WO2009123218A1 - 電池用セパレータとこれを用いてなる電池 - Google Patents
電池用セパレータとこれを用いてなる電池 Download PDFInfo
- Publication number
- WO2009123218A1 WO2009123218A1 PCT/JP2009/056720 JP2009056720W WO2009123218A1 WO 2009123218 A1 WO2009123218 A1 WO 2009123218A1 JP 2009056720 W JP2009056720 W JP 2009056720W WO 2009123218 A1 WO2009123218 A1 WO 2009123218A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- battery
- separator
- polymer
- electrode
- crosslinked polymer
- 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
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
- H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
- H01M10/0565—Polymeric materials, e.g. gel-type or solid-type
-
- 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
-
- 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
- H01M10/36—Accumulators not provided for in groups H01M10/05-H01M10/34
- H01M10/38—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
- 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
- H01M50/417—Polyolefins
-
- 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
- H01M50/451—Separators, membranes or diaphragms characterised by the material having a layered structure comprising layers of only organic material and layers containing inorganic 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
- H01M50/46—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
- H01M50/491—Porosity
-
- 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
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- 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
- H01M2300/00—Electrolytes
- H01M2300/0085—Immobilising or gelification of electrolyte
-
- 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
-
- 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
-
- 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
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/49108—Electric battery cell making
-
- 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
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/49108—Electric battery cell making
- Y10T29/4911—Electric battery cell making including sealing
Definitions
- the present invention relates to a battery separator and a battery using the same, and more specifically, to a battery separator in which a porous polymer layer having a polycarbonate urethane skeleton is supported on a porous substrate, and using such a separator.
- a battery A battery.
- lithium ion secondary batteries having high energy density are widely used as power sources for small portable electronic devices such as mobile phones and notebook personal computers.
- Such a lithium ion secondary battery is obtained by laminating or winding sheet-like positive and negative electrodes and, for example, a polyolefin resin porous film, and charging it into a battery container made of, for example, a metal can. It is manufactured through a process of injecting an electrolytic solution into a battery container, sealing, and sealing.
- the surface pressure for maintaining the electrical connection between the separator and the electrode cannot be sufficiently applied to the electrode surface as compared with the conventional metal can container. Due to the expansion and contraction of the electrode active material during charging and discharging, the distance between the electrodes partially increases with time, the internal resistance of the battery increases, the battery characteristics deteriorate, and the resistance varies within the battery. However, there arises a problem that the battery characteristics are deteriorated.
- an electrode and a separator are joined by an adhesive resin layer composed of a mixed phase of an electrolyte solution phase, a polymer gel layer containing an electrolyte solution, and a polymer solid phase.
- an adhesive resin layer composed of a mixed phase of an electrolyte solution phase, a polymer gel layer containing an electrolyte solution, and a polymer solid phase.
- the thickness of the adhesive resin layer must be increased, and the electrolytic solution for the adhesive resin Since the amount cannot be increased, the resulting battery has a problem that the internal resistance becomes high and the cycle characteristics and the high rate discharge characteristics cannot be sufficiently obtained.
- the adhesive strength between the separator and the electrode is lowered when placed in a high temperature environment. There is a risk of causing a short circuit between the electrodes due to contraction.
- the adhesive resin is swollen by the electrolytic solution.
- the electrolyte ions are less likely to diffuse into the adhesive resin. Adversely affects properties.
- porous substrates for battery separators various manufacturing methods are conventionally known for porous substrates for battery separators.
- a method of manufacturing a sheet made of a polyolefin resin and stretching the sheet at a high magnification is known (for example, see Patent Document 4).
- the battery separator made of a porous film obtained by stretching at a high magnification in this way is significantly shrunk under a high temperature environment such as when the battery is abnormally heated due to an internal short circuit or the like, and in some cases, There is a problem that it does not function as a partition between electrodes.
- Patent Document 6 a fluororesin porous layer such as polytetrafluoroethylene resin between the separator and the positive electrode.
- a fluororesin porous layer such as polytetrafluoroethylene resin between the separator and the positive electrode
- a method of spraying a polytetrafluoroethylene resin suspension on a separator and drying it is considered preferable.
- the resulting layer is rich in porosity, it becomes thick and sacrifices battery capacity, and requires a large amount of electrolyte.
- Japanese Patent Laid-Open No. 09-161814 Japanese Patent Laid-Open No. 11-329439 Japanese Patent Laid-Open No. 10-172606
- Japanese Patent Laid-Open No. 09-012756 Japanese Patent Laid-Open No. 05-310989 Japanese Patent Laid-Open No. 2007-157459
- the present invention has been made to solve the above-described various problems in battery separators, and in particular, provides a battery separator having excellent oxidation resistance and adhesion to electrodes. Another object is to provide a battery using such a battery separator.
- the present invention relates to the following (1) to (9).
- a battery separator comprising a porous substrate and a layer of a crosslinked polymer supported on at least one surface of the porous substrate,
- the crosslinked polymer is (A) a reactive polymer having a reactive group containing active hydrogen in the molecule; (B) A battery separator obtained by reaction with a terminal isocyanate group polycarbonate urethane prepolymer.
- the reactive group containing active hydrogen is at least one selected from a hydroxy group, a carboxyl group, and an amino group.
- the porous substrate is a polyolefin resin porous film.
- the battery separator of the present invention has a porous polymer supported on a porous substrate obtained by reacting a reactive polymer having a reactive group containing active hydrogen in the molecule with a terminal isocyanate group polycarbonate urethane prepolymer. can get. Therefore, the crosslinked polymer is excellent in oxidation resistance and further has adhesiveness with the electrode.
- an electrode is laminated on such a battery separator to form an electrode / separator laminate, which is charged into the battery container, and then a non-aqueous electrolyte is injected into the battery container to form a porous substrate. It is possible to adhere the electrode to the separator by swelling at least a part of the cross-linked polymer in the vicinity of the interface with the electrode and allowing it to penetrate into the electrode active material together with the electrolytic solution, thus having an electrode / separator assembly. A battery can be obtained.
- the crosslinked polymer since the crosslinked polymer has a crosslinked structure, when it swells in the electrolytic solution, excessive elution and diffusion into the electrolytic solution does not occur and does not adversely affect the electrolytic solution.
- the crosslinked polymer has a high oxidation resistance because the reactive polymer is crosslinked with a terminal isocyanate group polycarbonate urethane prepolymer and includes a polycarbonate structure. Therefore, the battery separator of the present invention carrying such a cross-linked polymer layer has a high resistance to a highly oxidizing environment at the interface with the positive electrode, and thus has a high energy density and charge / discharge. A battery with excellent characteristics can be provided.
- porous substrate In the present invention, a porous substrate having a thickness in the range of 3 to 50 ⁇ m is preferably used.
- the thickness of the porous substrate is less than 3 ⁇ m, the strength is insufficient, and when used as a separator in a battery, the electrode may cause an internal short circuit.
- the thickness of the porous substrate exceeds 50 ⁇ m, the battery using such a porous substrate as a separator has a too large distance between electrodes, and the internal resistance of the battery becomes excessive.
- the porous substrate has pores with an average pore diameter of 0.01 to 5 ⁇ m and a porosity of 20 to 95%. In the range of 30 to 90%, and most preferably in the range of 35 to 85%.
- the porosity is too low, when used as a battery separator, the ion conduction path is reduced, and sufficient battery characteristics cannot be obtained.
- the porosity is too high, the strength is insufficient when used as a battery separator, and a thick porous substrate must be used to obtain the required strength. Therefore, the internal resistance of the battery becomes high, which is not preferable.
- a porous substrate having an air permeability of 1500 seconds / 100 cc or less, preferably 1000 seconds / 100 cc or less is used.
- the strength of the porous substrate is preferably 1 N or more. This is because when the piercing strength is less than 1 N, the porous base material may be broken when a surface pressure is applied between the electrodes, thereby causing an internal short circuit.
- the porous substrate preferably has a high affinity with a reactive polymer, which will be described later. Therefore, when the porous substrate is made of a material having a low polarity, in order to improve the affinity with the reactive polymer. Further, it is preferable to subject the surface to an appropriate surface hydrophilization treatment such as a corona treatment.
- the porous base material is not particularly limited as long as it has the above-described characteristics, but from the viewpoint of solvent resistance and strength, from a polyolefin resin such as polyethylene and polypropylene.
- a porous film is preferred.
- the polyethylene resin porous film is particularly preferably used. It is done.
- the polyethylene resin includes not only a homopolymer of ethylene but also a copolymer of ethylene with an ⁇ -olefin such as propylene, butene and hexene.
- a porous film obtained by using ultrahigh molecular weight polyethylene as the polyethylene is suitably used as the porous substrate.
- Ultra high molecular weight polyethylene refers to polyethylene having a weight average molecular weight of 500,000 or more, preferably in the range of 500,000 to 3,000,000, and various commercial products can be obtained.
- a mixture of ultrahigh molecular weight polyethylene and another resin may be used as the porous film.
- porous films such as polytetrafluoroethylene, polyimide, polyester, polycarbonate, and regenerated cellulose
- paper in addition to porous films such as polytetrafluoroethylene, polyimide, polyester, polycarbonate, and regenerated cellulose, paper can also be used as a porous substrate.
- a porous substrate in which inorganic fillers such as titanium oxide, alumina, and kaolinite and mineral fillers such as montmorillonite are dispersed can also be used.
- the reactive polymer means a polymer having a reactive group containing active hydrogen in the molecule, and the reactive group containing active hydrogen means a group reactive with an isocyanate group by active hydrogen, Examples of such a reactive group include at least one selected from a hydroxy group, a carboxyl group, and an amino group.
- a crosslinked polymer having a polycarbonate urethane skeleton can be obtained by reacting such a reactive polymer with a terminal isocyanate group polycarbonate urethane prepolymer.
- the terminal isocyanate group polycarbonate urethane prepolymer can be obtained by a reaction between a polycarbonate diol and a polyfunctional isocyanate.
- the reactive polymer is preferably a radical obtained by using a radical polymerization initiator and a first radical polymerizable monomer having the reactive group and a second radical polymerizable monomer having no such reactive group. It can be obtained by copolymerization.
- the radical polymerizable monomer having a reactive group is used in the range of 0.1 to 10% by weight, preferably 0.5 to 5% by weight, based on the total amount of monomers.
- the radically polymerizable monomer having a reactive group is less than 0.1% by weight in the total monomer amount, the resulting reactive polymer is reacted with a terminal isocyanate group polycarbonate urethane prepolymer described later to form a crosslinked polymer. Even if such a crosslinked polymer is obtained, the insoluble fraction is too small, and when the electrode / separator laminate is immersed in the electrolytic solution, elution and diffusion of the polymer into the electrolytic solution are not sufficiently suppressed, and elution occurs. The amount of diffusion increases.
