0.1 part by mass in terms of APS to initiate polymerization.
- the internal pressure of the can was 4.0 MPa.
- the polymerization of the shell part was completed, and the shell part made of the vinylidene fluoride copolymer (b-1) was formed to obtain core-shell polymer particles 16. .
- the average particle diameter of the obtained particles was 203 nm.
- the resulting polymer particles 1 to 19 have a melting point, a solution viscosity when dissolved in acetone (A), a turbidity when dissolved in NMP, a solution viscosity when dissolved in NMP (B), inherent Viscosity and average particle diameter were measured by the following methods, respectively.
- the melting point of the polymer particles obtained was measured in the form of a film.
- the film was produced by the following method. That is, a mold having a length of 5 cm, a width of 5 cm, and a thickness of 150 ⁇ m was sandwiched between two aluminum foils sprayed with a release agent and pressed at 200 ° C. Using the obtained film, the melting point of the vinylidene fluoride copolymer was measured according to ASTM d 3418 using DSC (“DSC-1” manufactured by METTTLER).
- the viscosity of the obtained acetone solution was measured with an E-type viscometer. Specifically, 1.1 ml of an acetone solution is put into a measurement unit of a viscometer (RE550 viscometer manufactured by Toki Sangyo Co., Ltd.), cone rotor 1 ° 34 ′ ⁇ R24, rotation speed 10 rpm, measurement time 300 seconds, measurement The measurement was performed at a temperature of 25 ° C. The viscosity at the time when 300 seconds had elapsed was defined as the acetone solution viscosity.
- a viscometer RE550 viscometer manufactured by Toki Sangyo Co., Ltd.
- the turbidity of the obtained NMP solution was measured with a turbidimeter (cloudiness meter). Specifically, NMP is put in a rectangular cell (size 10 ⁇ 36 ⁇ 55 mm) so that the height is 4 cm or more and less than 4.5 cm, and is added to the measurement part of a turbidimeter (NDH2000, Nippon Denshoku Industries Co., Ltd.). After being put in, standard alignment is performed under the conditions of room temperature 20 ⁇ 2 ° C., humidity 50 ⁇ 5%, light source D65 ⁇ C, measurement method 3 (measurement method according to JIS K7136 (how to determine haze of plastic-transparent material)). went. Thereafter, the NMP solution in which the adhesive resin was dissolved was put into the cell, and the turbidity of the solution was measured under the same conditions.
- ⁇ i (1 / C) ⁇ ln ( ⁇ / ⁇ 0) ⁇ is the measured viscosity of the solution, ⁇ 0 is the measured viscosity of DMF, and C is the concentration of particles containing the vinylidene fluoride copolymer in the solution, here 0.4 (g / dl) is there.
- the average particle diameter was calculated by regularization analysis of the dynamic light scattering method. Specifically, using “DelsaMaxCORE” manufactured by BECKMAN COULTER, the particle diameter of polymer particles is measured in accordance with JIS Z 8828, and a large peak is averaged out of two large and small peaks obtained by regularization analysis. The particle diameter was taken. On the other hand, when polymer particles were obtained by suspension polymerization, 3000 powdered polymer particles were photographed, and the average value of the particle diameters when assuming that each photographed particle was circular was calculated. The average particle size was taken.
- the constitution of the obtained polymer particles 1 to 19 is shown in Table 1, and the measurement results of physical properties are shown in Table 2.
- Table 2 “-” indicates that measurement is not possible.
- Adhesive Resin Composition [Examples 1 to 10, Comparative Examples 1 to 9]
- the polymer particles (adhesive resin particles) shown in Tables 1 and 2 were dispersed in NMP so that the polymer concentration in the solution was 5% by mass to obtain an adhesive resin composition.
- An adhesive resin composition was prepared by separating a separator (single layer separator made of polyethylene, thickness 20 ⁇ m, porosity 40%, air permeability 300 sec, tensile strength (MD) 150 MPa, (TD) 130 MPa, tensile elongation (MD) 50%, (TD) 100%) on one side using a wire bar with a wet coating amount of 24 ⁇ m (count 12) and then immersed in a coagulation bath (water) at 23 ⁇ 2 ° C for 3 minutes did. Then, it was immersed in a cleaning liquid (water) for 1 minute and dried under nitrogen at 70 ° C. for 30 minutes. Furthermore, it heat-processed in vacuum at 60 degreeC for 3 hours, and obtained the separator structure which has the adhesive resin composition layer of thickness 2 micrometers.
- a separator single layer separator made of polyethylene, thickness 20 ⁇ m, porosity 40%, air permeability 300 sec, tensile strength (MD) 150 MPa, (TD) 130 MPa, ten
- Negative Electrode 95 parts by mass of BTR918 (made of modified natural graphite BTR) as a negative electrode active material, 2 parts by mass of a conductive additive (manufactured by SuperP TIMCAL), and SBR (styrene butadiene rubber) latex (BM-400) as a binder
- a slurry was prepared by adding water to 2 parts by mass of Nippon Zeon) and 1 part by mass of CMC (carboxymethylcellulose) (Serogen 4H, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) as a thickener, and applied to a copper foil (thickness 10 ⁇ m).
- the applied slurry was dried and then pressed and heat-treated at 150 ° C. for 3 hours.
- a negative electrode active material layer having an electrode bulk density of 1.6 g / cm 3 and a basis weight of 60 g / m 2 was formed to obtain a negative electrode.
- peel strength measurement sample a laminate of the electrode and the separator was taken out.
- the negative electrode of the obtained laminate was fixed, and a tensile tester (“STA-1150 UNIVERSAL TESTING MACHINE” manufactured by ORIENTEC) was used, and a 180 ° peel test was performed at a head speed of 200 mm / min to measure peel strength. .
- the same measurement was repeated while changing the hot press temperature in the range of 50 to 110 ° C.
- three samples were prepared for each hot press temperature, the peel strength was measured, and the average value thereof was defined as “peel strength at each hot press temperature”.
- the maximum value of “peel strength at each hot press temperature” when the same measurement was repeated while changing the hot press temperature in the range of 50 to 110 ° C. was defined as “peel strength”.
- Table 3 shows the evaluation results of the peel strength and the adhesive temperature range of the adhesive resin compositions of Examples 1 to 10 and Comparative Examples 1 to 9.
- the peel strength between the separator and the negative electrode is high, and the adhesive temperature range is as wide as 20 ° C. or more.
- the adhesive resin containing the adhesive resin particle which can maintain the high adhesiveness of a separator and an electrode and has a wide process window in a heating or a hot press process A composition can be provided.
