JP5235109B2 - Nonaqueous electrolyte battery separator and nonaqueous electrolyte battery - Google Patents

Description

  The present invention relates to a separator for constituting a nonaqueous electrolyte battery having a gel-like nonaqueous electrolyte, and a nonaqueous electrolyte battery using the separator.

  In recent years, the demand for mobile terminal devices such as mobile phones, notebook personal computers, and personal digital assistants (PDAs) has been rapidly expanding. And along with the reduction in size and weight and the increase in functionality, there has been a demand for higher energy density of non-aqueous electrolyte batteries such as lithium secondary batteries used as a power source, and the capacity is increasing year by year. . In addition, there is an increasing need to ensure the safety and reliability of batteries.

  Under such circumstances, as a means for improving the safety of the battery, instead of the conventional liquid electrolyte, a so-called gel electrolyte in which a polymer is used as a host and the electrolyte is held in the matrix was used. Batteries have been proposed (for example, Patent Documents 1 to 4) and put into practical use.

  However, in batteries using gel electrolyte, there is no problem such as leakage, but in abnormal situations where the internal temperature becomes very high, such as overcharge or short circuit, the viscosity of the gel electrolyte decreases and short circuit occurs. It becomes easier to be induced. In this respect, the safety of a battery using a gel electrolyte is not sufficient, and as with a battery having a conventional liquid electrolyte, the holes are closed by heat melting of the constituent materials at high temperatures. At present, safety is ensured by using a polyolefin-based separator having a function capable of increasing resistance (so-called shutdown function).

  Moreover, as a method of producing a battery having these gel electrolytes, (1) a laminated electrode body or a wound electrode body similar to a battery having a liquid electrolyte (non-aqueous electrolyte solution) is produced, and an exterior material (battery Case), a non-aqueous electrolyte containing a substance (monomer, macromer or non-crosslinked polymer and gelling agent, etc.) that is a raw material of the polymer constituting the gel electrolyte, and a reaction initiator is injected into the outer packaging. Thereafter, a method of gelling the non-aqueous electrolyte by polymerizing or crosslinking the raw material; (2) After applying a solution containing a polymer constituting the gel electrolyte to the electrode surface, removing the solvent and drying A method of producing a laminated electrode body or a wound electrode body using the electrode and inserting the electrode body into an outer packaging material, injecting the nonaqueous electrolyte solution therein, and gelling the nonaqueous electrolyte solution in the battery; (3 ) Gel electrolyte on the electrode surface Applying a raw material of the polymer to be formed and a reaction initiator, forming a polymer by cross-linking reaction with heat or light, etc., and then using this electrode to produce a laminated electrode body or a wound electrode body There has been proposed a method of inserting a non-aqueous electrolyte into an exterior material, and injecting the non-aqueous electrolyte therein to gel the non-aqueous electrolyte in the battery.

  However, in the method (1), since the nonaqueous electrolyte to be injected contains a reaction initiator, the gelation reaction proceeds in a state where the nonaqueous electrolyte is left standing, so that there is a problem in its storage stability. In addition, the reaction initiator remaining in the battery may affect the battery characteristics. Further, when the viscosity of the nonaqueous electrolyte to be injected is low, a gel may also be formed in the gaps of the electrodes, leading to an increase in interfacial resistance. It gets worse and can't increase productivity.

  In the method (2), when a polymer solution is applied to the electrodes, the polymer may enter the gaps between the electrodes, leading to an increase in interface resistance, which may cause a decrease in battery characteristics. In order to prevent such an increase in interfacial resistance, a method of applying a polymer by impregnating a block solution in advance in an electrode has also been proposed (Patent Document 5). However, when such a method is used, it is necessary to remove the block liquid under the coating film coated with the polymer, and the drying time is longer than the drying of the normal electrode and polymer coating film. Takes time and productivity is not good. Further, when the drying is insufficient and the solvent or moisture remains on the electrode, there arises a problem that the battery characteristics are adversely affected.

  Furthermore, in the method (3), when the gel electrolyte is produced on the electrode surface or after the production, it is necessary to work in an environment in which water absorption is avoided, so that the handling is troublesome and the productivity is also poor. There is a point.