- the adhesion between the porous substrate and the electrode cannot be maintained, and the deterioration of the battery may be accelerated by impurities.
- the amount of the radically polymerizable monomer having a reactive group is more than 10% by weight, even if the resulting crosslinked polymer has too high a crosslinking density, the crosslinked polymer becomes excessively dense and comes into contact with the electrolytic solution. Does not swell sufficiently. As a result, an electrode / separator assembly cannot be obtained, and a battery having excellent characteristics cannot be obtained.
- Examples of the first radical polymerizable monomer having the reactive group include those in which the reactive group is a carboxyl group, such as (meth) acrylic acid, itaconic acid, maleic acid, and the like.
- Examples of the hydroxy group include hydroxyalkyl such as 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, and the like.
- (Meth) acrylate ethylene glycol mono (meth) acrylate, diethylene glycol mono (meth) acrylate, triethylene glycol mono (meth) acrylate, hexaethylene glycol mono (meth) acrylate, propylene glycol mono (meth) acrylate
- Poly) alkylene glycol mono (meth) acrylate such as dipropylene glycol mono (meth) acrylate, tripropylene glycol mono (meth) acrylate, pentapropylene glycol mono (meth) acrylate, 2-hydroxyethyl (meth) acrylate And ⁇ -butyrolactone ring-opening adduct.
- the reactive group that is an amino group include a 1: 1 reaction product of diamine and (meth) acryloyloxyethyl isocyanate.
- (meth) acrylic acid means acrylic acid or methacrylic acid
- (meth) acrylate means acrylate or methacrylate
- (meth) acryloyloxy means acryloyloxy or methacryloyloxy.
- the second radical polymerizable monomer having no reactive group is preferably represented by the general formula (I)
- R 1 represents a hydrogen atom or a methyl group
- A represents an oxyalkylene group having 2 or 3 carbon atoms (preferably an oxyethylene group or an oxypropylene group)
- R 2 represents 1 to 6 represents an alkyl group or a fluorinated alkyl group having 1 to 6 carbon atoms
- n represents an integer of 0 to 12.
- R 3 represents a methyl group or an ethyl group
- R 4 represents a hydrogen atom or a methyl group.
- (meth) acrylate represented by the general formula (I) include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2,2,2 -Trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate and the like.
- R 5 represents a hydrogen atom or a methyl group, and n is an integer of 0 to 12.
- vinyl ester represented by the general formula (II) examples include vinyl acetate and vinyl propionate.
- the reactive polymer is obtained by radical copolymerization of the first radical polymerizable monomer having a reactive group and the second radical polymerizable monomer having no reactive group using a radical polymerization initiator.
- This radical copolymerization may be carried out by any polymerization method such as solution polymerization, bulk polymerization, suspension polymerization, emulsion polymerization, etc., but solution polymerization or suspension polymerization in terms of ease of polymerization, adjustment of molecular weight, post-treatment, etc. Is preferred.
- the radical polymerization initiator is not particularly limited, and examples thereof include N, N′-azobisisobutyronitrile, dimethyl N, N′-azobis (2-methylpropionate), and benzoyl peroxide. Lauroyl peroxide is used. In this radical copolymerization, a molecular weight modifier such as mercaptan can be used as necessary.
- the reactive polymer preferably has a weight average molecular weight of 10,000 or more.
- the weight average molecular weight of the reactive polymer is smaller than 10000, the crosslinked polymer obtained therefrom is difficult to swell in the electrolyte solution, and the characteristics of the obtained battery are deteriorated.
- the upper limit of the weight average molecular weight of the reactive polymer is not particularly limited, but is about 3 million, preferably 250 so that the cross-linked polymer obtained therefrom can hold the electrolyte as a gel. It is about ten thousand.
- the reactive polymer preferably has a weight average molecular weight in the range of 100,000 to 2,000,000.
- the terminal isocyanate group polycarbonate urethane prepolymer (hereinafter, simply referred to as urethane prepolymer) is preferably an aliphatic polycarbonate diol and a polyfunctional isocyanate, the isocyanate group of the polyfunctional isocyanate / hydroxy of the polycarbonate diol.
- Oligomer obtained by reacting the group in a molar ratio (hereinafter referred to as NCO / OH molar ratio) usually in the range of 1.2 to 3.3, preferably in the range of 1.5 to 2.5. It is.
- the molecular weight of the urethane prepolymer obtained varies depending on the NCO / OH molar ratio, and when the NCO / OH molar ratio is within the above range, a urethane prepolymer having both ends of the molecule being substantially isocyanate groups is obtained. Can do.
- the aliphatic polycarbonate diol can be obtained, for example, by a reaction between an aliphatic diol and phosgene, ring-opening polymerization of an alkylene carbonate, or the like.
- the polycarbonate diol is obtained by the reaction of an aliphatic diol and phosgene, the aliphatic diol to be used is not particularly limited.
- examples include methylene diol, 1,5-pentamethylene diol, neopentyl glycol, 1,6-hexamethylene diol, and 1,4-cyclohexane diol. These aliphatic diols are used alone or in combination of two or more.
- the alkylene carbonate to be used is not particularly limited, and examples thereof include ethylene carbonate, trimethylene carbonate, tetramethylene carbonate, hexamethylene carbonate and the like. These alkylene carbonates are also used alone or in combination of two or more.
- the aliphatic polycarbonate diol can also be obtained by reacting the above-described alkylene carbonate or dialkyl carbonate with the aliphatic diol.
- dialkyl carbonate include dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, di-n-butyl carbonate and the like.
- the aliphatic polycarbonate diol used is preferably of the general formula (III)
- R represents an aliphatic diol residue having 2 to 6 carbon atoms. It has the repeating unit represented by these. However, in the repeating unit represented by the general formula (III), R may be an aliphatic diol residue having a different carbon number for each repeating unit, that is, an alkylene group.
- the aliphatic polycarbonate diol used is represented by the general formula (IIIa) and the general formula (IIIb).
- Ra and Rb both represent an aliphatic diol residue having 2 to 6 carbon atoms, but have different carbon numbers from each other. It may also have a repeating unit represented by:
- Examples of the aliphatic diol residue having 2 to 6 carbon atoms include, for example, ethylene glycol, 1,3-trimethylene diol, 1,4-tetramethylene diol, 1,5-pentamethylene diol, neodymium, as described above.
- An aliphatic hydrocarbon group in an aliphatic diol such as pentyl glycol, 1,6-hexamethylene diol, 1,4-cyclohexane diol, etc., preferably a linear or branched alkylene group.
- polyfunctional isocyanates include phenylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, diphenyl ether diisocyanate, hexamethylene diisocyanate, cyclohexane diisocyanate, and other aromatic, araliphatic, alicyclic, and aliphatic diisocyanates, and trimethylolpropane. So-called isocyanate adducts obtained by adding these diisocyanates to polyols such as are also used.
- the reactive polymer by reacting the reactive polymer with the urethane prepolymer, the reactive polymer is crosslinked with the prepolymer to obtain a crosslinked polymer having a polycarbonate urethane skeleton.
- the battery separator according to the present invention is obtained by supporting such a crosslinked polymer layer on the porous substrate. That is, the battery separator according to the present invention includes a porous substrate and a layer of the crosslinked polymer supported on the porous substrate.
- the cross-linked polymer layer may be supported on at least one surface of the porous base material depending on the intended function of the battery separator.
- the continuous layer it can be supported in various modes.
- the reactive polymer and the urethane prepolymer are dissolved in an appropriate solvent such as acetone, ethyl acetate, butyl acetate, toluene, and the obtained solution is used as the porous substrate.
- an appropriate solvent such as acetone, ethyl acetate, butyl acetate, toluene
- the obtained solution is used as the porous substrate.
- a thin layer containing the mixture of the reactive polymer and the urethane prepolymer is formed on the release sheet.
- This peelable sheet is layered on a porous substrate and heated and pressed to transfer a thin layer composed of a mixture of the reactive polymer and urethane prepolymer onto the porous substrate, and then the reaction on the porous substrate.
- a thin layer made of a mixture of a functional polymer and a urethane prepolymer may be heated to cause the reactive polymer to react with the urethane prepolymer for crosslinking.
- heating may be performed at 90 ° C. for 48 hours.
- a solution containing a reactive polymer and a urethane prepolymer is prepared, and this is heated, so that the crosslinked polymer to be generated is not phase-separated in the solution in advance.
- a solution is applied to a porous substrate or a peelable sheet, heated to remove the solvent, and further heated to react.
- the polymer may be reacted with a urethane prepolymer to crosslink.
- a polypropylene resin sheet is typically preferably used, but is not limited thereto.
- the ratio of the reactive polymer to the urethane prepolymer used is the ratio of the reactive group in the reactive polymer.
- the amount of the isocyanate group in the urethane prepolymer and the molecular weight of the reactive polymer and the urethane prepolymer depend on the properties such as the molecular weight of the reactive polymer and the urethane prepolymer. Part range.
- the ratio of the urethane prepolymer to 100 parts by weight of the reactive polymer is less than 10 parts by weight, the resulting crosslinked polymer does not have satisfactory oxidation resistance.
- the ratio of the urethane prepolymer to 100 parts by weight of the reactive polymer is more than 150 parts by weight, the crosslinking density of the obtained crosslinked polymer is too high, and a porous substrate carrying such a crosslinked polymer is used as a battery. Even if it is used in the production of the battery, a battery having excellent characteristics cannot be obtained.
- the amount of the reactive polymer and the urethane prepolymer supported on the porous substrate is determined depending on the type of the reactive polymer and the urethane prepolymer used, and those supported on the porous substrate. Although it depends on the embodiment to be used, it is usually in the range of 0.2 to 5.0 g / m 2 , and preferably in the range of 0.3 to 3.0 g / m 2 .
- the amount of the crosslinked polymer supported on the porous substrate is too small, the obtained separator does not have sufficient adhesion to the electrode. On the other hand, when the amount is too large, the battery using the obtained separator is deteriorated in characteristics, which is not preferable.
- the cross-linked polymer obtained by reaction of the reactive polymer with the urethane prepolymer is in the range of 50 to 99% by weight, preferably 60 to 99% by weight, more preferably 70 to 99% by weight.
- the insoluble fraction refers to the ratio of the crosslinked polymer remaining on the porous substrate after the porous substrate carrying the crosslinked polymer is immersed in ethyl acetate at room temperature for 6 hours with stirring.