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Battery Electrode And Active Subsutance (AREA)
- Secondary Cells (AREA)
- Cell Separators (AREA)
- Adhesive Tapes (AREA)
- Adhesives Or Adhesive Processes (AREA)
Abstract
Description
電解液に対する溶解性が低い重合体は、通常、NMPに対する溶解性は低く、アセトンに対する溶解性は高い傾向を示す。NMPに対する溶解性が低いと、NMPに溶解させたときの濁度は高くなりやすい。アセトンに対する溶解性が高いと、アセトンに溶解させたときの溶液粘度(A)は高くなりやすい。
本発明者らは、鋭意検討した結果、フッ化ビニリデン共重合体(a)を含む接着性樹脂を、NMPに溶解させたときの濁度が2以上95以下であると、電解液に対する溶解性が適度に低くなりやすく、かつアセトンに溶解させたときに溶液粘度(A)が350~20000mPa・sであると、当該接着性樹脂の電解液に対する親和性を部分的に制御することができ、当該接着性樹脂の電解液に対する溶解性を低くしうることを見出した(i)の要件)。
これとは逆に、高い弾性率を有する重合体は、通常、NMPに対する溶解性は高く、アセトンに対する溶解性は低い傾向を示す。NMPに対する溶解性が高いと、NMPに溶解させたときの溶液粘度(B)は高くなりやすい。アセトンに対する溶解性が低いと、アセトンに溶解させたときの溶液粘度(A)は低くなりやすい。
本発明者らは、鋭意検討した結果、フッ化ビニリデン共重合体(a)を含む接着性樹脂の、アセトン溶液の溶液粘度(A)とNMP溶液の溶液粘度(B)の比(A)/(B)を1以上15以下とすることで、高い弾性率と、電解液に対する低い溶解性とをバランス良く両立しうることを見出した(ii)の要件)。
i)接着性樹脂をNMPに溶解させたときの濁度が2以上95以下であり、かつ接着性樹脂をアセトンに溶解させたときの溶液粘度(A)が350~20000mPa・sであること
ii)接着性樹脂をNMPに溶解させたときの溶液粘度(B)に対する溶液粘度(A)の比(A)/(B)が1以上15以下であること
本発明の接着性組成物は、少なくとも接着性樹脂を含む。
接着性樹脂は、少なくともフッ化ビニリデン共重合体(a)を含む。
フッ化ビニリデン共重合体(a)は、フッ化ビニリデンに由来する構成単位と、フッ化ビニリデンと共重合可能な単量体に由来する構成単位とを含む。
フッ化ビニリデン共重合体(a)を含むコアシェル型粒子は、フッ化ビニリデン共重合体(a)からなるコア部と、それとは異なるフッ化ビニリデン重合体(b)からなるシェル部とを有していてもよいし;フッ化ビニリデン重合体(b)からなるコア部と、フッ化ビニリデン共重合体(a)からなるシェル部とを有していてもよい。中でも、フッ化ビニリデンと共重合可能な単量体に由来する構造単位の含有量が多いと、粘性が増す傾向があることから、フッ化ビニリデンと共重合可能な単量体に由来する構造単位の含有量が少ないフッ化ビニリデン重合体(b)がシェル部を構成することが、塗工時および捲回時の安定性を良好にする観点から好ましい。すなわち、フッ化ビニリデン共重合体(a)からなるコア部と、それとは異なるフッ化ビニリデン重合体(b)からなるシェル部とを有するコアシェル型粒子が好ましい。
フッ化ビニリデン共重合体(a)からなる傾斜型粒子は、粒子の中心部から表層部にわたって、組成の偏りを有していることが好ましい。
(アセトン溶液物性)
(1)アセトン溶液の作製
粉体化した接着性樹脂を、アセトン溶液中の濃度が10質量%になるようにアセトンに溶解させる。具体的には、アセトンを量り取ったサンプル瓶の中で、接着性樹脂を常温にて分散させた後、45℃に設定したウォーターバスに入れて約2時間撹拌し、接着性樹脂の一部または全部が溶解した、アセトン溶液を調製する。アセトン溶液の濁度および溶液粘度は、調製したアセトン溶液を室温に放冷した後、直ちに測定されることが好ましい。
上記調製したアセトン溶液の濁度は、80以下であることが好ましく、1~60であることがより好ましく、2~55であることがさらに好ましい。濁度が80以下であると、接着性樹脂の電解液に対する溶解性が低くなりやすい。
上記調製したアセトン溶液の溶液粘度(A)は、350~20000mPa・sであることが好ましい。溶液粘度(A)が350mPa・s以上であると、接着性樹脂の分子量(分岐量)が多いため、接着性樹脂の電解液に対する溶解性が低くなりやすく、20000mPa・s以下であると、NMPに対する溶解性が低下し過ぎない。接着性樹脂の溶液粘度(A)は、これらの観点から、200~10000mPa・sであることがより好ましく、500~6200mPa・sであることがさらに好ましい。
(1)NMP溶液の調製
粉体化した接着性樹脂を、NMP溶液中の濃度が5質量%になるように、NMP(N-メチルピロリドン)に加え、一部または全部を溶解させる。具体的には、NMPを計量したサンプル瓶に、接着性樹脂を入れ、室温で分散させた後、溶液温度が50℃になるように昇温し、約5時間撹拌して接着性樹脂の一部または全部を溶解させて、NMP溶液を調製する。
上記調製したNMP溶液の濁度は、2~95であることが好ましい。濁度が2以上であると、接着性樹脂の電解液に対する溶解性が低くなりやすい。濁度が95以下であると、接着性樹脂の融点が下がりすぎない。接着性樹脂のNMP溶液の濁度は、上記観点から、2~75であることがより好ましく、2.5~60であることがさらに好ましい。NMP溶液の濁度は、前述と同様の方法で測定することができる。なお、標準合わせは、セルにNMPを入れて行う。
上記調製したNMP溶液の溶液粘度(B)は、溶液粘度(A)と(B)の比(A)/(B)が後述する範囲となるような範囲であればよい。溶液粘度(B)は、前述と同様の方法で測定することができる。
接着性樹脂の、アセトン溶液の溶液粘度(A)とNMP溶液の溶液粘度(B)の比(A)/(B)は、1以上15以下であることが好ましい。比(A)/(B)が1以上であると、NMP溶液の溶液粘度(B)は低くなりやすく、アセトン溶液の溶液粘度(A)は高くなりやすい、すなわちNMPに対する溶解性を低くしやすい(アセトンに対する溶解性を高くしやすい)。そのため、接着性樹脂の電解液に対する溶解性を低くしやすい。比(A)/(B)が15以下であると、NMP溶液の溶液粘度(B)は低すぎず、アセトン溶液の溶液粘度(A)は高すぎない、すなわちNMPに対する溶解性が低すぎない(アセトンに対する溶解性が高すぎない)ため、高い弾性率が得られやすい。比(A)/(B)は、1以上10以下であることがさらに好ましい。
接着性樹脂粒子の平均粒子径は、特に制限されないが、10nm~1μmであることが好ましく、50~500nmであることがより好ましく、70~300nmであることがさらに好ましい。
接着性樹脂の融点は、特に制限されないが、90℃以上であることが好ましく、100℃以上であることがより好ましく、105℃以上であることがさらに好ましい。
懸濁重合法で得られる接着性樹脂のインヘレント粘度(ηi)は、塗工性の観点から、0.50~5.0dl/gであることが好ましく、1.0~4.0dl/gであることがより好ましく、1.0~3.5dl/gであることがさらに好ましい。
接着性樹脂(フッ化ビニリデン共重合体(a)を含む樹脂)は、フッ化ビニリデンとそれと共重合可能な単量体とを、乳化重合法および懸濁重合法を含む公知の重合方法で重合させる工程を経て得ることができる。
乳化重合法では、前述の各モノマーが難溶の液性媒体、各モノマー、乳化剤、および必要に応じて連鎖移動剤を混合して得られる混合液に、さらに液性媒体に溶解性の重合開始剤を加えて、モノマーを重合させる。
懸濁重合法は、油溶性の重合開始剤を各モノマーに溶解させて得られるモノマー分散液を、懸濁剤、連鎖移動剤、安定剤および分散剤などを含む水中で機械的に攪拌しつつ加温することにより、モノマーを懸濁および分散させつつ、懸濁したモノマーによる液滴の中で重合反応を生じさせる。懸濁重合法では、典型的には、モノマーによる液滴のそれぞれの内部でのみ重合反応が生じ、モノマーによる液滴のそれぞれが重合体の微粒子となるため、得られる重合体の微粒子の粒径および粒径分布などを制御しやすい。