Japanese Patent No. 29987474 JP 2002-25621 A US Pat. No. 5,453,335 JP 2002-367777 A JP 2002-343438 A

  The present invention has been made in view of the above circumstances, and its purpose is to use a separator suitable for constituting a non-aqueous electrolyte battery having a gel-like non-aqueous electrolyte, and the battery characteristics. Another object of the present invention is to provide a non-aqueous electrolyte battery that is excellent in safety and productivity.

  The separator for a nonaqueous electrolyte battery of the present invention that has achieved the above object forms a crosslinked structure with a resin (A) that is stable at room temperature with respect to a nonaqueous electrolyte and has a heat resistant temperature of 150 ° C. or higher. And a resin (B) that contains a reactive group and can be dissolved in a non-aqueous electrolyte.

The separator for a nonaqueous electrolyte battery of the present invention that has achieved the above object forms a crosslinked structure with a resin (A) that is stable at room temperature with respect to a nonaqueous electrolyte and has a heat resistant temperature of 150 ° C. or higher. contain reactive groups for, and then dissolved in the non-aqueous electrolytic solution have a resin (B) that form a vacancy, the resin (B) is an acrylic resin containing epoxy groups or oxetane groups or characterized in Oh Rukoto in microparticles of a methacrylic resin.

  Moreover, since it is not necessary to add a crosslinking agent etc. separately for gelatinization of a nonaqueous electrolyte by using the separator of this invention, the fall of the battery characteristic by these can also be suppressed.

  In addition, according to the separator of the present invention, since the gel electrolyte can be introduced into the battery very easily, the productivity of the battery can be improved.

  The “gel” in the non-aqueous electrolyte referred to in this specification includes the same state as an electrolyte called a “gel electrolyte” in the battery industry (strict Even if it is not a gel in the meaning, the liquid has almost no fluidity or the liquid has stopped flowing.

  According to the present invention, it is possible to provide a non-aqueous electrolyte battery having excellent battery characteristics (particularly charge / discharge cycle characteristics) and safety, and good productivity.

  The separator of the present invention is stable at room temperature with respect to a non-aqueous electrolyte (a non-aqueous electrolyte used for constituting a non-aqueous electrolyte battery. Details will be described later), and has a heat resistant temperature of 150 ° C. It has a resin (A) and a resin (B) that contains a reactive group for forming a crosslinked structure and can be dissolved in a nonaqueous electrolytic solution.

  As described above, the resin (A) is a main component of the separator in the nonaqueous electrolyte battery. In addition, the resin (B) dissolves in the non-aqueous electrolyte solution in the non-aqueous electrolyte battery configured using the separator of the present invention to form the pores of the separator, and further, external stimulus such as heat is applied. As a result, it is a component for forming a gel electrolyte by forming a cross-linked structure with the reactive group and incorporating a non-aqueous electrolyte therein.

  In the non-aqueous electrolyte battery using the separator of the present invention, the resin (B) in the separator is dissolved in the non-aqueous electrolyte at the stage of assembling the battery, and then an external stimulus is applied to the resin (B). Forms a cross-linked structure to produce a gel electrolyte. Therefore, a gel electrolyte with high homogeneity is generated over the entire battery, so that the battery is very excellent in safety and battery characteristics.

  The resin (A) is particularly a resin that is stable at room temperature with respect to the non-aqueous electrolyte, has a heat-resistant temperature of 150 ° C. or higher, and is stable with respect to electrochemical reactions such as charge / discharge in the non-aqueous electrolyte battery. There is no limit. In the resin (A), “stable at room temperature with respect to the non-aqueous electrolyte” means that the resin (A) is not dissolved or flowed when exposed to the non-aqueous electrolyte. “C or higher” means a state in which the shape of the separator can be maintained without being thermally decomposed, dissolved, or flowed when exposed to a non-aqueous electrolyte at a temperature of at least 150 ° C. inside the battery. I mean. The heat resistant temperature of the resin (A) is preferably 200 ° C. or higher. By using a heat-resistant resin as described above for the resin (A), the shape of the separator can be maintained even when the battery is exposed to a high temperature, so that a short circuit at a high temperature can be prevented.