- the electrode / separator laminate can be obtained by temporarily adhering the electrodes to the separator and bonding them together.
- the electrode that is, the negative electrode and the positive electrode differ depending on the battery, but in general, a sheet in which an active material and, if necessary, a conductive agent are supported on a conductive base material using a resin binder.
- the shape is used.
- the electrode / separator laminate may have electrodes laminated on the separator. Therefore, for example, a negative electrode / separator / positive electrode, a negative electrode / separator / positive electrode / separator, or the like is used as the electrode / separator laminate according to the structure or form of the battery.
- the electrode / separator laminate may be in the form of a sheet or may be wound.
- the electrode is laminated on the separator or wound and temporarily bonded to obtain an electrode / separator laminate, and then this laminate is charged into a battery container made of a metal tube, a laminate film, etc.
- a predetermined amount of non-aqueous electrolyte is injected into the battery container, the battery container is sealed and sealed, and the crosslinked polymer supported on the separator is used as an electrode.
- Porous with a cross-linked polymer by swelling at least a part with an electrolyte near the interface of the electrode and allowing it to penetrate into the gap between the electrode active materials to develop an anchor effect on both the porous substrate and the electrode.
- An electrode / separator assembly in which an electrode is bonded to a porous substrate can be obtained, and thus a battery having an electrode / separator assembly can be obtained.
- the crosslinked polymer supported on the porous substrate has a high insoluble content as described above, the electrolyte solution can be used even when immersed in the electrolyte solution during battery production. Elution and diffusion into the inside are suppressed. Therefore, in the production of the battery, the crosslinked polymer is hardly eluted into the electrolyte solution and the battery characteristics are hardly deteriorated.
- the wettability of the electrode to the electrolytic solution is dramatically improved by the initial charge / discharge.
- the crosslinked polymer swollen by the electrolytic solution further penetrates into the gaps between the electrode active materials, thereby further strengthening the adhesion between the separator and the electrode.
- the electrode / separator laminate is charged into the battery container, and after the electrolyte solution is injected into the battery container, the crosslinked polymer and the electrode supported on the porous base material are further heated by heating. It can be adhered.
- the heating condition depends on the heat resistance and productivity of the material constituting the battery, but it is usually set at a temperature of 40 to 100 ° C. for about 0.5 to 24 hours.
- the crosslinked polymer functions as an adhesive for bonding the electrode to the separator, and is useful for forming an electrode / separator assembly.
- the electrode / separator assembly in the battery, it is possible to prevent the electrode from being separated from the separator to expose the electrode, or the separator to contract and the electrode from being exposed.
- the separator in the battery obtained, is adhered to the electrode, so that, for example, even when the battery is placed in a high temperature environment such as 150 ° C., the separator (strictly, porous The base material) has a small area heat shrinkage rate, usually 20% or less, and preferably 15% or less.
- the mode in which the layer of the crosslinked polymer is supported on the porous substrate is not particularly limited. Therefore, the cross-linked polymer layer may be supported on the entire surface of the porous substrate, and in some cases, for example, streaks, spots, lattices, stripes, turtle shells Alternatively, a cross-linked polymer layer may be partially supported in a shape or the like. Further, the crosslinkable polymer layer may be supported only on one surface of the porous substrate, or may be supported on both surfaces.
- the crosslinked polymer has a crosslinked structure formed by crosslinking a reactive polymer using a urethane prepolymer as a crosslinking agent, and has a polycarbonate skeleton. Have sex. Therefore, the separator according to the present invention is useful because it has a function of imparting high oxidation resistance to the porous substrate constituting the separator.
- the separator substrate is a porous film of a polyolefin resin such as polyethylene or polypropylene, as described above, when the charging voltage is increased, the positive electrode active material has a high oxidation state and a high oxidation reaction. Therefore, the separator is easily damaged and deteriorated.
- a separator made of a polyolefin resin porous film carrying the cross-linked polymer layer is formed.
- the separator can have excellent oxidation resistance, and thus a battery having high energy density and excellent charge / discharge characteristics can be obtained.
- the non-aqueous electrolyte is a solution obtained by dissolving an electrolyte salt in an appropriate organic solvent.
- the electrolyte salt include alkali metals such as hydrogen, lithium, sodium, and potassium, alkaline earth metals such as calcium and strontium, tertiary or quaternary ammonium salts, and the like as cationic components, hydrochloric acid, nitric acid, phosphoric acid, sulfuric acid A salt containing an anionic component of an inorganic acid such as borohydrofluoric acid, hydrofluoric acid, hexafluorophosphoric acid or perchloric acid, or an organic acid such as carboxylic acid, organic sulfonic acid or fluorine-substituted organic sulfonic acid. it can.
- an electrolyte salt containing an alkali metal ion as a cation component is particularly preferably used.
- electrolyte salt having such an alkali metal ion as a cation component include, for example, alkali perchlorate such as lithium perchlorate, sodium perchlorate, potassium perchlorate, lithium tetrafluoroborate, tetra Alkali metal tetrafluoroborate such as sodium fluoroborate and potassium tetrafluoroborate, alkali metal hexafluorophosphate such as lithium hexafluorophosphate and potassium hexafluorophosphate, alkali trifluoroacetate such as lithium trifluoroacetate Mention may be made of metals and alkali metals of trifluoromethane sulfonate such as lithium trifluoromethane sulfonate.
- lithium hexafluorophosphate lithium tetrafluoroborate, lithium perchlorate or the like is preferably used.
- any solvent can be used as long as it dissolves the electrolyte salt.
- the non-aqueous solvent include ethylene carbonate, propylene carbonate, Use cyclic esters such as butylene carbonate and ⁇ -butyrolactone, ethers such as tetrahydrofuran and dimethoxyethane, and chain esters such as dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate alone or as a mixture of two or more. be able to.
- Reference example 1 (Preparation of electrode sheet) 85 parts by weight of lithium cobaltate (cell chemical C-10 manufactured by Nippon Chemical Industry Co., Ltd.) as a positive electrode active material and 10 parts by weight of acetylene black (Denka Black manufactured by Denki Kagaku Kogyo Co., Ltd.) as a conductive auxiliary agent and a binder. 5 parts by weight of vinylidene fluoride resin (KF Polymer L # 1120 manufactured by Kureha Chemical Industry Co., Ltd.) was mixed, and this was mixed with a slurry using N-methyl-2-pyrrolidone so as to have a solid concentration of 15% by weight. did.
- lithium cobaltate cell chemical C-10 manufactured by Nippon Chemical Industry Co., Ltd.
- acetylene black Denki Kagaku Kogyo Co., Ltd.
- vinylidene fluoride resin KF Polymer L # 1120 manufactured by Kureha Chemical Industry Co., Ltd.
- the slurry was applied to an aluminum foil (current collector) having a thickness of 20 ⁇ m to a thickness of 200 ⁇ m, vacuum-dried at 80 ° C. for 1 hour, and 120 ° C. for 2 hours, and then pressed by a roll press to obtain a thickness of the active material layer.
- a positive electrode sheet having a thickness of 100 ⁇ m was prepared.
- mesocarbon microbeads (MCMB6-28 manufactured by Osaka Gas Chemical Co., Ltd.) as a negative electrode active material
- a binder 10 parts by weight of vinylidene fluoride resin KF Polymer L # 1120 manufactured by Kureha Chemical Industry Co., Ltd.
- N-methyl-2-pyrrolidone so as to have a solid concentration of 15% by weight
- This slurry was applied onto a copper foil (current collector) having a thickness of 20 ⁇ m, applied to a thickness of 200 ⁇ m, dried at 80 ° C. for 1 hour, dried at 120 ° C. for 2 hours, and then pressed with a roll press, A negative electrode sheet having an active material layer thickness of 100 ⁇ m was prepared.
- Coat hanger 15 parts by weight of ultra-high molecular weight polyethylene (melting point: 137 ° C.) with a weight average molecular weight of 1 million and 85 parts by weight of liquid paraffin are mixed uniformly in a slurry, and melt kneaded at a temperature of 170 ° C. with a twin screw extruder. Extruded into a 2 mm thick sheet with a die. The obtained sheet was cooled while taking a roll to obtain a gel sheet having a thickness of 1.3 mm. This gel sheet was simultaneously biaxially stretched 4.5 ⁇ 5 times in the MD direction (machine direction) and the TD direction (width direction) at a temperature of 123 ° C. to obtain a stretched film.
- the decane After removing liquid paraffin from the stretched film using decane, the decane was dried at room temperature to obtain a porous film.
- the obtained porous film was heat-treated in air at a temperature of 125 ° C. for 3 minutes to obtain a polyethylene resin porous film.
- the obtained porous film had a thickness of 16 ⁇ m, a porosity of 39%, an air permeability of 270 seconds / 100 cc, and a puncture strength of 4N.
- Comparative Example 1 The negative electrode sheet obtained in Reference Example 1, the polyethylene resin porous film obtained in Reference Example 2 and the positive electrode sheet obtained in Reference Example 1 were laminated in this order to form an electrode / porous film laminate.
- the obtained battery was charged and discharged twice at room temperature with a current of 0.2 CmA, and then subjected to an evaluation test for the following three battery characteristics. However, separate batteries were used for the following three battery property evaluation tests.
- Rate characteristic (%) 2 CmA discharge capacity B / 0.2 CmA discharge capacity A
- the battery whose rate characteristics were evaluated was subjected to the following area shrinkage measurement of the porous substrate.
- the test structure is obtained by sandwiching a battery whose rate characteristic, which is an evaluation item of the battery characteristics described above, between a pair of glass plates, and fixing both ends of the pair of glass plates with a polyimide tape so that the distance therebetween is not widened. Assembled.
- This test structure was put into a dryer at 150 ° C. for 1 hour, allowed to cool, and then the test structure was disassembled, and the resulting electrode / crosslinked polymer-supported porous substrate assembly was used as a porous substrate. Then, this was read with a scanner, and compared with the area of the porous substrate before the test, the area shrinkage ratio of the porous substrate was determined.
- the battery was continuously charged at a constant current and a constant voltage at a room temperature of a current of 0.2 CmA and a voltage of 4.2 V for 12 hours. Next, in this fully charged state, the battery voltage was measured at a temperature of 80 ° C. after being kept in a constant temperature bath at 80 ° C. for 4 days.
- Table 1 shows the rate characteristics of the battery, the continuous charge characteristics, and the results of the high-temperature storage test, along with the area shrinkage ratio of the porous substrate in the battery.