フッ化ビニリデン共重合体(a)を含むコアシェル型粒子は、逐次重合法により得ることができる。例えば、フッ化ビニリデン共重合体(a)からなるコア部と、フッ化ビニリデン重合体(b)からなるシェル部とを有するコアシェル型粒子は、例えばフッ化ビニリデンと、フッ化ビニリデンと共重合可能な単量体とを共重合させて、フッ化ビニリデン共重合体(a)からなるコア部を形成する工程、および得られたコア部の周囲に、少なくともフッ化ビニリデンを重合させて、フッ化ビニリデン共重合体(b)からなるシェル部を形成する工程、を経て製造することができる。
フッ化ビニリデン共重合体(a)からなる傾斜型粒子は、フッ化ビニリデンと、フッ化ビニリデンと共重合可能な単量体とを重合させる工程を経て得ることができる。重合は、前述と同様に、乳化重合法または懸濁重合法などの公知の重合方法で行うことができる。
接着性樹脂組成物は、接着性樹脂以外の他の成分をさらに含んでいてもよい。他の成分の例には、水溶性高分子や無機フィラー、有機フィラー、溶媒(分散媒)および各種添加剤が含まれる。
本発明のセパレータ構造体は、セパレータと、その少なくとも一方の表面に設けられた接着性樹脂組成物層とを有する。
セパレータの材質は、特に限定されないが、その例には、ポリエチレン、ポリプロピレンなどのポリオレフィン樹脂;ポリエチレンテレフタレートなどのポリエステル樹脂;芳香族ポリアミド樹脂;ポリエーテルイミドなどのポリイミド系樹脂;ポリエーテルスルホン、ポリスルホン、ポリエーテルケトン、ポリスチレン、ポリエチレンオキサイド、ポリカーボネート、ポリ塩化ビニル、ポリアクリロニトリル、ポリメチルメタクリレート、セラミックス等、およびこれらの混合物からなる単層または多層の多孔膜が含まれる。中でも、シャットダウン機能やメルトダウン機能に優れる観点などから、ポリオレフィン樹脂(例えば、ポリエチレン、ポリプロピレン)の多孔膜が好ましい。
接着性樹脂組成物層は、セパレータの少なくとも一方の表面に設けられている。接着性樹脂組成物層は、少なくとも前述の接着性樹脂組成物を用いて得られる層であり、必要に応じて他の成分をさらに含んでもよい。
電極構造体は、電極と、その表面に設けられた接着性樹脂組成物層とを有する。
電極は、集電体と、その表面に設けられた電極活物質層とを有する。電極は、正極であってもよいし、負極であってもよい。
負極用の集電体の例には、銅が含まれる。銅は、金属銅でもよいが、他の媒体の表面に銅箔を施したものでもよい。
電極活物質層は、電極活物質と、結着剤とを含み、必要に応じて導電助剤をさらに含みうる。
接着性樹脂組成物層は、前述の接着性樹脂組成物を用いて得られる層であり、電極上に設けられている。接着性樹脂組成物層の構成および形成方法は、前述の接着性樹脂組成物層の構成および形成方法と同様である。
本発明の非水電解質二次電池は、正極と、負極と、それらの間に配置されたセパレータと、セパレータと正極との間およびセパレータと負極との間の少なくとも一方に設けられた接着性樹脂組成物層とを有する。
<重合体粒子1(コアシェル型粒子)の調製>
(1)コア部の重合
オートクレーブにイオン交換水333質量部、中性バッファとしてピロリン酸ナトリウム0.53質量部を入れ、30分間窒素バブリングによって脱気を行った。次に、パーフルオロオクタン酸アンモニウム塩(PFOA)1.3質量部を仕込み、4.5MPaまで加圧して窒素置換を3回行った。酢酸エチル0.125質量部、フッ化ビニリデン(VDF)20質量部、クロロトリフルオロエチレン(CTFE)30質量部をモノマー用チャージポットに入れた。このモノマー混合物の一部27質量部を上記オートクレーブ中に一括添加した。これを撹拌しながら、80℃に昇温後、5質量%過硫酸アンモニウム(APS)水溶液を、APS換算で0.07質量部に相当する量を入れて、重合を開始した。反応開始後、圧力が2%以上降下したところで、残りのモノマー混合物23質量部を圧力が一定になるように連続添加した。圧力が1.5MPaまで低下したところで重合を終了し、フッ化ビニリデン共重合体(a-1)からなるコア部を得た。得られたコア部の平均粒子径は、98nmであった。
予め、モノマーチャージ用ポットに、フッ化ビニリデン(VDF)50質量部、および酢酸エチル0.125質量部を計量し、モノマー混合物を準備した。上記のコア部乳化重合に続けて、80℃において、上記モノマー混合物を缶内圧力が維持されるように連続供給し、重合を行った。モノマー添加終了後、缶内圧力が2.5MPaに降圧したところで、シェル部の重合を完了し、フッ化ビニリデン重合体(b-1)からなるシェル部を形成した。得られたコアシェル型の重合体粒子1(接着性樹脂粒子)の平均粒子径は135nmであった。
(1)コア部の重合
オートクレーブに、イオン交換水330質量部を入れ、30分間の窒素バブリングによって脱気を行った。次に、パーフルオロオクタン酸アンモニウム塩(PFOA)1.0質量部を仕込み、4.5MPaまで加圧して窒素置換を3回行った。酢酸エチル0.05質量部、フッ化ビニリデン(VDF)10質量部、およびヘキサフルオロプロピレン(HFP)30質量部を、上記オートクレーブ中に一括添加した。これを撹拌しながら、80℃に昇温後、5質量%過硫酸アンモニウム(APS)水溶液を、APS換算で0.1質量部に相当する量を入れて、重合を開始した。この時の缶内圧力は2.6MPaであった。反応開始後、2.5MPaまで圧力が降下したところで、架橋性モノマーとしてパーフルオロジビニルエーテル(PFDVE)を1質量部投入し、その後、フッ化ビニリデン(VDF)60質量部を、缶内圧力が2.5MPaで維持するように連続添加した。圧力が1.5MPaまで低下したところで重合を終了し、フッ化ビニリデン共重合体(a-2)からなるコア部の粒子を得た。得られた粒子の平均粒子径は158nmであった。
オートクレーブにイオン交換水700質量部、リン酸水素二ナトリウム0.5質量部を入れ、30分間の窒素バブリングによって脱気を行った。次に、水分散したコア部の粒子100質量部、PFOA0.5質量部を仕込み、4.5MPaまで加圧して窒素置換を3回行った。酢酸エチル0.05質量部、フッ化ビニリデン(VDF)100質量部を上記オートクレーブ中に一括添加した。撹拌下で80℃に昇温後、5wt%APS水溶液をAPS換算で0.1質量部に相当する量を入れて重合を開始した。この時の缶内圧力は4.1MPaであった。反応開始後、1.5MPaまで圧力が降下したところでシェル部の重合を完了とし、フッ化ビニリデン重合体(b-1)からなるシェル部を形成し、コアシェル型の重合体粒子2を得た。得られた粒子の平均粒子径は199nmであった。
(1)コア部の重合
オートクレーブにイオン交換水333質量部、中性バッファとしてピロリン酸ナトリウム0.53質量部を入れ、30分間窒素バブリングによって脱気を行った。次に、パーフルオロオクタン酸アンモニウム塩(PFOA)1.33質量部を仕込み、4.5MPaまで加圧して窒素置換を3回行った。酢酸エチル0.25質量部、フッ化ビニリデン(VDF)29質量部、クロロトリフルオロエチレン(CTFE)21質量部、架橋性モノマーとしてパーフルオロジビニルエーテル(PFDVE)0.5質量部をモノマー用チャージポットに入れた。このモノマー混合物の一部27質量部を上記オートクレーブ中に一括添加した。これを撹拌しながら、80℃に昇温後、5質量%過硫酸アンモニウム(APS)水溶液を、APS換算で0.07質量部に相当する量を入れて、重合を開始した。反応開始後、圧力が2%以上降下したところで、残りのモノマー混合物23質量部を圧力が一定になるように連続添加した。圧力が1.5MPaまで低下したところで重合を終了し、フッ化ビニリデン重合体(a-3)からなるコア部の乳化重合を終了した。得られたコア部の粒子の平均粒子径は、97nmであった。
予め、モノマーチャージ用ポットに、フッ化ビニリデン(VDF)50質量部、および酢酸エチル0.25質量部を計量し、モノマー混合物を準備した。上記のコア部乳化重合に続けて、80℃において、上記モノマー混合物を缶内圧力が3.2MPaに維持されるように連続供給し、重合を行った。モノマー添加終了後、缶内圧力が2.5MPaに降圧したところで、シェル部の重合を完了とし、フッ化ビニリデン重合体(b-2)からなるシェル部を形成し、コアシェル型の重合体粒子3を得た。得られた粒子の平均粒子径は132nmであった。
(1)コア部の重合