  Moreover, as resin (A), it is preferable that glass transition temperature (Tg) is below room temperature. If the resin has a Tg of room temperature or lower, the flexibility is high and the resistance to deformation of the separator is high. For example, when forming a wound electrode body, problems such as cracking of the separator are unlikely to occur.

  In addition, Tg of resin (A) as used in this specification is a value measured using a differential scanning calorimeter (DSC) according to the prescription | regulation of JISK7121.

  Specific examples of the resin (A) include, for example, polyvinylidene fluoride (PVDF), ethylene-vinyl alcohol resin (EVOH), ethyl acrylate resin (EEA), ethylene-vinyl acetate resin (EVA), and styrene-butadiene rubber (SBR). ), Nitrile rubber (NBR), (meth) acrylic rubber (MBR), ethylene-propylene rubber (EPR), and derivatives thereof. Of the various resins described above, rubber (SBR, NBR, MBR, EPR) is preferably a crosslinked product. Only 1 type may be used for resin (A) among the resin of the said illustration, and 2 or more types may be used together.

  For example, the separator of the present invention can contain a filler or use a porous substrate, as will be described later. In such a case, the resin (A) is composed of fillers or Also, it can act as a binder for binding the filler and the porous substrate.

  The content of the resin (A) in the separator is the total volume of the constituent components of the separator before being immersed in the non-aqueous electrolyte [however, in the case of using a porous substrate described later, the constituent components excluding the porous substrate] During the entire volume of ], Preferably 10 to 50% by volume.

The resin (B) contains a reactive group that can be dissolved in the non-aqueous electrolyte and that forms a crosslinked structure. Reactive groups, heat, ultraviolet light, react by an external stimulus such as radiation cross-linking the resin (B), all SANYO a non-aqueous electrolyte can be gelled, specifically, an epoxy group or an oxetane group It is . The resin (B) may contain both an epoxy group and an oxetane group as a reactive group.

  The resin (B) is preferably fine particles. Resin (B) dissolves in the non-aqueous electrolyte in the non-aqueous electrolyte battery, thereby forming the pores of the separator. When fine particles are used as the resin (B), the shape control of the pores formed by the dissolution becomes easier, and the ions in the separator can be moved smoothly.

  When the resin (B) is a fine particle, the particle size may be smaller than, for example, the thickness of the separator, but in order to make the movement of ions in the separator smoother, the average particle size is 0.1 μm or more. It is preferable that the thickness is 0.3 μm or more. That is, if the average particle size of the resin (B) fine particles is too small, the pores of the separator formed by dissolution of the resin (B) may become too small, which may hinder the movement of ions. Aggregation tends to occur, which may make it difficult to form pores uniformly.

  When the resin (B) is a fine particle, if the particle size is too large, the diameter of the pores formed by the dissolution of the resin (B) becomes too large, and a short circuit between the positive and negative electrodes is likely to occur in the battery. The average particle size is preferably 5 μm or less, and more preferably 3 μm or less.

  The average particle size of the fine particles [resin (B) fine particles, filler described later, resin (C) fine particles and composite fine particles] described herein is, for example, a laser scattering particle size distribution meter (for example, HORIBA "LA-920") manufactured by the manufacturer can be defined as the number average particle diameter measured by dispersing these fine particles in a medium in which the fine particles are not dissolved.

Specific examples of the resin (B) include the above-described reactive group, can be dissolved in a non-aqueous electrolyte, and are electrochemically stable, and can be decomposed or gasified by an electrochemical reaction such as charge / discharge in a battery. all SANYO does not cause side reactions such as generation, specifically, acrylic resin, methacrylic resin [hereinafter collectively acrylic resin and methacrylic resin referred to as "(meth) acrylic resin". It is a. Only 1 type may be used for resin (B) among the said illustrations, and 2 or more types may be used together. Incidentally, (meth) acrylic resin, Ru micronized readily der.

  More specifically, as the resin (B), a resin having a structure represented by the following general formula (1) into which a crosslinkable side chain (a side chain containing the reactive group) is introduced can be used.

(In the general formula (1), R ¹ and R ³ are each a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ² is an alkyl group having 1 to 3 carbon atoms, a hydroxyalkyl group, or an alkylene oxide group, R ⁴ represents an alkyl group having 1 to 6 carbon atoms in which at least one hydrogen atom is substituted with an oxetane group or an alicyclic epoxy group, and m and n each represents an integer of 100 to 1000.)