- Reference example 3 (Preparation of reactive polymer) In a 500 mL three-necked flask equipped with a reflux condenser, 84 g of methyl methacrylate, 2.0 g of 4-hydroxybutyl acrylate, 14.0 g of 2-methoxyethyl acrylate, 25 g of ethyl acetate and N, N′-azobisisobutyro Nitrile 0.20 g was charged and stirred and mixed for 30 minutes while introducing nitrogen gas, and then heated to 70 ° C. to initiate radical polymerization. When about 1 hour had elapsed, an increase in the viscosity of the reaction mixture was observed. Thereafter, while adding ethyl acetate to the reaction mixture, the temperature was kept substantially constant, and the polymerization was further continued for 8 hours.
- reaction mixture was cooled to 40 ° C., ethyl acetate was added, and the mixture was stirred and mixed until the whole became uniform to obtain an ethyl acetate solution (concentration 15% by weight) of the reactive polymer.
- Comparative Example 2 10 g of the reactive polymer obtained in Reference Example 3 was dissolved in ethyl acetate at room temperature to prepare a 10% by weight reactive polymer solution. To this, 3.14 g of polyfunctional isocyanate (hexamethylene diisocyanate / trimethylolpropane adduct, ethyl acetate solution, solid content 25%, Coronate HL manufactured by Nippon Polyurethane Industry Co., Ltd.) was added and dissolved to dissolve the reactive polymer and polyfunctional isocyanate. A coating solution containing a functional isocyanate was prepared.
- polyfunctional isocyanate hexamethylene diisocyanate / trimethylolpropane adduct, ethyl acetate solution, solid content 25%, Coronate HL manufactured by Nippon Polyurethane Industry Co., Ltd.
- the mixture After applying this coating solution on one side of a polypropylene resin sheet using a wire bar, the mixture is heated at 50 ° C. for 5 minutes to volatilize ethyl acetate, and a thin layer composed of a mixture of a reactive polymer and a polyfunctional isocyanate is formed into a propylene resin. Formed on a sheet.
- This polypropylene resin sheet was laminated so that a thin layer composed of a mixture of a reactive polymer and a polyfunctional isocyanate was in contact with the polyethylene resin porous film obtained in Reference Example 2, and this was heated to a temperature of 125 ° C.
- a thin layer made of a mixture of a reactive polymer and a polyfunctional isocyanate was transferred to one side of a polyethylene resin porous film by heating and pressing through a laminating roll.
- a laminate composed of the polyethylene resin porous film having the thin layer and the polypropylene resin sheet is heated at 90 ° C. for 48 hours, the reactive polymer and the polyfunctional isocyanate are reacted, the reactive polymer is crosslinked, and the crosslinking is performed.
- the polypropylene resin sheet was peeled off to obtain a polyethylene resin porous film having a crosslinked polymer supported on one side.
- the amount of the crosslinked polymer supported on the polyethylene resin porous film was 0.5 g / m 2 .
- the weight of the crosslinked polymer on the polyethylene resin porous film is regarded as the weight of a thin layer composed of a mixture of the reactive polymer and the polyfunctional isocyanate formed on the polypropylene resin sheet, and the polyethylene resin porous film
- the amount of the crosslinked polymer supported on the film was determined as follows. That is, a polypropylene resin sheet having a thin layer made of a mixture of the reactive polymer and polyfunctional isocyanate was cut into a size of 5 cm ⁇ 2 cm, and its weight A was measured.
- the weight B of the polypropylene resin sheet is measured to support the crosslinked polymer on the polyethylene resin porous film. The amount was calculated from (AB) ⁇ 1000 (g / m 2 ).
- the negative electrode sheet obtained in Reference Example 1, the polyethylene resin porous film carrying the crosslinked polymer, and the positive electrode sheet obtained in Reference Example 1 were arranged in this order so that the crosslinked polymer on the porous film faced the positive electrode sheet.
- the package was sealed. Thereafter, the battery was charged with a current of 0.2 CmA until reaching 3.5 V, and then charged in a thermostat at 50 ° C. for 24 hours to promote adhesion between the electrode sheet and the separator, thereby obtaining a laminate seal type battery.
- Reference example 4 (Preparation of reactive polymer) A 500 mL three-necked flask equipped with a reflux condenser was charged with 98 g of methyl methacrylate, 2.0 g of 4-hydroxybutyl acrylate, 25 g of ethyl acetate and 0.20 g of N, N′-azobisisobutyronitrile, and nitrogen gas. Then, the mixture was stirred and mixed for 30 minutes and then heated to 70 ° C. to initiate radical polymerization. After about 2 hours, an increase in the viscosity of the reaction mixture was observed, and then the temperature was kept substantially constant while adding ethyl acetate, and the polymerization was continued for another 8 hours.
- reaction mixture was cooled to 40 ° C., ethyl acetate was added, and the mixture was heated and stirred until the whole became uniform to obtain a reactive polymer solution (concentration 25% by weight).
- Example 1 6 g of the reactive polymer obtained in Reference Example 4 was dissolved in toluene at room temperature to prepare 50 g of a reactive polymer solution having a concentration of 12% by weight, and this and a terminal isocyanate group having a concentration of 12% by weight obtained in Reference Example 4 were obtained. 22.5 g of a toluene solution of polycarbonate urethane prepolymer was mixed and stirred. Furthermore, 145 g of toluene was added to the obtained mixed solution to prepare a coating solution having a solid content concentration of 4% by weight.
- This coating solution is applied to one side of a polypropylene resin sheet using a spin coater, heated at 50 ° C. for 1 hour to evaporate toluene, and a thin layer made of a mixture of a reactive polymer and the urethane prepolymer is formed into a polypropylene resin. Formed on a sheet.
- This polypropylene resin sheet was laminated so that a thin layer made of a mixture of a reactive polymer and a urethane prepolymer was in contact with the polyethylene resin porous film obtained in Reference Example 2, and this was heated to a temperature of 125 ° C.
- a thin layer made of a mixture of a reactive polymer and a urethane prepolymer was transferred to one side of a polyethylene resin porous film by heating and pressing through a laminating roll.
- a laminate composed of the polyethylene resin porous film having the thin layer and the polypropylene resin sheet is heated at 90 ° C. for 48 hours to react the reactive polymer with the urethane prepolymer, to crosslink the reactive polymer, and to insolubilize. After 99% of the crosslinked polymer was obtained, the polypropylene resin sheet was peeled off to obtain a polyethylene resin porous film having the crosslinked polymer supported on one surface at a supported amount of 0.5 g / m 2 .
- the negative electrode sheet obtained in Reference Example 1, the polyethylene resin porous film carrying the crosslinked polymer, and the positive electrode sheet obtained in Reference Example 1 were arranged in this order so that the crosslinked polymer on the porous film faced the positive electrode sheet.
- the package was sealed.
- the battery was charged with a current of 0.2 CmA until reaching 3.5 V, and then charged in a thermostat at 50 ° C. for 24 hours to promote the adhesion between the electrode sheet and the polyethylene resin porous film, and the laminate seal type battery was Obtained.
- Reference Example 5 (Preparation of reactive polymer) A 500 mL three-necked flask equipped with a reflux condenser was charged with 98 g of methyl methacrylate, 2.0 g of 4-hydroxybutyl acrylate, 25 g of ethyl acetate and 0.20 g of N, N′-azobisisobutyronitrile, and nitrogen gas. Then, the mixture was stirred and mixed for 30 minutes and then heated to 70 ° C. to initiate radical polymerization. After about 2 hours, an increase in the viscosity of the reaction mixture was observed, and then the temperature was kept substantially constant while adding ethyl acetate, and the polymerization was continued for 8 hours.
- reaction mixture was cooled to 40 ° C., ethyl acetate was added, and the mixture was stirred and mixed until the whole became uniform to obtain a reactive polymer solution (concentration 25% by weight).
- Example 2 6 g of the reactive polymer obtained in Reference Example 5 was dissolved in ethyl acetate at room temperature to prepare 50 g of a reactive polymer solution having a concentration of 12% by weight. To this, a urethane prepolymer having a concentration of 12% by weight obtained in Reference Example 5 was added. 16 g of an ethyl acetate solution of the polymer was added, and the mixture was heated to 80 ° C. with stirring and reacted for 20 hours. Thereafter, the reaction mixture was cooled, and 132 g of ethyl acetate was added thereto to prepare a coating solution having a solid content concentration of 4% by weight.
- the mixture After applying this coating solution to one side of a polypropylene resin sheet using a spin coater, the mixture is heated at 50 ° C. for 5 minutes to volatilize ethyl acetate, and a thin layer made of a mixture of a reactive polymer and a urethane prepolymer is formed into a polypropylene resin. Formed on a sheet.
- This polypropylene resin sheet was laminated so that a thin layer made of a mixture of a reactive polymer and a urethane prepolymer was in contact with the polyethylene resin porous film obtained in Reference Example 2, and this was heated to a temperature of 125 ° C.
- a thin layer made of a mixture of a reactive polymer and a urethane prepolymer was transferred to one side of a polyethylene resin porous film by heating and pressing through a laminating roll.
- a laminate composed of the polyethylene resin porous film having the thin layer and the polypropylene resin sheet is heated at 90 ° C. for 48 hours to react the reactive polymer with the urethane prepolymer, to crosslink the reactive polymer, and to insolubilize.
- the polypropylene resin sheet was peeled off to obtain a polyethylene resin porous film carrying the cross-linked polymer on one side at a carrying amount of 0.5 g / m 2 .
- the negative electrode sheet obtained in Reference Example 1, the polyethylene resin porous film carrying the crosslinked polymer, and the positive electrode sheet obtained in Reference Example 1 were arranged in this order so that the crosslinked polymer on the porous film faced the positive electrode sheet.
- the package was sealed.
- the battery was charged with a current of 0.2 CmA until reaching 3.5 V, and then charged in a thermostat at 50 ° C. for 24 hours to promote the adhesion between the electrode sheet and the polyethylene resin porous film, and the laminate seal type battery was Obtained.
- the obtained battery it carried out similarly to the comparative example 1, and shows the result of the rate characteristic of a battery, a continuous charge characteristic, and a high temperature storage test with the area shrinkage rate of a porous base material (polyethylene resin porous film). .
- Example 3 6.0 g of the reactive polymer obtained in Reference Example 5 was dissolved in ethyl acetate at room temperature to prepare 50 g of a reactive polymer solution having a concentration of 12% by weight. 60 g of an ethyl acetate solution of a urethane prepolymer was added, heated to 80 ° C. with stirring, and reacted for 20 hours. After the obtained reaction mixture was cooled, 220 g of ethyl acetate was added thereto to prepare a coating solution having a solid content concentration of 4% by weight.