オートクレーブにイオン交換水333質量部、中性バッファとしてピロリン酸ナトリウム0.53質量部を入れ、30分間窒素バブリングによって脱気を行った。次に、パーフルオロオクタン酸アンモニウム塩(PFOA)1.33質量部を仕込み、4.5MPaまで加圧して窒素置換を3回行った。酢酸エチル0.25質量部、フッ化ビニリデン(VDF)15質量部、クロロトリフルオロエチレン(CTFE)35質量部をモノマー用チャージポットに入れた。このモノマー混合物の一部27質量部を上記オートクレーブ中に一括添加した。これを撹拌しながら、80℃に昇温後、5質量%過硫酸アンモニウム(APS)水溶液を、APS換算で0.06質量部に相当する量を入れて、重合を開始した。反応開始後、圧力が2%以上降下したところで、残りのモノマー混合物23質量部を圧力が一定に維持するように連続添加した。圧力が1.5MPaまで低下したところで重合を終了し、フッ化ビニリデン共重合体(a-4)からなるコア部の粒子を得た。得られたコア部の粒子の平均粒子径は94nmであった。
予め、モノマーチャージ用ポットに、フッ化ビニリデン(VDF)50質量部、および酢酸エチル0.25質量部を計量し、モノマー混合物を準備した。上記のコア部乳化重合に続けて、80℃において、上記モノマー混合物を缶内圧力が3.2MPaに維持されるように連続供給し、重合を行った。モノマー添加終了後、缶内圧力が2.5MPaに降圧したところで、シェル部の重合を完了とし、フッ化ビニリデン重合体(b-1)からなるシェル部を形成し、コアシェル型の重合体粒子4を得た。得られた粒子の平均粒子径は153nmであった。
オートクレーブに、イオン交換水330質量部、リン酸水素二ナトリウム0.2質量部を入れ、30分間の窒素バブリングによって脱気を行った。次に、パーフルオロオクタン酸アンモニウム塩(PFOA)1.0質量部を仕込み、4.5MPaまで加圧して窒素置換を3回行った。フッ化ビニリデン(VDF)18.0質量部とヘキサフルオロプロピレン(HFP)7.0質量部を、上記オートクレーブ中に一括添加した。これを撹拌しながら80℃に昇温後、5質量%過硫酸アンモニウム(APS)水溶液を、APS換算で0.06質量部に相当する量を入れて、重合を開始した。この時の缶内圧力は、2.6MPa であった。反応開始後、2.5MPaまで圧力が降下したところで、フッ化ビニリデン(VDF)75.0質量部を、缶内圧力が2.5MPaで維持するように連続添加した。圧力が1.5MPaまで低下したところで重合を終了し、フッ化ビニリデン共重合体(a-5)からなる重合体粒子5を得た。得られた粒子の平均粒子径は146nmであった。
(1)PVDF/HFP共重合体の調製
内容量14リットルのオートクレーブに、イオン交換水8271g、メチルセルロース(信越化学社製、SM-100)1.61g、ジイソプロピルパーオキシジカーボネート(IPP)12.9g、フッ化ビニリデン(VDF)2936g、ヘキサフルオロプロピレン(HFP)290gを仕込み、29℃で重合させた。重合終了後、重合体スラリーを95℃で60分間熱処理した後、脱水、水洗し、さらに80℃で20時間乾燥して、フッ化ビニリデン共重合体(a-6)(フッ化ビニリデン・ヘキサフルオロプロピレン共重合体)からなる重合体粒子6を得た。得られた粒子の平均粒子径は170μmであった。
得られた共重合体(PVDF/HFP)を、NMPに5質量%入れ、室温で撹拌しながら50℃に昇温して、完全に溶解させた。これに、共重合体(PVDF/HFP)に対して1質量%の水酸化リチウムを加え、50℃で3時間撹拌した。この溶液を用いて、重合体粒子6のNMP溶液の濁度および粘度、剥離強度を測定した。
得られた共重合体(PVDF/HFP)を、アセトンに10質量%入れ、室温で撹拌しながら分散させ、その後、ウォーターバス中で45℃に昇温して、溶解させた。これに、共重合体(PVDF/HFP)に対して1質量%の水酸化リチウムを加え、50℃で3時間撹拌した。この溶液を用いて、重合体粒子6のアセトン溶液の濁度および粘度を測定した。
オートクレーブにイオン交換水330質量部、中性バッファとしてリン酸水素二ナトリウム0.25質量部を入れ、30分間の窒素バブリングによって脱気を行った。次に、パーフルオロオクタン酸アンモニウム塩(PFOA)1.0質量部を仕込み、4.5MPaまで加圧して窒素置換を3回行った。酢酸エチル0.2質量部、フッ化ビニリデン(VDF)24.7質量部とヘキサフルオロプロピレン(HFP)10.0質量部を上記オートクレーブ中に一括添加した。撹拌下で80℃に昇温後、5質量%過硫酸アンモニウム(APS)水溶液をAPS換算で0.06質量部に相当する量を入れて重合を開始した。反応開始後、圧力が2%以上低下した後に、パーフルオロジビニルエーテル(PFDVE)2質量部とフッ化ビニリデン(VDF)63.3質量部とを缶内圧力が一定になるように連続添加した。圧力が1.5MPaまで低下したところで重合を終了し、フッ化ビニリデン共重合体(a-7)からなる重合体粒子7を得た。得られた粒子の平均粒子径は154nmであった。
内容量14リットルのオートクレーブに、イオン交換水8230g、メチルセルロース(信越化学社製、SM-100)0.96g、ジ-n-プロピルパーオキシジカーボネート27.48g、フッ化ビニリデン(VDF)3146g、およびヘキサフルオロプロピレン(HFP)64gを仕込み、29℃で重合させた。重合終了後、重合体スラリーを95℃で60分間熱処理した後、脱水、水洗し、さらに80℃で20時間乾燥させて、フッ化ビニリデン共重合体(c-1)(フッ化ビニリデン・ヘキサフルオロプロピレン共重合体)からなる重合体粒子8を得た。得られた粒子の平均粒子径は173μmであった。
オートクレーブにイオン交換水330質量部、リン酸水素二ナトリウム0.2質量部を入れ、30分間の窒素バブリングによって脱気を行った。次に、パーフルオロオクタン酸アンモニウム塩(PFOA)0.7質量部を仕込み、4.5MPaまで加圧して窒素置換を3回行った。フッ化ビニリデン(VDF)8.0質量部とヘキサフルオロプロピレン(HFP)47.0質量部を、上記オートクレーブ中に一括添加した。これを撹拌しながら80℃に昇温後、5質量%過硫酸アンモニウム(APS)水溶液を、APS換算で0.06質量部に相当する量を入れて、重合を開始した。この時の缶内圧力は、3.83MPa であった。反応開始後、2.5MPaまで圧力が降下したところで、フッ化ビニリデン(VDF)45.0質量部を、缶内圧力が2.5MPaで維持するように連続添加した。圧力が1.5MPaまで低下したところで重合を終了し、フッ化ビニリデン共重合体(c-2)からなる重合体粒子9を得た。得られた粒子の平均粒子径は187nmであった。
内容量14リットルのオートクレーブに、イオン交換水8271g、メチルセルロース(信越化学社製、SM-100)1.61g、ジイソプロピルパーオキシジカーボネート12.9g、フッ化ビニリデン2903g、ヘキサフルオロプロピレン323gを仕込み、29℃で重合した。重合終了後、重合体スラリーを95℃で60分間熱処理した後、脱水、水洗し、さらに80℃で20時間乾燥して、フッ化ビニリデン共重合体(c-3)(フッ化ビニリデン・ヘキサフルオロプロピレン共重合体)からなる重合体粒子10を得た。得られた粒子の平均粒子径は165μmであった。
オートクレーブに、イオン交換水330質量部、リン酸水素二ナトリウム0.2質量部を入れ、30分間の窒素バブリングによって脱気を行った。次に、パーフルオロオクタン酸アンモニウム塩(PFOA)1.0質量部を仕込み、4.5MPaまで加圧して窒素置換を3回行った。酢酸エチル0.25質量部、フッ化ビニリデン(VDF)23.7質量部とヘキサフルオロプロピレン(HFP)8質量部を、上記オートクレーブ中に一括添加した。これを撹拌しながら80℃に昇温後、5質量%過硫酸アンモニウム(APS)水溶液を、APS換算で0.06質量部に相当する量を入れて、重合を開始した。この時の缶内圧力は、3.3MPaであった。反応開始後、2.5MPaまで圧力が降下したところで、パーフルオロジビニルエーテル(PFDVE)を5質量部投入し、その後、フッ化ビニリデン(VDF)63.3質量部を、缶内圧力が2.5MPaで維持するように連続添加した。圧力が1.5MPaまで低下したところで重合を終了し、フッ化ビニリデン共重合体(c-4)からなる重合体粒子11を得た。得られた粒子の平均粒子径は、152nmであった。