Since the resin represented by the general formula (1) contains an oxetane group or an alicyclic epoxy group as a reactive group in the side chain, as described above, when an external stimulus such as heat is applied in the battery, Since a lithium salt (a lithium salt exemplified later such as LiPF ₆ or LiBF ₄ ) in the non-aqueous electrolyte is reacted as an initiator to form a crosslinked structure, a good gel electrolyte can be generated.

  The resin represented by the general formula (1) is, for example, a co-polymer having a unit represented by the following general formula (2) and / or the following general formula (3) and a unit represented by the following general formula (4). It is preferably a coalescence.

(Formula (2), (3) and (4) ^in, R 5, ^{R 7,} and ^{R 8} is a hydrogen atom or a methyl group, ^{R 6} and ^{R 9} represents an alkyl group having 1 to 6 carbon atoms. )

  The resin represented by the general formula (1) is a copolymer having the unit represented by the general formula (2) and / or the general formula (3) and the unit represented by the general formula (4). In this case, the ratio of the unit represented by the general formula (4) in the entire copolymer unit is preferably 50 mol% or more, more preferably 75 mol% or more, and 98 mol. % Or less, and more preferably 90 mol% or less. In other words, the total ratio of the unit represented by the general formula (2) and the unit represented by the general formula (3) is preferably 2 mol% or more in all units of the copolymer. % Or more, more preferably 50 mol% or less, and even more preferably 25 mol% or less. If the ratio of the unit represented by the general formula (4) is too small, the crosslink density when gelled becomes too high, and the electrolyte holding ability of the gel may be reduced in the battery. On the other hand, when the ratio of the unit represented by the general formula (4) is too large, the number of side chains having a crosslinking ability may be reduced, and the crosslinking ability may be lowered.

  Note that either one of the unit represented by the general formula (2) and the unit represented by the general formula (3) may be used, or both may be used simultaneously. The ratio of the unit represented by the general formula (2) and the unit represented by the general formula (3) is not particularly limited, and the total ratio of these units in all units of the copolymer is It is sufficient to satisfy the preferable value of.

  The copolymer having the unit represented by the general formula (2) and / or the general formula (3) and the unit represented by the general formula (4) has the following general formula (5) and / or the following general formula. It can be obtained by copolymerizing the monomer represented by (6) and the monomer represented by the following general formula (7). Since each of the monomers has a relatively close reactivity, the copolymer is usually obtained as a random copolymer or a block copolymer.

[In the general formulas (5), (6) and (7), R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ are the same as those in the general formulas (2), (3) and (4), respectively. The same. ]

  In synthesizing the copolymer, for example, each monomer and a polymerization initiator (potassium persulfate, etc.) are added to a dispersion medium (water, etc.), and in a nitrogen atmosphere at 30-80 ° C. A method of dispersion polymerization with stirring can be employed. By doing so, the copolymer can be synthesized in the form of fine particles. Alternatively, the copolymer fine particles may be obtained by performing solution polymerization in a solvent to obtain a copolymer, and then dispersing in a dispersion medium such as water to make fine particles.

  The monomer represented by the general formula (5) can be produced by reacting an acid chloride such as acrylic acid chloride or methacrylic acid chloride with 3-ethyl-3-hydroxymethyloxetane. Moreover, the monomer shown by the said General formula (5), the said General formula (6), and the said General formula (7) can be obtained as a commercial item.

  The amount of the resin (B) in the separator is increased by increasing the porosity of the separator after the resin (B) is dissolved in the non-aqueous electrolyte in the battery to improve the movement of ions. From the viewpoint of enhancing battery characteristics such as characteristics, the total volume of the constituent components of the separator before being immersed in the non-aqueous electrolyte [However, when using the porous substrate described later, the constituent components other than the porous substrate are excluded. In total volume. The same applies hereinafter for the amount of resin (B) in the separator. ] It is preferable that it is 10 volume% or more, and it is more preferable that it is 20 volume% or more. However, if the resin (B) content is too high, the porosity of the separator after the resin (B) is dissolved in the non-aqueous electrolyte becomes too high, resulting in a decrease in the strength of the separator or a short circuit. The content of the resin (B) in the separator is preferably 70% by volume or less, and more preferably 50% by volume or less.