- This coating solution is applied to one side of a polypropylene resin sheet using a spin coater, and then heated at 50 ° C. for 5 minutes to volatilize ethyl acetate. From the reaction product and the reaction product together with the reactive polymer and the urethane prepolymer. A thin layer was formed on a polypropylene resin sheet.
- the polypropylene resin sheet was laminated so that the thin layer was in contact with the polyethylene resin porous film obtained in Reference Example 2 to form a laminate, and this was heated and pressurized through a laminating roll heated to a temperature of 125 ° C. The thin layer was transferred to one side of a polyethylene resin porous film.
- a laminate composed of the polyethylene resin porous film having the thin layer and the polypropylene resin sheet is heated at 90 ° C. for 48 hours to react the reactive polymer with the urethane prepolymer, to crosslink the reactive polymer, and to insolubilize.
- the polypropylene resin sheet was peeled off to obtain a polyethylene resin porous film carrying the cross-linked polymer on one side at a carrying amount of 0.5 g / m 2 .
- the negative electrode sheet obtained in Reference Example 1, the polyethylene resin porous film carrying the crosslinked polymer, and the positive electrode sheet obtained in Reference Example 1 were arranged in this order so that the crosslinked polymer on the porous film faced the positive electrode sheet.
- the package was sealed. Thereafter, the battery is charged with a current of 0.2 CmA until reaching 3.5 V, and then charged into a thermostat at 50 ° C. for 24 hours to promote the adhesion between the electrode sheet and the polyethylene resin porous film, thereby obtaining a laminated seal type battery. It was.
- the obtained battery it carried out similarly to the comparative example 1, and shows the result of the rate characteristic of a battery, a continuous charge characteristic, and a high temperature storage test with the area shrinkage rate of a porous base material (polyethylene resin porous film). .
- reaction mixture was cooled to 40 ° C., ethyl acetate was added, and the mixture was stirred and mixed until the whole became uniform to obtain a reactive polymer solution (concentration 25% by weight).
- Example 4 9 g of the reactive polymer obtained in Reference Example 6 was dissolved in toluene at room temperature to prepare 90 g of a reactive polymer solution having a concentration of 10% by weight, and 32.4 g of a urethane prepolymer solution having a concentration of 12.5% by weight. Mixed and stirred. Furthermore, 95.1 g of toluene was added to the obtained mixed solution to prepare a coating solution having a solid concentration of 6% by weight.
- this coating solution After applying this coating solution on one side of a polypropylene resin sheet using a spin coater, it is heated at 50 ° C. for 5 minutes to volatilize toluene, and a thin layer made of a mixture of a reactive polymer and a urethane prepolymer is formed into a polypropylene resin sheet. Formed on top.
- This polypropylene resin sheet was laminated so that a thin layer made of a mixture of a reactive polymer and a urethane prepolymer was in contact with the polyethylene resin porous film obtained in Reference Example 2, and this was heated to a temperature of 125 ° C.
- a thin layer made of a mixture of a reactive polymer and a urethane prepolymer was transferred to one side of a polyethylene resin porous film by heating and pressing through a laminating roll.
- a laminate composed of the polyethylene resin porous film having the thin layer and the polypropylene resin sheet is heated at 90 ° C. for 48 hours to react the reactive polymer with the urethane prepolymer, to crosslink the reactive polymer, and to insolubilize.
- the polypropylene resin sheet was peeled off to obtain a polyethylene resin porous film carrying the crosslinked polymer on one side at a loading amount of 0.5 g / m 2 .
- the negative electrode sheet obtained in Reference Example 1, the polyethylene resin porous film supporting the crosslinked polymer, and the positive electrode sheet obtained in Reference Example 1 were arranged in this order so that the crosslinked polymer on the porous film faced the positive electrode sheet.
- the package was sealed.
- the battery was charged with a current of 0.2 CmA until reaching 3.5 V, and then charged in a thermostat at 50 ° C. for 24 hours to promote the adhesion between the electrode sheet and the polyethylene resin porous film, and the laminate seal type battery was Obtained.
- the obtained battery it carried out similarly to the comparative example 1, and shows the result of the rate characteristic of a battery, a continuous charge characteristic, and a high temperature storage test with the area shrinkage rate of a porous base material (polyethylene resin porous film). .
- Reference Example 7 (Preparation of reactive polymer) A 500 mL three-necked flask equipped with a reflux condenser was charged with 98 g of methyl methacrylate, 2.0 g of 4-hydroxybutyl acrylate, 25 g of ethyl acetate and 0.20 g of N, N′-azobisisobutyronitrile, and nitrogen gas. Then, the mixture was stirred and mixed for 30 minutes and then heated to 70 ° C. to initiate radical polymerization. After about 2 hours, an increase in the viscosity of the reaction mixture was observed, and then the temperature was kept substantially constant while adding ethyl acetate, and the polymerization was continued for 8 hours.
- reaction mixture was cooled to 40 ° C., ethyl acetate was added, and the mixture was stirred and mixed until the whole became uniform to obtain a reactive polymer solution (concentration 25% by weight).
- Example 5 6 g of the reactive polymer obtained in Reference Example 7 was dissolved in toluene at room temperature to prepare 60 g of a 10% by weight reactive polymer solution, and this was mixed with 48 g of a 12.5% by weight urethane prepolymer solution. , Stirred. Furthermore, 92 g of toluene was added to the obtained mixed solution to prepare a coating solution having a solid concentration of 6% by weight.
- this coating solution After applying this coating solution on one side of a polypropylene resin sheet using a spin coater, it is heated at 50 ° C. for 5 minutes to volatilize toluene, and a thin layer made of a mixture of a reactive polymer and a urethane prepolymer is formed into a polypropylene resin sheet. Formed on top.
- This polypropylene resin sheet was laminated so that a thin layer made of a mixture of a reactive polymer and a urethane prepolymer was in contact with the polyethylene resin porous film obtained in Reference Example 2, and this was heated to a temperature of 125 ° C.
- a thin layer made of a mixture of a reactive polymer and a urethane prepolymer was transferred to one side of a polyethylene resin porous film by heating and pressing through a laminating roll.
- a laminate composed of the polyethylene resin porous film having the thin layer and the polypropylene resin sheet is heated at 90 ° C. for 48 hours to react the reactive polymer with the urethane prepolymer, to crosslink the reactive polymer, and to insolubilize.
- the polypropylene resin sheet was peeled off to obtain a polyethylene resin porous film carrying the crosslinked polymer on one side at a loading amount of 0.5 g / m 2 .
- the negative electrode sheet obtained in Reference Example 1, the polyethylene resin porous film supporting the crosslinked polymer, and the positive electrode sheet obtained in Reference Example 1 were arranged in this order so that the crosslinked polymer on the porous film faced the positive electrode sheet.
- the package was sealed.
- the battery was charged with a current of 0.2 CmA until reaching 3.5 V, and then charged in a thermostat at 50 ° C. for 24 hours to promote the adhesion between the electrode sheet and the polyethylene resin porous film, and the laminate seal type battery was Obtained.
- the obtained battery it carried out similarly to the comparative example 1, and shows the result of the rate characteristic of a battery, a continuous charge characteristic, and a high temperature storage test with the area shrinkage rate of a porous base material (polyethylene resin porous film). .
- Reference example 1 A polytetrafluoroethylene resin porous film having a porosity of 97% and a thickness of 5 ⁇ m was laminated on one side of the polyethylene resin porous film obtained in Reference Example 2 and supported.
- the negative electrode sheet obtained in Reference Example 1, the polytetrafluoroethylene resin porous film-carrying polyethylene resin porous film, and the positive electrode sheet obtained in Reference Example 1 on the polyethylene resin porous film. are laminated in this order so as to face the positive electrode sheet to form an electrode / fluororesin porous film-supported polyethylene resin porous film laminate, which is charged into an aluminum laminate package, and has a concentration of 1.4 mol / L.
- an electrolytic solution composed of a mixed solvent of ethylene carbonate / diethyl carbonate (weight ratio 1/1) in which lithium hexafluorophosphate was dissolved
- the package was sealed. Thereafter, the battery was charged with a current of 0.20 CmA until reaching 3.5 V to obtain a laminate seal type battery.
- the battery thus obtained was evaluated for continuous charge characteristics and high-temperature storage characteristics in the same manner as in Comparative Example 1. As shown in Table 1, no increase in current value was observed during continuous charging. Moreover, the voltage after high temperature storage was 4.1V.
- the crosslinked polymer having a polycarbonate urethane skeleton provided between the positive electrode and the separator does not undergo oxidative deterioration despite the high oxidation reactivity of the positive electrode.
- the crosslinked polymer functions as a protective layer for the separator, oxidation degradation of the separator can be prevented even when a polyolefin resin porous film is used as the separator.
- a battery separator having excellent oxidation resistance and adhesion to the electrode is obtained. Further, according to the present invention, a battery using such a battery separator is provided.