オートクレーブにイオン交換水330質量部、リン酸水素二ナトリウム0.2質量部を入れ、30分間の窒素バブリングによって脱気を行った。次に、パーフルオロオクタン酸アンモニウム塩(PFOA)1.0質量部を仕込み、4.5MPaまで加圧して窒素置換を3回行った。酢酸エチル0.25質量部、フッ化ビニリデン(VDF)28.7質量部とヘキサフルオロプロピレン(HFP)8.0質量部を上記オートクレーブ中に一括添加した。撹拌下で80℃に昇温後、5質量%過硫酸アンモニウム(APS)水溶液をAPS換算で0.06質量部に相当する量を入れて、重合を開始した。この時の缶内圧力は、3.83MPaであった。反応開始後、2.5MPaまで圧力が降下したところで、フッ化ビニリデン(VDF)63.3質量部を、缶内圧力が2.5MPaで維持するように連続添加した。圧力が1.5MPaまで低下したところで重合を終了し、フッ化ビニリデン共重合体(c-5)からなる重合体粒子12を得た。得られた粒子の平均粒子径は187nmであった。
オートクレーブにイオン交換水250質量部、中性バッファであるピロリン酸ナトリウム0.2質量部を入れ、30分間窒素バブリングによって脱気を行った。次に、パーフルオロオクタン酸アンモニウム塩(PFOA)1.0質量部を仕込み、4.5MPaまで加圧して窒素置換を3回行った。酢酸エチル0.5質量部、フッ化ビニリデン(VDF)80質量部、クロロトリフルオロエチレン(CTFE)20質量部、パーフルオロジビニルエーテル(PFDVE)1質量部をモノマー用チャージポットに入れた。このモノマー混合物の一部20質量部を上記オートクレーブ中に一括添加した。これを撹拌しながら、80℃に昇温後、5質量%過硫酸アンモニウム(APS)水溶液を、APS換算で0.08質量部に相当する量を入れて、重合を開始した。反応開始後、ただちに残りのモノマー混合物80質量部を圧力が一定に維持するように連続添加した。圧力が1.3MPaまで低下したところで重合を終了し、フッ化ビニリデン共重合体(c-6)からなる重合体粒子13を得た。得られた粒子の平均粒子径は154nmであった。
(1)コア部の重合
オートクレーブにイオン交換水333質量部、中性バッファであるピロリン酸ナトリウム0.53質量部を入れ、30分間窒素バブリングによって脱気を行った。次に、パーフルオロオクタン酸アンモニウム塩(PFOA)1.33質量部を仕込み、4.5MPaまで加圧して窒素置換を3回行った。酢酸エチル0.53質量部、フッ化ビニリデン(VDF)18質量部、クロロトリフルオロエチレン(CTFE)12質量部、パーフルオロジビニルエーテル(PFDVE)0.3質量部をモノマー用チャージポットに入れた。このモノマー混合物の一部27質量部を上記オートクレーブ中に一括添加した。これを撹拌しながら、80℃に昇温後、5質量%過硫酸アンモニウム(APS)水溶液を、APS換算で0.07質量部に相当する量を入れて、重合を開始した。反応開始後、ただちに残りのモノマー混合物3質量部を圧力が2.6MPaに維持するように連続添加した。圧力が1.5MPaまで低下したところで重合を終了し、フッ化ビニリデン共重合体(a-8)からなるコア部の乳化重合を終了した。得られた粒子の平均粒径は88nmであった。
予め、モノマーチャージ用ポットに、フッ化ビニリデン(VDF)70質量部、および酢酸エチル0.35質量部を計量し、モノマー混合物を準備した。上記のコア部乳化重合に続けて、80℃において、上記モノマー混合物を缶内圧力が3.2MPaに維持されるように連続供給し、重合を行った。モノマー添加終了後、缶内圧力が2.7MPaに降圧したところで、シェル部の重合を完了とした。そして、40℃まで冷却後、残存モノマーをパージし、フッ化ビニリデン重合体(b-2)からなるシェル部を形成し、コアシェル型の重合体粒子14を得た。得られた粒子の平均粒子径は133nmであった。
オートクレーブにイオン交換水330質量部、中性バッファとしてリン酸水素二ナトリウム0.2質量部を入れ、30分間の窒素バブリングによって脱気を行った。次に、パーフルオロオクタン酸アンモニウム塩(PFOA)1.0質量部を仕込み、4.5MPaまで加圧して窒素置換を3回行った。酢酸エチル0.25質量部、フッ化ビニリデン(VDF)27.7質量部とヘキサフルオロプロピレン(HFP)8.0質量部を上記オートクレーブ中に一括添加した。撹拌下で80℃に昇温後、5wt%過硫酸アンモニウム(APS)水溶液をAPS換算で0.1質量部に相当する量を入れて重合を開始した。この時の缶内圧力は3.5MPaであった。反応開始後、2.5MPaまで圧力が降下したところで、パーフルオロジビニルエーテル(PFDVE)を1質量部投入し、その後、フッ化ビニリデン63.3質量部を缶内圧力が2.5MPaで維持するように連続添加した。圧力が1.5MPaまで低下したところで重合を終了し、フッ化ビニリデン共重合体(c-7)からなる重合体粒子15を得た。得られた粒子の平均粒子径は98nmであった。
(1)コア部の重合
オートクレーブに、イオン交換水330質量部を入れ、30分間の窒素バブリングによって脱気を行った。次に、パーフルオロオクタン酸アンモニウム塩(PFOA)1.0質量部を仕込み、4.5MPaまで加圧して窒素置換を3回行った。酢酸エチル0.05質量部、フッ化ビニリデン(VDF)10質量部、およびヘキサフルオロプロピレン(HFP)30質量部を、上記オートクレーブ中に一括添加した。これを撹拌しながら、80℃に昇温後、5質量%過硫酸アンモニウム(APS)水溶液を、APS換算で0.1質量部に相当する量を入れて、重合を開始した。この時の缶内圧力は2.5MPaであった。反応開始後、2.0MPaまで圧力が降下したところで、フッ化ビニリデン(VDF)60質量部を、缶内圧力が2.0MPaで維持するように連続添加した。圧力が1.5MPaまで低下したところで重合を終了し、フッ化ビニリデン共重合体(a-9)からなるコア部の粒子を得た。得られた粒子の平均粒子径は160nmであった。
オートクレーブにイオン交換水700質量部、リン酸水素二ナトリウム0.5質量部を入れ、30分間の窒素バブリングによって脱気を行った。次に、水分散したコア部の粒子100質量部、PFOA0.5質量部を仕込み、4.5MPaまで加圧して窒素置換を3回行った。酢酸エチル0.05質量部、フッ化ビニリデン(VDF)100質量部を上記オートクレーブ中に一括添加した。撹拌下で80℃に昇温後、5wt%APS水溶液をAPS換算で0.1質量部に相当する量を入れて重合を開始した。この時の缶内圧力は4.0MPaであった。反応開始後、1.5MPaまで圧力が降下したところでシェル部の重合を完了とし、フッ化ビニリデン共重合体(b-1)からなるシェル部を形成し、コアシェル型の重合体粒子16を得た。得られた粒子の平均粒子径は203nmであった。
オートクレーブに、イオン交換水330質量部を入れ、30分間の窒素バブリングによって脱気を行った。次に、パーフルオロオクタン酸アンモニウム塩(PFOA)0.7質量部を仕込み、4.5MPaまで加圧して窒素置換を3回行った。酢酸エチル0.1質量部、フッ化ビニリデン(VDF)14.7質量部、およびヘキサフルオロプロピレン(HFP)22質量部を、上記オートクレーブ中に一括添加した。これを撹拌しながら、80℃に昇温後、5質量%過硫酸アンモニウム(APS)水溶液を、APS換算で0.06質量部に相当する量を入れて、重合を開始した。この時の缶内圧力は3.7MPaであった。反応開始後、2.5MPaまで圧力が降下したところで、フッ化ビニリデン(VDF)63.3質量部を、缶内圧力が2.5MPaで維持するように連続添加した。圧力が1.5MPaまで低下したところで重合を終了し、フッ化ビニリデン共重合体(a-10)からなる重合体粒子17を得た。得られた粒子の平均粒子径は175nmであった。
オートクレーブに、イオン交換水330質量部を入れ、30分間の窒素バブリングによって脱気を行った。次に、パーフルオロオクタン酸アンモニウム塩(PFOA)0.7質量部を仕込み、4.5MPaまで加圧して窒素置換を3回行った。酢酸エチル0.1質量部、フッ化ビニリデン(VDF)9.7質量部、およびヘキサフルオロプロピレン(HFP)27質量部を、上記オートクレーブ中に一括添加した。これを撹拌しながら、80℃に昇温後、5質量%過硫酸アンモニウム(APS)水溶液を、APS換算で0.06質量部に相当する量を入れて、重合を開始した。この時の缶内圧力は3.7MPaであった。反応開始後、2.5MPaまで圧力が降下したところで、フッ化ビニリデン(VDF)63.3質量部を、缶内圧力が2.5MPaで維持するように連続添加した。圧力が1.5MPaまで低下したところで重合を終了し、フッ化ビニリデン共重合体(a-11)からなる重合体粒子18を得た。得られた粒子の平均粒子径は183nmであった。