  Moreover, it is desirable that the separator of the present invention contains a filler. By including a filler in the separator, it is possible to obtain an effect of increasing strength and improving short circuit resistance, or securing pores of the separator by voids between the fillers, and smoothing the movement of ions.

  Any filler may be used as long as it is stable in the nonaqueous electrolyte and electrochemically stable. However, a filler having a heat resistant temperature of 150 ° C. or higher is preferable, and an inorganic filler is more preferable.

Specific examples of the constituent material of the inorganic filler include, for example, iron oxide, Al ₂ O ₃ (alumina), SiO ₂ (silica), TiO ₂ , BaTiO ₃ , ZrO ₂ and other inorganic oxides; aluminum nitride, silicon nitride, etc. Inorganic nitrides of the above; poorly soluble ionic crystals such as calcium fluoride, barium fluoride and barium sulfate; covalent bonds such as silicon and diamond; clays such as montmorillonite; Here, the inorganic oxide may be boehmite, zeolite, apatite, kaolin, mullite, spinel, olivine, mica, or other mineral resource-derived substances or artificial products thereof. In addition, the surface of a conductive material exemplified by metal, SnO ₂ , conductive oxide such as tin-indium oxide (ITO), carbonaceous material such as carbon black, graphite, etc., is a material having electrical insulation ( For example, it may be a filler that is electrically insulated by coating with the above-described inorganic oxide or the like. Of these, alumina, silica and boehmite are particularly preferably used.

  In addition, as the organic filler, various crosslinked polymers such as crosslinked polymethyl methacrylate, crosslinked polystyrene, crosslinked polydivinylbenzene, crosslinked styrene-divinylbenzene copolymer, polyimide, melamine resin, phenol resin, benzoguanamine-formaldehyde condensate, etc. Fine particles; heat-resistant polymer fine particles such as polysulfone, polyacrylonitrile, polyaramid, polyacetal, and thermoplastic polyimide; In addition, the organic resin (polymer) constituting these organic fine particles is a mixture, modified body, derivative, or copolymer (random copolymer, alternating copolymer, block copolymer, graft copolymer) of the above exemplified materials. Polymer) or a crosslinked product (in the case of the above-mentioned heat-resistant polymer).

  As the form of the filler, for example, it may have a shape close to a sphere, or may have a plate shape, but from the viewpoint of short circuit prevention, plate-like particles and primary particles are aggregated. It is preferable that the particles have a secondary particle structure. For example, the filler acts as a skeleton of the separator in the separator and can exhibit a function of suppressing the shrinkage of the entire separator when the temperature of the battery becomes high. However, the filler is plate-shaped. In the case where the primary particles have a secondary particle structure in which primary particles are aggregated, the action as the skeleton of the separator is improved. In addition, by using a secondary particle structure in which plate-like particles or primary particles are aggregated as a filler, the path between the positive electrode and the negative electrode in the separator, that is, the so-called curvature increases, so even if dendrite is generated, dendrite It becomes difficult to reach the positive electrode from the negative electrode, and the reliability with respect to the dendrite short can also be improved. Typical examples of the plate-like particles and secondary particles include plate-like alumina, plate-like boehmite, secondary particle-like alumina, and secondary particle-like boehmite.

  The average particle size of the filler (the average particle size determined by the above measurement method for the filler having a secondary particle structure) is, for example, preferably 0.01 μm or more, more preferably 0.1 μm or more. Moreover, it is preferable that it is 15 micrometers or less, and it is more preferable that it is 5 micrometers or less.

  When the filler is a plate-like particle, the aspect ratio (ratio between the maximum length in the plate-like particle and the thickness of the plate-like particle) is preferably 5 or more, more preferably 10 or more, preferably Is 100 or less, more preferably 50 or less. The aspect ratio of the plate-like particles can be obtained, for example, by analyzing an image taken with a scanning electron microscope (SEM).