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Electrochemistry (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Inorganic Chemistry (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Dispersion Chemistry (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Secondary Cells (AREA)
- Cell Separators (AREA)
Abstract
Description
(1)多孔質基材、および
前記多孔質基材の少なくとも1つの表面に担持された架橋ポリマーの層
を含む電池用セパレータであって、
前記架橋ポリマーが、
(a)分子中に活性水素を含む反応性基を有する反応性ポリマーと、
(b)末端イソシアネート基ポリカーボネートウレタンプレポリマー
との反応によって得られる電池用セパレータ。
(2)活性水素を含む反応性基が、ヒドロキシ基、カルボキシル基及びアミノ基から選ばれる少なくとも1種である(1)に記載の電池用セパレータ。
(3)多孔質基材がポリオレフィン樹脂多孔質フィルムである(1)に記載の電池用セパレータ。
(4)ポリオレフィン樹脂多孔質フィルムがポリエチレン樹脂多孔質フィルムである(3)に記載の電池用セパレータ。
(5)(1)から(4)のいずれかに記載のセパレータ、および
前記セパレータを挟んで積層された正極と負極
を含む電極/セパレータ接合体であって、
架橋ポリマーによって正極と負極の少なくとも一方が多孔質基材に接着されている電極/セパレータ接合体。
(6)(5)に記載の電極/セパレータ接合体を有する電池。
(7)さらに非水電解液を含み、架橋ポリマーの層が少なくとも正極に対面している(6)に記載の電池。
(8)(1)から(4)のいずれかに記載のセパレータを挟んで正極と負極を積層すること、
得られた積層体を電池容器内に仕込んだ後、非水電解液を上記電池容器内に注入すること、および
架橋ポリマーによって正極と負極の少なくとも一方が多孔質基材に接着されてなる電極/セパレータ接合体を形成すること
を含む電池の製造方法。
(9)架橋ポリマーの層が少なくとも正極に対面するようにセパレータを挟んで正極と負極を積層する(8)に記載の電池の製造方法。
本発明において、多孔質基材は、厚み3~50μmの範囲のものが好ましく用いられる。多孔質基材の厚みが3μmよりも薄いときは、強度が不十分であって、電池においてセパレータとして用いるとき、電極が内部短絡を起こすおそれがある。他方、多孔質基材の厚みが50μmを越えるときは、そのような多孔質基材をセパレータとして用いる電池は電極間距離が大きすぎて、電池の内部抵抗が過大となる。
の範囲のものが用いられ、好ましくは、30~90%、最も好ましくは、35~85%の範囲のものが用いられる。空孔率が余りに低いときは、電池のセパレータとして用いた場合に、イオン伝導経路が少なくなり、十分な電池特性を得ることができない。他方、空孔率が余りに高いときは、電池のセパレータとして用いた場合に、強度が不十分であり、所要の強度を得るためには、多孔質基材として厚いものを用いなければならない。そのため、電池の内部抵抗が高くなるので好ましくない。
本発明において、反応性ポリマーは、分子中に活性水素を含む反応性基を有するポリマーをいい、活性水素を含む反応性基とは、活性水素によってイソシアネート基と反応性を有する基をいい、そのような反応性基として、例えば、ヒドロキシ基、カルボキシル基及びアミノ基から選ばれる少なくとも1種を挙げることができる。
で表される(メタ)アクリレートや、一般式(II)
で表されるビニルエステルを挙げることができる。
等を挙げることができる。
本発明において、末端イソシアネート基ポリカーボネートウレタンプレポリマー(以下、単に、ウレタンプレポリマーという。)は、好ましくは、脂肪族ポリカーボネートジオールと多官能イソシアネートを、多官能イソシアネートの有するイソシアネート基/ポリカーボネートジオールの有するヒドロキシ基のモル比(以下、NCO/OHモル比という。)を、通常、1.2~3.3の範囲、好ましくは、1.5~2.5の範囲にて反応させることによって得られるオリゴマーである。上記NCO/OHモル比によって、得られるウレタンプレポリマーの分子量が変化するが、NCO/OHモル比を上記範囲とするとき、分子の両末端が実質的にイソシアネート基であるウレタンプレポリマーを得ることができる。
で表される繰り返し単位を有する。但し、上記一般式(III)で表される繰り返し単位において、Rは繰り返し単位ごとに炭素数が異なる脂肪族ジオール残基、即ち、アルキレン基であってもよい。
で表される繰り返し単位を有するものでもあってもよい。
本発明によれば、前記反応性ポリマーと上記ウレタンプレポリマーを反応させることによって、反応性ポリマーがこのプレポリマーによって架橋されて、ポリカーボネートウレタン骨格を有する架橋ポリマーを得ることができる。本発明による電池用セパレータは、前記多孔質基材にこのような架橋ポリマーの層を担持させてなるものである。即ち、本発明による電池用セパレータは、多孔質基材とこれに担持された上記架橋ポリマーの層を含む。
上述したようにして得られる本発明によるセパレータに電極を積層し、例えば、本発明によるセパレータを挟んで正極と負極を積層し、必要に応じて、これらを加熱下に加圧して、圧着し、かくして、電極をセパレータに仮接着し、貼り合わせることによって、電極/セパレータ積層体を得ることができる。
1/10000mmシックネスゲージによる測定と多孔質基材の断面の10000倍走査型電子頭微鏡写真に基づいて求めた。
多孔質基材の単位面積S(cm2)当たりの重量W(g)、平均厚みt(cm)及び多孔質基材を構成する樹脂の密度d(g/cm3)から下式にて算出した。
空孔率(%)=(1-(W/S/t/d))×100
JIS P 8117に準拠して求めた。
カトーテック(株)製圧縮試験磯KES-G5を用いて、多孔質基材の突き刺し試験を行った。測定により得られた荷重変位曲線から最大荷重を読みとり、突き刺し強度とした。針は直径1.0mm、先端の曲率半径0.5mmのものを用いて、2cm/秒の速度で行った。
既知の量Aの架橋ポリマーを担持した多孔質基材を秤量して、その重量Bを測定した。次に、この架橋ポリマー担持多孔質基材を酢酸エチルに室温で6時間浸漬した後、風乾した。その後、このように処理した架橋ポリマー担持多孔質基材を秤量して、その重量Cを測定した。架橋ポリマーの不溶分率は次式にて算出した。
不溶分率(%)=((A-(B-C))/A)×100
(電極シートの調製)
正極活物質であるコバルト酸リチウム(日本化学工業(株)製セルシードC-10)85重量部と導電助剤であるアセチレンブラック(電気化学工業(株)製デンカブラック)10重量部とバインダーであるフッ化ビニリデン樹脂(呉羽化学工業(株)製KFポリマーL#1120)5重量部を混合し、これを固形分濃度15重量%となるように、N-メチル-2-ピロリドンを用いてスラリーとした。このスラリーを厚み20μmのアルミニウム箔(集電体)上に厚み200μmに塗布し、80℃で1時間、120℃で2時間真空乾燥した後、ロールプレスにて加圧して、活物質層の厚みが100μmの正極シートを調製した。
(ポリエチレン樹脂多孔質フィルムの作製)
重量平均分子量100万の超高分子量ポリエチレン(融点137℃)15重量部と流動パラフィン85重量部をスラリー状に均一に混合し、170℃の温度で二軸押出機にて溶解混練し、コートハンガーダイスにて厚さ2mmのシートに押出した。得られたシートをロール引取しながら冷却して、厚さ1.3mmのゲルシートを得た。このゲルシートを温度123℃でMD方向(機械方向)とTD方向(幅方向)に4.5×5倍に同時二軸延伸して、延伸フィルムを得た。
前記参考例1で得た負極シート、前記参考例2で得たポリエチレン樹脂多孔質フィルム及び前記参考例1で得た正極シートをこの順序で積層して、電極/多孔質フィルム積層体とし、これをアルミニウムラミネートパッケージ内に仕込み、1.4モル/L濃度でヘキサフルオロリン酸リチウムを溶解させたエチレンカーボネート/ジエチルカーボネート(重量比1/1)混合溶媒からなる電解液を注入した後、パッケージを封口した。この後、0.2CmAの電流で3.5Vに達するまで充電して、ラミネートシール型電池を得た。
得られた電池について、室温で0.2CmAの電流で2回充放電を行なった後、この電池を下記の3項目の電池特性の評価試験に供した。但し、下記3項目の電池特性の評価試験には、それぞれ別個の電池を用いた。
電池を0.2CmAで充電し、続いて、0.2CmAで放電して、0.2CmA放電容量Aを求めた。続いて、0.2CmAで充電した後、2CmAで放電して、2CmA放電容量Bを求めた。次式に基づいて、レート特性を算出した。
レート特性(%)=2CmA放電容量B/0.2CmA放電容量A
上述した電池特性の評価項目であるレート特性を測定した電池を一対のガラス板の間に挟み、その間の距離が広がらないように上記一対のガラス板の両端をポリイミドテープにて固定して、試験構造物を組み立てた。この試験構造物を150℃の乾燥機に1時間投入した後、放冷し、次いで、試験構造物を分解して、得られた電極/架橋ポリマー担持多孔質基材接合体から多孔質基材を剥がし、これをスキャナーで読み込んで、試験前の多孔質基材の面積と比較して、多孔質基材の面積収縮率を求めた。
電池を温度60℃の恒温槽に入れ、電流0.2CmA、電圧4.25Vの定電流定電圧充電を行なった。0.2CmAの電流での充電において、電池電圧が4.25Vに達すると、電流値が減衰するが、このように、一旦、減少した電流値は、再度、上昇する現象が観測される。この現象は高電圧で活性の高い正極近傍で何らかの化学反応が起こっていることを示唆していると考えられるので、セパレータの耐酸化性を評価する指標として、上述した充電における電流挙動を7日間観測した。この観測において、電流値の上昇が観測された場合、試験の開始から上記電流値の上昇が観測されるまでの時間を計測し、7日間の観測において、上記電流値の増大が観測されなかった場合は「増大なし」とした。
電池を室温にて電流0.2CmA、電圧4.2Vの定電流定電圧充電を12時間続けて行なった。次いで、この満充電状態のまま、80℃の恒温槽中に4日間保持した後、温度80℃で電池電圧を測定した。
(反応性ポリマーの調製)
還流冷却管を備えた500mL容量の3つ口フラスコにメチルメタクリレート84g、4-ヒドロキシブチルアクリレート2.0g、2-メトキシエチルアクリレート14.0g、酢酸エチル25g及びN,N’-アゾビスイソブチロニトリル0.20gを仕込み、窒素ガスを導入しながら、30分間攪拌混合した後、70℃に加熱して、ラジカル重合を開始した。約1時間経過したとき、反応混合物の粘度の上昇認められた。この後、反応混合物に酢酸エチルを追加しながら、温度をほぼ一定に保ち、更に、8時間重合を続けた。
参考例3で得られた反応性ポリマー10gを酢酸エチルに室温で溶解させ、10重量%濃度の反応性ポリマー溶液を調製した。これに多官能イソシアネート(ヘキサメチレンジイソシアネート/トリメチロールプロパンアダクト体、酢酸エチル溶液、固形分25%、日本ポリウレタン工業(株)製コロネートHL)3.14gを加え、溶解させて、反応性ポリマーと多官能イソシアネートを含む塗工液を調製した。
(反応性ポリマーの調製)
還流冷却管を備えた500mL容量の3つ口フラスコにメチルメタクリレート98g、4-ヒドロキシブチルアクリレート2.0g、酢酸エチル25g及びN,N’-アゾビスイソブチロニトリル0.20gを仕込み、窒素ガスを導入しながら、30分間攪拌混合した後、70℃に加熱して、ラジカル重合を開始した。約2時間経過したとき、反応混合物の粘度の上昇が認められ、その後、酢酸エチルを追加しながら、温度をほぼ一定に保ち、更に、8時間重合を続けた。
還流冷却管を備えた300mL容量の3つ口フラスコに窒素ガスを導入しながら、ポリヘキサメチレンカーボネートジオール(日本ポリウレタン工業(株)製ニッポラン980R)18.5gとトルエン25.2gを投入し、攪拌、溶解させた後、ポリヘキサメチレンジイソシアネート(日本ポリウレタン工業(株)製HDI)4.98gとトルエン9.98gを混合した溶液を混合した。均一に攪拌混合した後、60℃に加熱し、15時間反応させた。室温に冷却し、更に、トルエン136.98gを加え、12重量%濃度の末端イソシアネート基ポリカーボネートウレタンプレポリマーのトルエン溶液を得た。
参考例4で得られた反応性ポリマー6gを室温でトルエンに溶解させ、12重量%濃度の反応性ポリマー溶液50gを調製し、これと参考例4で得られた12重量%濃度の末端イソシアネート基ポリカーボネートウレタンプレポリマーのトルエン溶液22.5gを混合し、攪拌した。更に、得られた混合溶液にトルエン145gを加えて、固形分濃度4重量%の塗工液を調製した。
(反応性ポリマーの調製)