オートクレーブに、イオン交換水330質量部を入れ、30分間の窒素バブリングによって脱気を行った。次に、パーフルオロオクタン酸アンモニウム塩(PFOA)0.7質量部を仕込み、4.5MPaまで加圧して窒素置換を3回行った。酢酸エチル0.1質量部、フッ化ビニリデン(VDF)9.5質量部、およびヘキサフルオロプロピレン(HFP)27.3質量部を、上記オートクレーブ中に一括添加した。これを撹拌しながら、80℃に昇温後、5質量%過硫酸アンモニウム(APS)水溶液を、APS換算で0.06質量部に相当する量を入れて、重合を開始した。この時の缶内圧力は2.6MPaであった。反応開始後ただちに、フッ化ビニリデン(VDF)63.4質量部を、缶内圧力が2.6MPaで維持するように連続添加した。圧力が1.5MPaまで低下したところで重合を終了し、フッ化ビニリデン共重合体(c-8)からなる重合体粒子19を得た。得られた粒子の平均粒子径は213nmであった。
得られた重合体粒子の融点は、フィルムの形態で測定した。フィルムは、以下の方法で作製した。すなわち、剥離剤を噴霧した2枚のアルミ箔の間に、縦5cm×横5cm×厚み150μmの鋳型と重合体粒子約1gを挟み、200℃でプレスした。得られたフィルムを用いて、フッ化ビニリデン共重合体の融点を、DSC(METTLER社製「DSC-1」)を用いてASTM d 3418に準拠して測定した。
(アセトン溶液の調製)
得られた重合体粒子を、アセトンに溶解させた。具体的には、重合体粒子を、溶液中のポリマー濃度が10質量%になるように添加し、常温でアセトン中に分散させた後、45℃のウォーターバス中で撹拌して、フッ化ビニリデン共重合体を溶解させた。
得られたアセトン溶液の粘度を、E型粘度計で測定した。具体的には、アセトン溶液1.1mlを粘度計(東機産業株式会社製RE550型粘度計)の測定部に入れ、コーンロータ1°34‘×R24、回転数10rpm、測定時間300秒、測定温度25℃で測定を行った。300秒経過時点での粘度をアセトン溶液粘度とした。
(NMP溶液の調製)
得られた重合体粒子を、NMPに溶解させた。具体的には、重合体粒子を、溶液中のポリマー濃度が5質量%になるように添加し、常温でNMP中に分散させた後、ホットスターラーを用いて50℃で撹拌して、当該重合体粒子を溶解させた。
(NMP溶液の調製)
前述と同様の方法で、NMP溶液を得た。
得られたNMP溶液の粘度を、前述のアセトン溶液の溶液粘度(A)の測定方法と同様の方法で測定した。
懸濁重合法で得られた重合体粒子(重合体粒子6、8および10)について、インヘレント粘度を測定した。具体的には、得られた重合体粒子80mgを、20mLのDMFに溶解させて、溶液を得た。得られた溶液とDMFのそれぞれについて、30℃の恒温槽内における粘度を、ウベローテ粘度計を用いて測定し、以下の式によりインヘレント粘度を算出した。
ηi=(1/C)・ln(η/η0)
ηは、測定された溶液の粘度、η0は、測定されたDMFの粘度、Cは、溶液におけるフッ化ビニリデン共重合体を含む粒子の濃度であり、ここでは0.4(g/dl)である。
乳化重合法で得られた重合体粒子(重合体粒子1~5、7、9および11~19)について、平均粒子径を動的光散乱法の正則化解析によって算出した。具体的には、BECKMAN COULTER社製「DelsaMaxCORE」を使用し、JIS Z 8828に準拠して重合体粒子の粒子径を測定し、正則化解析によって得られる大小2つのピークのうち、大きいピークを平均粒子径とした。
一方、懸濁重合によって重合体粒子を得た場合は、粉体化した重合体粒子3000個を撮影し、撮影された各粒子が円形であったと仮定した場合の粒子の粒径の平均値を平均粒径とした。
〔実施例1~10、比較例1~9〕
表1および2に示される重合体粒子(接着性樹脂粒子)を、溶液中のポリマー濃度が5質量%になるようにNMPに分散させて、接着性樹脂組成物を得た。
(1)セパレータ構造体の作製
接着性樹脂組成物を、セパレータ(ポリエチレン製単層セパレータ、厚み20μm、気孔度40%、透気度300sec、引張強度(MD)150MPa、(TD)130MPa、引張伸度(MD)50%、(TD)100%)の片面に、ウェット塗布量24μm(番手12)のワイヤーバーを用いて、塗布した後、23±2℃の凝固浴(水)に3分間浸漬した。その後、洗浄液(水)に1分間浸漬し、70℃で30分間、窒素下で乾燥させた。さらに、60℃で3時間、真空中で熱処理して、厚み2μmの接着性樹脂組成物層を有するセパレータ構造体を得た。
負極活物質としてBTR918(改質天然黒鉛 BTR製)95質量部、導電助剤(SuperP TIMCAL製)2質量部、結着剤としてSBR(スチレンブタジエンゴム)ラテックス(BM-400 日本ゼオン製)2質量部、増粘剤としてCMC(カルボキシメチルセルロース)(セロゲン4H 第一工業製薬製)1質量部に水を加えてスラリーを作製し、銅箔(厚さ10μm)に塗布した。塗布したスラリーを乾燥させた後、プレスし、150℃で3時間熱処理した。これにより、電極嵩密度が1.6g/cm3、目付け量が60g/m2の負極活物質層を形成し、負極を得た。
得られた負極を、2.5×5.0cmに切り出した。また、上記作製したセパレータを3.0×6.0cmに切り出した。得られた負極とセパレータとを積層し、Alラミネートフィルムの袋に入れた。Alラミネートフィルムの袋に入れた当該積層物に、電解液(エチレンカーボネート(EC)/エチルメチルカーボネート(EMC)=3/7(質量比)、LiPF6:1.2M、VC:1質量%)を180μL注入し、浸み込ませた後、真空脱気して封止し、一晩静置した。
得られたAlラミネートセルを熱プレスして、セパレータ上の接着性樹脂組成物層と負極とを熱融着させて、剥離強度測定用サンプルを得た。具体的には、得られたAlラミネートセルを、1分間予熱した後、50℃で2分間、面圧約4MPaで熱プレスして、以下の方法で剥離強度を測定した。
そして、熱プレス温度を50~110℃の範囲で変えて、同様の測定を繰り返した。具体的には、各熱プレス温度ごとに3つのサンプルを準備して剥離強度を測定し、それらの平均値を「各熱プレス温度での剥離強度」とした。そして、熱プレス温度を50~110℃の範囲で変えて同様の測定を繰り返したときの、「各熱プレス温度での剥離強度」の最大値を「剥離強度」とした。
剥離強度測定用サンプルの作製と同様にして、Alラミネートセルを作製した。得られたAlラミネートセルを、任意の温度で1分間の余熱した後、2分間、面圧約4MPaで熱プレスして、セパレータ上の接着性樹脂組成物層と負極とを熱融着させて、剥離強度測定用サンプルを得た。得られた剥離強度測定用サンプルについて、前述と同様の方法で剥離強度を測定した。これらの一連の操作を、熱プレス温度を50~110℃の範囲で段階的に高くしながら繰り返し行い、剥離強度が1.0gf/mm以上となる温度域(接着可能温度域、プロセスウィンドウ)を求めた。
Claims (15)
- 非水電解質二次電池のセパレータまたは電極の表面に設けられる、接着性樹脂を含む接着性組成物であって、
前記接着性樹脂は、フッ化ビニリデンに由来する構成単位と、前記フッ化ビニリデンと共重合可能な単量体に由来する構成単位とを含むフッ化ビニリデン共重合体(a)を少なくとも1種含み、
前記接着性樹脂を、溶液中の濃度が5質量%となるようにN-メチル-2-ピロリドンに溶解させたときの濁度が2以上95以下であり、かつ前記接着性樹脂を、溶液中の濃度が10質量%となるようにアセトンに溶解させたときの溶液粘度(A)が350~20000mPa・sであり、
前記接着性樹脂を、溶液中の濃度が5質量%となるようにN-メチル-2-ピロリドンに溶解させたときの溶液粘度(B)に対する前記溶液粘度(A)の比(A)/(B)が1以上15以下である、
接着性組成物。 - 前記接着性樹脂は、前記フッ化ビニリデン共重合体(a)を含む粒子であり、
前記粒子の平均粒子径は、10nm~1μmである、
請求項1に記載の接着性組成物。 - 前記粒子は、前記フッ化ビニリデン共重合体(a)からなるコア部と、前記コア部の周囲を取り囲み、かつ前記コア部よりもフッ化ビニリデンの比率が高いフッ化ビニリデン重合体(b)からなるシェル部とを含むコアシェル型粒子であり、