  The amount of filler in the separator of the present invention is the total volume of the constituent components in the separator before being immersed in the non-aqueous electrolyte (however, when a porous substrate described later is used, In the whole volume, the same applies to the amount of filler in the separator.) It is preferably 10% by volume or more, and more preferably 20% by volume or more. The filler content is preferably 60% by volume or less, and more preferably 50% by volume or less. If the amount of filler in the separator is too small, the effect of increasing the strength of the separator and preventing short-circuiting is reduced, and if too large, the separator becomes brittle, for example, a positive electrode and a separator are stacked to form a wound electrode body When doing so, there is a risk of problems such as cracking in the separator.

  In the separator of the present invention, for example, a porous substrate can be used in order to improve the strength and enhance the handling property. Examples of the porous substrate include woven fabric, nonwoven fabric, and microporous membrane, and one or more of these can be used.

  Specific constituent materials of the porous substrate include, for example, cellulose and modified products thereof [carboxymethylcellulose (CMC), hydroxypropylcellulose (HPC), etc.], polyolefin [polypropylene (PP), propylene copolymer, etc.] , Polyester [polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), etc.], polyacrylonitrile (PAN), polyaramid, polyamideimide, polyimide and other resins; glass, alumina, zirconia, silica, etc. Inorganic oxides; and the like, and two or more of these constituent materials may be used in combination. These constituent materials may contain various known additives (for example, an antioxidant in the case of a resin) as necessary.

  In order to give the separator of the present invention a so-called shutdown function that blocks the pores of the separator and inhibits the movement of ions when the temperature of the battery rises, in addition to the above-mentioned various constituent materials, a thermoplastic resin having a melting point of 80 to 140 ° C. [Hereinafter referred to as “resin (C)”. ] Can also be contained. The resin (C) is not particularly limited as long as it has a melting point of 80 to 140 ° C., is electrochemically stable, and is stable to a nonaqueous electrolytic solution, but the melting point may be 100 ° C. or higher. More preferably, it is more preferably 125 ° C. or lower.

  In addition, melting | fusing point of resin (C) means the melting temperature measured using DSC according to the prescription | regulation of JISK7121.

  Specific examples of the resin (C) include polyolefins such as polyethylene (PE), polypropylene (PP), chlorinated polypropylene, and polycycloolefin; ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer, And thermoplastic resins such as copolymer polyolefins such as ethylene-methyl methacrylate copolymer. The copolymerized polyolefin is a so-called hot melt resin, and preferably has a unit ratio derived from ethylene of 65 mol% or more. Among the thermoplastic resins, polyethylene, chlorinated polypropylene, or EVA having a unit ratio derived from ethylene of 65 mol% or more is preferable.

  The resin (C) may be contained in the separator in the form of fine particles, in addition to the above-mentioned various constituent materials, or may be used as composite fine particles combined with the resin (B) or filler. As the form of the composite fine particles, a core-shell type in which the resin (B) is the core and the resin (C) is the shell, a core-shell type in which the resin (C) is the core and the resin (B) is the shell, and the filler is the core and the resin A core-shell type such as a core-shell type with (C) as the shell is desirable. The core-shell fine particles having the resin (C) as a core and the resin (B) as a shell are allowed to coexist with the resin (C) during the dispersion polymerization for synthesizing the resin (B). It can be produced by polymerizing the resin (B). Core-shell fine particles having the resin (B) as a core and the resin (C) as a shell are prepared by a wet composite method using a homogenizer or the like by placing the resin (C) in a dispersion of the resin (B). can do. Core-shell type fine particles with a filler as a core and a resin (C) as a shell are produced by the above-mentioned wet compounding method or dry compounding method using mechanofusion (trade name: manufactured by Hosokawa Micron Corporation). Is possible.

  When the resin (C) is used as a single fine particle or the above-described core-shell fine particle, the average particle size is preferably 0.1 μm or more, more preferably 0.3 μm or more, Moreover, it is preferable that it is 10 micrometers or less, and it is more preferable that it is 5 micrometers or less.

  The resin (C) may be introduced into the separator as a constituent material of the porous substrate. Furthermore, as will be described later, it is also possible to make the battery contain a porous layer made of resin (C) separately from the separator to form a shutdown layer.