還流冷却管を備えた500mL容量の3つ口フラスコにメチルメタクリレート98g、4-ヒドロキシブチルアクリレート2.0g、酢酸エチル25g及びN,N’-アゾビスイソブチロニトリル0.20gを仕込み、窒素ガスを導入しながら、30分間攪拌混合した後、70℃に加熱して、ラジカル重合を開始した。約2時間経過したとき、反応混合物の粘度の上昇が認められ、その後、酢酸エチルを追加しながら温度をほぼ一定に保ち、更に、8時間重合を続けた。
還流冷却管を備えた300mL容量の3つ口フラスコに窒素ガスを導入しながら、ポリヘキサメチレンカーボネートジオール(前記ニッポラン980R)20gと酢酸エチル20.94gを投入し、攪拌、溶解させた後、前記と同じ多官能イソシアネート(ヘキサメチレンジイソシアネート/トリメチロールプロパンアダクト体、酢酸エチル溶液、固形分25%、日本ポリウレタン工業(株)製コロネートHL)24.15gを混合した。均一に攪拌した後、60℃に加熱し、15時間反応させた。室温に冷却し、更に、酢酸エチル151.88gを加え、12重量%濃度の末端イソシアネート基ポリカーボネートウレタンプレポリマーの酢酸エチル溶液を得た。
参考例5で得られた反応性ポリマー6gを酢酸エチルに室温で溶解させ、12重量%濃度の反応性ポリマー溶液50gを調製し、これに参考例5で得られた12重量%濃度のウレタンプレポリマーの酢酸エチル溶液16gを加え、攪拌しながら、80℃に加熱し、20時間反応させた。この後、反応混合物を冷却した後、これに酢酸エチル132gを加えて、固形分濃度4重量%の塗工液を調製した。
参考例5で得られた反応性ポリマー6.0gを酢酸エチルに室温で溶解させ、12重量%濃度の反応性ポリマー溶液50gを調製し、これに参考例5で得られた12重量%濃度のウレタンプレポリマーの酢酸エチル溶液60gを加え、攪拌しながら、80℃に加熱し、20時間反応させた。得られた反応混合物を冷却した後、これに酢酸エチル220gを加えて、固形分濃度4重量%の塗工液を調製した。
(反応性ポリマーの調製)
還流冷却管を備えた500mL容量の3つ口フラスコにメチルメタクリレート98g、4-ヒドロキシブチルアクリレート2.0g、酢酸エチル25g及びN,N’-アゾビスイソブチロニトリル0.20gを仕込み、窒素ガスを導入しながら、30分間攪拌混合した後、70℃に加熱して、ラジカル重合を開始した。約2時間経過したとき、反応混合物の粘度の上昇が認められ、その後、酢酸エチルを追加しながら温度をほぼ一定に保ち、更に、8時間重合を続けた。
還流冷却管を備えた300mL容量の3つ口フラスコに窒素ガスを導入しながら、1分子中に炭素数の異なるアルキレン鎖を有するポリアルキレンカーボネートジオール(旭化成ケミカルズ(株)製デュラノールG3452)18gとトルエン41.68gを投入し、攪拌、溶解させた後、多官能イソシアネート(日本ポリウレタン工業(株)コロネート2770)9.79gを混合した。均一に攪拌混合した後、60℃に加熱し、15時間反応させた。室温に冷却し、更にトルエン152.83gを加え、12.5重量%濃度のウレタンプレポリマー溶液を得た。
参考例6で得られた反応性ポリマー9gを室温でトルエンに溶解させ、10重量%濃度の反応性ポリマー溶液90gを調製し、これと12.5重量%濃度のウレタンプレポリマー溶液32.4gを混合し、攪拌した。更に、得られた混合溶液にトルエン95.1gを加えて、固形分濃度6重量%の塗工液を調製した。
(反応性ポリマーの調製)
還流冷却管を備えた500mL容量の3つ口フラスコにメチルメタクリレート98g、4-ヒドロキシブチルアクリレート2.0g、酢酸エチル25g及びN,N’-アゾビスイソブチロニトリル0.20gを仕込み、窒素ガスを導入しながら、30分間攪拌混合した後、70℃に加熱して、ラジカル重合を開始した。約2時間経過したとき、反応混合物の粘度の上昇が認められ、その後、酢酸エチルを追加しながら温度をほぼ一定に保ち、更に、8時間重合を続けた。
還流冷却管を備えた300mL容量の3つ口フラスコに窒素ガスを導入しながら、1分子中に炭素数の異なるアルキレン鎖を有するポリアルキレンカーボネートジオール(旭化成ケミカルズ(株)製デュラノールG3452)18gとトルエン39.23gを投入し、攪拌、溶解させた後、多官能イソシアネート(日本ポリウレタン工業(株)コロネート2770)8.16gを混合した。均一に攪拌混合した後、60℃に加熱し、15時間反応させた。室温に冷却し、更にトルエン143.86gを加え、12.5重量%濃度のウレタンプレポリマー溶液を得た。
参考例7で得られた反応性ポリマー6gを室温でトルエンに溶解させ、10重量%濃度の反応性ポリマー溶液60gを調製し、これと12.5重量%濃度のウレタンプレポリマー溶液48gを混合し、攪拌した。更に、得られた混合溶液にトルエン92gを加えて、固形分濃度6重量%の塗工液を調製した。
参考例2で得られたポリエチレン樹脂多孔質フィルムの片面に空孔率97%、厚さ5μmのポリテトラフルオロエチレン樹脂多孔質フィルムを積層し、担持させた。
なお、本出願は、2008年3月31日付けで出願された日本特許出願(特願2008-094392)に基づいており、その全体が引用により援用される。
また、ここに引用されるすべての参照は全体として取り込まれる。
Claims (9)
- 多孔質基材、および
前記多孔質基材の少なくとも1つの表面に担持された架橋ポリマーの層
を含む電池用セパレータであって、
前記架橋ポリマーが、
(a)分子中に活性水素を含む反応性基を有する反応性ポリマーと、
(b)末端イソシアネート基ポリカーボネートウレタンプレポリマー
との反応によって得られる電池用セパレータ。 - 活性水素を含む反応性基が、ヒドロキシ基、カルボキシル基及びアミノ基から選ばれる少なくとも1種である請求項1に記載の電池用セパレータ。
- 多孔質基材がポリオレフィン樹脂多孔質フィルムである請求項1に記載の電池用セパレータ。
- ポリオレフィン樹脂多孔質フィルムがポリエチレン樹脂多孔質フィルムである請求項3に記載の電池用セパレータ。
- 請求項1から4のいずれかに記載のセパレータ、および
前記セパレータを挟んで積層された正極と負極
を含む電極/セパレータ接合体であって、
架橋ポリマーによって正極と負極の少なくとも一方が多孔質基材に接着されている電極/セパレータ接合体。 - 請求項5に記載の電極/セパレータ接合体を含む電池。
- さらに非水電解液を含み、架橋ポリマーの層が少なくとも正極に対面している請求項6に記載の電池。
- 請求項1から4のいずれかに記載のセパレータを挟んで正極と負極を積層すること、
得られた積層体を電池容器内に仕込んだ後、非水電解液を上記電池容器内に注入すること、および
架橋ポリマーによって正極と負極の少なくとも一方が多孔質基材に接着されてなる電極/セパレータ接合体を形成すること
を含む電池の製造方法。 - 架橋ポリマーの層が少なくとも正極に対面するようにセパレータを挟んで正極と負極を積層する請求項8に記載の電池の製造方法。
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN2009801118756A CN101983444B (zh) | 2008-03-31 | 2009-03-31 | 电池用隔膜和使用所述隔膜的电池 |
US12/935,735 US9142818B2 (en) | 2008-03-31 | 2009-03-31 | Battery separator and battery using the same |
EP09727986.3A EP2262038B1 (en) | 2008-03-31 | 2009-03-31 | Battery separator and battery using the same |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2008-094392 | 2008-03-31 | ||
JP2008094392 | 2008-03-31 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2009123218A1 true WO2009123218A1 (ja) | 2009-10-08 |
Family
ID=41135586
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2009/056720 WO2009123218A1 (ja) | 2008-03-31 | 2009-03-31 | 電池用セパレータとこれを用いてなる電池 |
Country Status (6)
Country | Link |
---|---|
US (1) | US9142818B2 (ja) |
EP (1) | EP2262038B1 (ja) |
JP (1) | JP5337550B2 (ja) |
KR (1) | KR101474591B1 (ja) |
CN (1) | CN101983444B (ja) |
WO (1) | WO2009123218A1 (ja) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2021187237A1 (ja) * | 2020-03-17 | 2021-09-23 | 第一工業製薬株式会社 | 二次電池セパレータ用ポリウレタン樹脂水分散体、二次電池セパレータ及び二次電池 |
Families Citing this family (20)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5771621B2 (ja) * | 2010-10-27 | 2015-09-02 | 株式会社クラレ | 非水系電池用セパレータ及びそれを用いた非水系電池、ならびに非水系電池用セパレータの製造方法 |
WO2013062997A1 (en) | 2011-10-28 | 2013-05-02 | Lubrizol Advanced Materials, Inc. | Polyurethane-based electrode binder compositions and electrodes thereof for electrochemical cells |
JP6105226B2 (ja) * | 2012-08-09 | 2017-03-29 | 三洋電機株式会社 | 非水電解質二次電池 |
WO2014083988A1 (ja) * | 2012-11-30 | 2014-06-05 | 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 |
US10186716B2 (en) | 2014-11-10 | 2019-01-22 | Lanxess Solutions Us Inc. | Non-aqueous flow cell comprising a polyurethane separator |
EP3218947B1 (en) * | 2014-11-10 | 2018-12-19 | LANXESS Solutions US Inc. | Energy storage device comprising a polyurethane separator |
JP5988344B1 (ja) * | 2016-04-20 | 2016-09-07 | 第一工業製薬株式会社 | 二次電池セパレータ用ポリウレタン樹脂水分散体、二次電池セパレータおよび二次電池 |
CN107611321B (zh) * | 2016-07-11 | 2020-06-12 | 宁德新能源科技有限公司 | 隔离膜及二次电池 |
US9972838B2 (en) | 2016-07-29 | 2018-05-15 | Blue Current, Inc. | Solid-state ionically conductive composite electrodes |
US9926411B1 (en) | 2017-03-03 | 2018-03-27 | Blue Current, Inc. | Polymerized in-situ hybrid solid ion-conductive compositions |
JP7013682B2 (ja) * | 2017-06-08 | 2022-02-01 | Dic株式会社 | ウレタン(メタ)アクリレート樹脂 |
KR102136547B1 (ko) * | 2017-09-05 | 2020-07-22 | 주식회사 엘지화학 | 전해질 조성물, 전해질 필름, 및 전기변색소자 |
CN109295512B (zh) * | 2018-09-28 | 2019-05-21 | 青岛大学 | 一种含氟封端结构的聚碳酸酯/聚酰亚胺复合纤维膜的制备方法 |
CN108963169B (zh) * | 2018-09-28 | 2019-05-14 | 青岛大学 | 电池用隔膜和使用所述隔膜的电池 |
US11581570B2 (en) | 2019-01-07 | 2023-02-14 | Blue Current, Inc. | Polyurethane hybrid solid ion-conductive compositions |