前記コアシェル型粒子に含まれる全てのモノマー量を100質量%としたとき、前記フッ化ビニリデンの含有量は97質量%以下である、
請求項2に記載の接着性組成物。 - 前記フッ化ビニリデン共重合体(a)は、架橋されていない、
請求項3に記載の接着性組成物。 - 前記フッ化ビニリデン重合体(b)は、架橋されていない、
請求項3または4に記載の接着性組成物。 - 前記フッ化ビニリデン重合体(b)は、カルボキシル基含有モノマーに由来する構造単位をさらに含む、
請求項3~5のいずれか一項に記載の接着性組成物。 - 前記フッ化ビニリデンと共重合可能な単量体は、クロロトリフルオロエチレンおよびヘキサフルオロプロピレンの少なくとも一方である、
請求項1~6のいずれか一項に記載の接着性組成物。 - 前記接着性樹脂の融点は、90℃以上である、
請求項1~7のいずれか一項に記載の接着性組成物。 - セパレータと、
その少なくとも一方の表面に設けられた、請求項1~8のいずれか一項に記載の接着性組成物を用いて得られる接着性組成物層とを有する、
セパレータ構造体。 - 集電体と、前記集電体上に設けられた電極活物質を含む電極活物質層とを有する電極と、
前記電極活物質層の表面に設けられた、請求項1~8のいずれか一項に記載の接着性組成物を用いて得られる接着性組成物層とを有する、
電極構造体。 - 正極と、負極と、それらの間に配置されたセパレータと、前記セパレータと前記正極との間および前記セパレータと前記負極との間の少なくとも一方に設けられた、請求項1~8のいずれか一項に記載の接着性組成物を用いて得られる接着性組成物層とを有する、
非水電解質二次電池。 - 正極と、負極と、それらの間に配置されたセパレータと、前記セパレータと前記正極との間および前記セパレータと前記負極との間の少なくとも一方に設けられた、請求項1~8のいずれか一項に記載の接着性組成物を用いて得られる接着性組成物層とを有する積層物を得る工程と、
前記積層物を、前記接着性組成物を介して前記セパレータと前記正極とを接着させ、および/または、前記セパレータと前記負極とを接着させる工程とを含む、
非水電解質二次電池の製造方法。 - 前記接着させる工程は、40~180℃で加熱することにより行われる、
請求項12の非水電解質二次電池の製造方法。 - 前記接着させる工程は、40~180℃の熱プレスにより行われる、
請求項12の非水電解質二次電池の製造方法。 - 前記接着させる工程は、前記積層物に電解液を含浸させた後に行う、請求項12~14のいずれか一項に記載の非水電解質二次電池の製造方法。
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR1020207035278A KR102260002B1 (ko) | 2018-05-31 | 2019-04-15 | 접착성 조성물, 세퍼레이터 구조체, 전극 구조체, 비수 전해질 이차 전지 및 이의 제조방법 |
JP2020521772A JP6891346B2 (ja) | 2018-05-31 | 2019-04-15 | 接着性組成物、セパレータ構造体、電極構造体、非水電解質二次電池およびその製造方法 |
CN201980031083.1A CN112088457B (zh) | 2018-05-31 | 2019-04-15 | 粘接性组合物、隔离件结构体、电极结构体、非水电解质二次电池及其制造方法 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2018104685 | 2018-05-31 | ||
JP2018-104685 | 2018-05-31 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2019230219A1 true WO2019230219A1 (ja) | 2019-12-05 |
Family
ID=68698020
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2019/016153 WO2019230219A1 (ja) | 2018-05-31 | 2019-04-15 | 接着性組成物、セパレータ構造体、電極構造体、非水電解質二次電池およびその製造方法 |
Country Status (4)
Country | Link |
---|---|
JP (1) | JP6891346B2 (ja) |
KR (1) | KR102260002B1 (ja) |
CN (1) | CN112088457B (ja) |
WO (1) | WO2019230219A1 (ja) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN112159634A (zh) * | 2020-09-16 | 2021-01-01 | 四川星明能源环保科技有限公司 | 碳粉导电胶、利用碳粉导电胶制备的液流电池电极及电堆 |
CN113113721A (zh) * | 2021-03-18 | 2021-07-13 | 清华大学 | 电池隔膜及其制备方法、电池 |
WO2022030279A1 (ja) * | 2020-08-07 | 2022-02-10 | 株式会社豊田自動織機 | 蓄電装置 |
CN114497891A (zh) * | 2021-12-29 | 2022-05-13 | 惠州锂威电子科技有限公司 | 一种二次电池用隔膜及其制备方法、二次电池 |
EP4167332A1 (en) * | 2021-10-15 | 2023-04-19 | Samsung SDI Co., Ltd. | Electrode assembly and rechargeable lithium battery including the same |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR20240116756A (ko) * | 2021-12-28 | 2024-07-30 | 가부시끼가이샤 구레하 | 접착제, 전극 조성물, 및 전극 |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002025620A (ja) * | 2000-07-12 | 2002-01-25 | Japan Storage Battery Co Ltd | 非水電解質二次電池 |
JP2013020769A (ja) * | 2011-07-08 | 2013-01-31 | Teijin Ltd | 非水電解質電池用セパレータ及び非水電解質電池 |
WO2013058371A1 (ja) * | 2011-10-21 | 2013-04-25 | 帝人株式会社 | 非水系二次電池用セパレータ及び非水系二次電池 |
JP2018172595A (ja) * | 2017-03-31 | 2018-11-08 | 株式会社クレハ | コアシェル型粒子ならびにその用途および製造方法 |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5626791B2 (ja) * | 2008-12-26 | 2014-11-19 | 株式会社クレハ | 非水電解質二次電池用負極合剤、非水電解質二次電池用負極および非水電解質二次電池 |
US9059448B2 (en) * | 2009-01-19 | 2015-06-16 | Toray Industries, Inc. | Process for producing polymeric electrolyte membrane |
CN103588921B (zh) * | 2012-08-14 | 2016-04-27 | 中化蓝天集团有限公司 | 一种高粘度自交联偏氟乙烯共聚物、其制备方法及应用 |
WO2014046078A1 (ja) * | 2012-09-18 | 2014-03-27 | 株式会社クレハ | 非水電解質二次電池用バインダー、非水電解質二次電池用バインダー溶液、非水電解質二次電池用負極合剤およびその用途 |
JP6087684B2 (ja) | 2013-03-25 | 2017-03-01 | 大同メタル工業株式会社 | 摺動部材及び摺動部材の製造方法 |