  The thickness of the separator is preferably 50 μm or less, and more preferably 30 μm or less, from the viewpoint of further reducing the volume occupied by the separator when the battery is used and increasing the energy density of the battery. Further, from the viewpoint of reliably separating the positive electrode and the negative electrode and better preventing a short circuit, the thickness of the separator is preferably 1 μm or more, and more preferably 5 μm or more.

  As a manufacturing method of the separator of the present invention, for example, the following method (a) or (b) can be employed. In the production method (a), a resin (A), a resin (B), and, if necessary, a composition containing a filler and a resin (C) (a liquid composition such as a slurry) is applied to the porous substrate. In this method, the separator is dried at a predetermined temperature.

  The composition for forming a separator contains a resin (A), a resin (B), and, if necessary, a filler and a resin (C), and these are dispersed in a solvent (including a dispersion medium; the same applies hereinafter). It is a thing. The resin (A) can also be dissolved in a solvent. The solvent used in the composition for forming a separator may be any one that can uniformly disperse the resin (B), filler, resin (C), etc., and can uniformly dissolve or disperse the resin (A). Common organic solvents such as aromatic hydrocarbons such as toluene, furans such as tetrahydrofuran, and ketones such as methyl ethyl ketone and methyl isobutyl ketone are preferably used. In addition, for the purpose of controlling the interfacial tension, alcohols (ethylene glycol, propylene glycol, etc.) or various propylene oxide glycol ethers such as monomethyl acetate may be appropriately added to these solvents. Also, water can be used as the solvent. Also at this time, alcohols (methyl alcohol, ethyl alcohol, isopropyl alcohol, ethylene glycol, etc.) can be appropriately added to control the interfacial tension.

  The composition for forming a separator preferably has a solid content including the resin (A), the resin (B), the filler, and the resin (C) of, for example, 10 to 80% by mass.

  When the opening diameter of the pores of the porous substrate is relatively large, for example, 5 μm or more, this tends to cause a short circuit of the nonaqueous electrolyte battery. Therefore, in this case, it is preferable to have a structure in which all or part of the constituent components of the separator such as the resin (A), the resin (B), the filler, and the resin (C) are present in the voids of the porous substrate. . In order to make the constituent components exist in the voids of the porous substrate, for example, after applying the separator-forming composition containing these to the porous substrate, passing a certain gap, and removing the excess composition, A process such as drying may be used.

  Moreover, in the separator, when the plate-like particles are used as the filler as described above, the action can be more effectively exhibited by enhancing the orientation of the filler. In order to increase the orientation of the plate-like filler, a separator forming composition containing the plate-like filler is applied to a porous substrate and impregnated, and then a shear or magnetic field is applied to the composition. Use it. For example, as described above, after the separator-forming composition containing the plate-like filler is applied to the porous substrate, the composition can be shared by passing through a certain gap.

  Further, in order to more effectively exhibit the action of the other components constituting the filler and the separator, these components are unevenly distributed, and the components are gathered in layers in parallel or substantially parallel to the surface of the separator. It is good.

  The separator production method (b) is a method for applying a separator-forming composition on a substrate such as a film or a metal foil, drying it at a predetermined temperature, and then peeling it from the substrate as necessary. . In the case of this production method (b), as the film, for example, a microporous film mainly composed of the resin (C) can be used (in this case, a layer formed from the separator-forming composition, a microporous film, Are integrated to form a separator, so there is no need to peel off the layer.)

  As a method for applying the separator-forming composition, a method of applying to the substrate surface using a conventionally known coating apparatus such as a blade coater, a roll coater, a die coater, or a spray coater, and then drying is adopted. Is desirable.

  Moreover, it is good also as a structure which formed the separator on the surface of the positive electrode or negative electrode which comprises a nonaqueous electrolyte battery, and integrated the separator and the electrode with the manufacturing method (b).

  Even when the manufacturing method (a) is adopted, the separator may be integrated with at least one of the positive electrode and the negative electrode. In order to integrate the separator manufactured by the manufacturing method (a) with the electrode, for example, a method in which the separator and the electrode are overlapped and roll pressed can be employed.