KR20210006242A (ko) * | 2019-07-08 | 2021-01-18 | 주식회사 엘지화학 | 이차전지용 분리막 및 이를 포함하는 이차전지 |
JPWO2021033589A1 (ja) * | 2019-08-20 | 2021-02-25 | ||
US11394054B2 (en) | 2019-12-20 | 2022-07-19 | Blue Current, Inc. | Polymer microspheres as binders for composite electrolytes |
CN115336039A (zh) | 2019-12-20 | 2022-11-11 | 蓝色电流股份有限公司 | 具有粘合剂的复合电解质 |
CN117458084B (zh) * | 2023-12-19 | 2024-03-19 | 宁德新能源科技有限公司 | 一种二次电池和电子装置 |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH1180395A (ja) * | 1997-09-09 | 1999-03-26 | Nitto Denko Corp | 多孔質膜および非水電解液電池用セパレータ |
JP2004356102A (ja) * | 2003-05-28 | 2004-12-16 | Celgard Inc | リチウムポリマー電池用の電池セパレータ |
JP2006012561A (ja) * | 2004-06-24 | 2006-01-12 | Nitto Denko Corp | 電池用正極/反応性ポリマー担持多孔質フィルム/負極積層体 |
JP2007123254A (ja) * | 2005-09-29 | 2007-05-17 | Nitto Denko Corp | 電池用セパレータのための反応性ポリマー担持多孔質フィルムとそれを用いた電池の製造方法 |
JP2007157459A (ja) | 2005-12-02 | 2007-06-21 | Sony Corp | 非水電解質電池 |
JP2007157569A (ja) * | 2005-12-07 | 2007-06-21 | Nitto Denko Corp | 電池用セパレータのための反応性ポリマー担持多孔質フィルムとそれを用いる電池の製造方法 |
JP2007157570A (ja) * | 2005-12-07 | 2007-06-21 | Nitto Denko Corp | 電池用セパレータのためのポリマー担持多孔質フィルムとそれを用いる電池の製造方法 |
JP2008094392A (ja) | 2006-10-11 | 2008-04-24 | Ti Group Automotive Systems Llc | 取付けブラケット |
JP2009110683A (ja) * | 2007-10-26 | 2009-05-21 | Nitto Denko Corp | 電池用セパレータのための反応性ポリマー層担持多孔質フィルムとその利用 |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH05310989A (ja) | 1992-04-30 | 1993-11-22 | Mitsubishi Kasei Corp | ポリエチレン多孔膜 |
JP3549290B2 (ja) | 1995-06-29 | 2004-08-04 | 東燃化学株式会社 | ポリオレフィン微多孔膜及びその製造方法 |
JP3416365B2 (ja) | 1995-11-30 | 2003-06-16 | 三洋電機株式会社 | 非水電解液電池 |
JP3225864B2 (ja) | 1996-12-04 | 2001-11-05 | 三菱電機株式会社 | リチウムイオン二次電池及びその製造方法 |
JPH11329439A (ja) | 1998-05-12 | 1999-11-30 | Sony Corp | 非水電解液二次電池 |
JP4412808B2 (ja) * | 2000-05-12 | 2010-02-10 | パナソニック株式会社 | リチウムポリマー二次電池 |
JP2002175837A (ja) | 2000-12-06 | 2002-06-21 | Nisshinbo Ind Inc | 高分子ゲル電解質及び二次電池並びに電気二重層キャパシタ |
JP4791087B2 (ja) * | 2004-09-30 | 2011-10-12 | 日東電工株式会社 | 反応性ポリマー担持多孔質フィルムとその製法 |
-
2009
- 2009-03-30 JP JP2009082012A patent/JP5337550B2/ja not_active Expired - Fee Related
- 2009-03-31 WO PCT/JP2009/056720 patent/WO2009123218A1/ja active Application Filing
- 2009-03-31 CN CN2009801118756A patent/CN101983444B/zh not_active Expired - Fee Related
- 2009-03-31 KR KR1020107021895A patent/KR101474591B1/ko active IP Right Grant
- 2009-03-31 US US12/935,735 patent/US9142818B2/en not_active Expired - Fee Related
- 2009-03-31 EP EP09727986.3A patent/EP2262038B1/en not_active Not-in-force
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH1180395A (ja) * | 1997-09-09 | 1999-03-26 | Nitto Denko Corp | 多孔質膜および非水電解液電池用セパレータ |
JP2004356102A (ja) * | 2003-05-28 | 2004-12-16 | Celgard Inc | リチウムポリマー電池用の電池セパレータ |
JP2006012561A (ja) * | 2004-06-24 | 2006-01-12 | Nitto Denko Corp | 電池用正極/反応性ポリマー担持多孔質フィルム/負極積層体 |
JP2007123254A (ja) * | 2005-09-29 | 2007-05-17 | Nitto Denko Corp | 電池用セパレータのための反応性ポリマー担持多孔質フィルムとそれを用いた電池の製造方法 |
JP2007157459A (ja) | 2005-12-02 | 2007-06-21 | Sony Corp | 非水電解質電池 |
JP2007157569A (ja) * | 2005-12-07 | 2007-06-21 | Nitto Denko Corp | 電池用セパレータのための反応性ポリマー担持多孔質フィルムとそれを用いる電池の製造方法 |
JP2007157570A (ja) * | 2005-12-07 | 2007-06-21 | Nitto Denko Corp | 電池用セパレータのためのポリマー担持多孔質フィルムとそれを用いる電池の製造方法 |
JP2008094392A (ja) | 2006-10-11 | 2008-04-24 | Ti Group Automotive Systems Llc | 取付けブラケット |
JP2009110683A (ja) * | 2007-10-26 | 2009-05-21 | Nitto Denko Corp | 電池用セパレータのための反応性ポリマー層担持多孔質フィルムとその利用 |
Non-Patent Citations (1)
Title |
---|
See also references of EP2262038A4 |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2021187237A1 (ja) * | 2020-03-17 | 2021-09-23 | 第一工業製薬株式会社 | 二次電池セパレータ用ポリウレタン樹脂水分散体、二次電池セパレータ及び二次電池 |
Also Published As
Publication number | Publication date |
---|---|
CN101983444A (zh) | 2011-03-02 |
KR20100132965A (ko) | 2010-12-20 |
EP2262038A4 (en) | 2011-07-06 |
EP2262038B1 (en) | 2014-06-25 |
JP2009266812A (ja) | 2009-11-12 |
KR101474591B1 (ko) | 2014-12-18 |
EP2262038A1 (en) | 2010-12-15 |
CN101983444B (zh) | 2013-09-11 |
JP5337550B2 (ja) | 2013-11-06 |
US9142818B2 (en) | 2015-09-22 |
US20110135989A1 (en) | 2011-06-09 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5337550B2 (ja) | 電池用セパレータとこれを用いてなる電池 | |
JP5337549B2 (ja) | 電池用セパレータとこれを用いてなる電池 | |
TWI479725B (zh) | 分隔器及含有此分隔器之電化學裝置 | |
JP2007123254A (ja) | 電池用セパレータのための反応性ポリマー担持多孔質フィルムとそれを用いた電池の製造方法 | |
JP2004342572A (ja) | 電池用セパレータのための部分架橋接着剤担持多孔質フィルムとその利用 | |
WO2004091014A1 (ja) | 電池用セパレータのための接着剤担多孔質フィルムとその利用 | |
JP2009110683A (ja) | 電池用セパレータのための反応性ポリマー層担持多孔質フィルムとその利用 | |
JP5260075B2 (ja) | 電池用セパレータ用反応性ポリマー担持多孔質フィルムとそれより得られる電極/セパレータ接合体 | |
JP2007157569A (ja) | 電池用セパレータのための反応性ポリマー担持多孔質フィルムとそれを用いる電池の製造方法 | |
EP2159863A1 (en) | Crosslinkable polymer-loaded porous film for battery separator and use thereof | |
JP5422088B2 (ja) | 電池用セパレータとこれを用いてなる電池 | |
JP4564240B2 (ja) | 電池用セパレータのための反応性ポリマー担持多孔質フィルムとそれを用いた電池の製造方法 | |
JP4456422B2 (ja) | 電池用正極/反応性ポリマー担持多孔質フィルム/負極積層体 | |
JP4601338B2 (ja) | 電池用正極/反応性ポリマー担持多孔質フィルム/負極積層体 | |
JP2007035542A (ja) | 電池用セパレータとこれを用いる電池の製造方法 | |
JP2007035555A (ja) | 電池用セパレータとこれを用いる電池の製造方法 | |
JP5680241B2 (ja) | 電池用セパレータ | |
JP2009193743A (ja) | 電池用セパレータのための架橋性ポリマー担持多孔質フィルムとそれより得られる電池用セパレータと電極/セパレータ接合体 | |
JP5260073B2 (ja) | 電池用セパレータとそれより得られる電極/セパレータ接合体 | |
JP2011192565A (ja) | 電池用セパレータ | |
JP2014135288A (ja) | 電池用セパレータ |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 200980111875.6 Country of ref document: CN |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 09727986 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2009727986 Country of ref document: EP |
|
ENP | Entry into the national phase |
Ref document number: 20107021895 Country of ref document: KR Kind code of ref document: A |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 12935735 Country of ref document: US |