US20150360409A1 (en) * | 2014-06-16 | 2015-12-17 | Nano And Advanced Materials Institute Limited | Flexible porous film |
EP3339394B1 (en) * | 2016-12-22 | 2018-12-12 | Avantama AG | Luminescent composite materials |
-
2019
- 2019-04-15 JP JP2020521772A patent/JP6891346B2/ja active Active
- 2019-04-15 WO PCT/JP2019/016153 patent/WO2019230219A1/ja active Application Filing
- 2019-04-15 KR KR1020207035278A patent/KR102260002B1/ko active IP Right Grant
- 2019-04-15 CN CN201980031083.1A patent/CN112088457B/zh active Active
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002025620A (ja) * | 2000-07-12 | 2002-01-25 | Japan Storage Battery Co Ltd | 非水電解質二次電池 |
JP2013020769A (ja) * | 2011-07-08 | 2013-01-31 | Teijin Ltd | 非水電解質電池用セパレータ及び非水電解質電池 |
WO2013058371A1 (ja) * | 2011-10-21 | 2013-04-25 | 帝人株式会社 | 非水系二次電池用セパレータ及び非水系二次電池 |
JP2018172595A (ja) * | 2017-03-31 | 2018-11-08 | 株式会社クレハ | コアシェル型粒子ならびにその用途および製造方法 |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2022030279A1 (ja) * | 2020-08-07 | 2022-02-10 | 株式会社豊田自動織機 | 蓄電装置 |
JP2022030965A (ja) * | 2020-08-07 | 2022-02-18 | 株式会社豊田自動織機 | 蓄電装置 |
JP7334693B2 (ja) | 2020-08-07 | 2023-08-29 | 株式会社豊田自動織機 | 蓄電装置 |
CN112159634A (zh) * | 2020-09-16 | 2021-01-01 | 四川星明能源环保科技有限公司 | 碳粉导电胶、利用碳粉导电胶制备的液流电池电极及电堆 |
CN113113721A (zh) * | 2021-03-18 | 2021-07-13 | 清华大学 | 电池隔膜及其制备方法、电池 |
CN113113721B (zh) * | 2021-03-18 | 2022-05-20 | 清华大学 | 电池隔膜及其制备方法、电池 |
EP4167332A1 (en) * | 2021-10-15 | 2023-04-19 | Samsung SDI Co., Ltd. | Electrode assembly and rechargeable lithium battery including the same |
CN114497891A (zh) * | 2021-12-29 | 2022-05-13 | 惠州锂威电子科技有限公司 | 一种二次电池用隔膜及其制备方法、二次电池 |
CN114497891B (zh) * | 2021-12-29 | 2024-02-20 | 惠州锂威电子科技有限公司 | 一种二次电池用隔膜及其制备方法、二次电池 |
Also Published As
Publication number | Publication date |
---|---|
KR102260002B1 (ko) | 2021-06-02 |
CN112088457B (zh) | 2021-12-03 |
CN112088457A (zh) | 2020-12-15 |
JPWO2019230219A1 (ja) | 2020-12-17 |
JP6891346B2 (ja) | 2021-06-18 |
KR20200141530A (ko) | 2020-12-18 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
KR102369813B1 (ko) | 이차 전지용 결착제, 이차 전지용 전극 합제, 이차 전지용 전극 및 이차 전지 | |
JP6891346B2 (ja) | 接着性組成物、セパレータ構造体、電極構造体、非水電解質二次電池およびその製造方法 | |
JP5757363B1 (ja) | 二次電池用セパレータ及び二次電池 | |
KR102401458B1 (ko) | 2차 전지 정극용 바인더 조성물, 2차 전지 정극용 슬러리 조성물, 2차 전지용 정극 및 2차 전지 | |
CN110088943B (zh) | 核壳型粒子及其用途以及制造方法 | |
KR102231591B1 (ko) | 코어 쉘형 입자 및 이의 용도 및 제조 방법 | |
KR102219159B1 (ko) | 불화 비닐리덴 공중합체 입자 및 이의 이용 | |
JP2018195552A (ja) | 二次電池用結着剤及び二次電池用電極合剤 | |
JP6960051B2 (ja) | ポリマー溶液、これを用いたフィルムの製造方法、および非水電解質二次電池用樹脂組成物 | |
US10074841B2 (en) | Structure for non-aqueous electrolyte secondary battery, non-aqueous electrolyte secondary battery, and method for manufacturing same structure | |
JPWO2006080259A1 (ja) | フッ化ビニリデン系コア/シェル型重合体およびその非水系電気化学素子における利用 | |
JP2016062835A (ja) | 水性ラテックス、セパレータ/中間層積層体、及び非水電解質二次電池用構造体 | |
WO2019230075A1 (ja) | 非水電解質二次電池用樹脂組成物、ならびにこれを用いた非水電解質二次電池用セパレータ、電極合剤層用樹脂組成物、非水電解質二次電池用電極、および非水電解質二次電池 | |
KR20240004687A (ko) | 플루오로폴리머 결합제 | |
CN115702173B (zh) | 用于锂离子蓄电装置的电极粘合剂组合物 | |
JP7209813B2 (ja) | 非フッ素化界面活性剤を用いたフッ化ビニリデン系重合体組成物及びその製造方法 | |
JP2019071294A (ja) | 水性ラテックス、セパレータ/中間層積層体、及び非水電解質二次電池用構造体 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 19811479 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2020521772 Country of ref document: JP Kind code of ref document: A |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
ENP | Entry into the national phase |
Ref document number: 20207035278 Country of ref document: KR Kind code of ref document: A |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 19811479 Country of ref document: EP Kind code of ref document: A1 |