  The nonaqueous electrolyte battery (nonaqueous electrolyte secondary battery) of the present invention is configured using the separator of the present invention. That is, in the non-aqueous electrolyte battery of the present invention, after assembling the non-aqueous electrolyte battery using the separator, an external stimulus such as heat is applied to crosslink the resin (B) eluted from the separator into the non-aqueous electrolyte. It has the gel electrolyte formed.

  In addition, as a non-aqueous electrolyte battery of this invention, what has the aspect of following (I) or (II) is mentioned, for example. The mode of (I) is a battery in which the separator of the present invention as an independent film is interposed between the positive and negative electrodes, and the resin (B) is dissolved in a non-aqueous electrolyte and gelled to form a gel electrolyte. . In the embodiment (II), the separator of the present invention is integrally formed on at least one surface of the positive electrode and the negative electrode, and the positive electrode and the negative electrode face each other with the separator interposed therebetween. Is a battery that dissolves in a non-aqueous electrolyte and gels to form a gel electrolyte.

  As the positive electrode of the nonaqueous electrolyte battery of the present invention, a positive electrode used in a conventionally known nonaqueous electrolyte battery, that is, a positive electrode capable of occluding and releasing lithium ions can be used.

Examples of the positive electrode active material that can be used for the positive electrode include LiCoO ₂ , LiNiO ₂ , chalcogenite-based oxides such as LiNi _x Co _(1-x) O _{2 in} which a part of Ni in LiNiO ₂ is substituted with Co, LiMn ₂ O Spinel oxides such as _4, layered MnNi compounds such as LiNi _{(1-x) / 2} Mn _{(1-x) / 2} Co _x O ₂ , and olivine oxidations such as LiMPO ₄ (M: Co, Ni, Mn, Fe) Examples thereof include inorganic oxides that can occlude and release lithium ions, which are used in ordinary nonaqueous electrolyte batteries.

  These active materials are mixed with a conductive auxiliary agent for imparting conductivity and a binder for imparting binding properties, if necessary, and a dispersion medium [N-methyl-2-pyrrolidone (NMP), water, toluene Etc.] are used to form a slurry-like positive electrode mixture-containing composition, and this composition is applied to the surface of the current collector, dried, and then pressed to form a positive electrode mixture layer on the surface of the current collector. can do. As the conductive aid, carbon materials such as acetylene black (AB), ketjen black (KB), graphite, and amorphous carbon may be used alone or in combination of two or more. May be used in combination. In addition, binders that are usually used, for example, fluorine resin materials such as PVDF and polytetrafluoroethylene (PTFE); rubber-based materials such as SBR; May be used in combination. In the positive electrode mixture layer, for example, it is desirable that the amount of active material is 50 to 99% by mass, the amount of conductive auxiliary agent is 0.5 to 40% by mass, and the amount of binder is 0.5 to 20% by mass. The thickness of the positive electrode mixture layer is desirably, for example, 10 to 100 μm per one side of the current collector.

  As the positive electrode current collector, for example, an aluminum foil, a punching metal, a net, an expanded metal, or the like can be used. However, an aluminum foil having a thickness of 10 μm to 30 μm is preferably used. If the current collector is too thin, its strength becomes too weak and difficult to handle, and if it is too thick, the volume ratio occupied by the current collector in the battery increases, and the energy density of the battery decreases.

  As the negative electrode related to the nonaqueous electrolyte battery of the present invention, a negative electrode used in a conventionally known nonaqueous electrolyte battery, that is, a negative electrode capable of occluding and releasing lithium ions can be used.

As the negative electrode active material, it is possible to use at least one material among a material capable of inserting and extracting lithium ions, lithium metal, a lithium alloy, or a metal that can be alloyed with lithium. Examples of the lithium alloy include a lithium-aluminum alloy. Examples of the metal that can be alloyed with lithium include Sn and Si. Other materials that can occlude and release lithium ions include carbon-based materials such as amorphous carbon, artificial graphite, natural graphite, fullerene, and carbon nanotubes; titanium such as Li ₄ Ti ₅ O ₁₂ and Li ₂ Ti ₃ O _7. Lithium acid; and the like.

For example, in the case of lithium metal, a lithium alloy, or a metal that can be alloyed with lithium, a thin film (foil, etc.) composed of the metal is crimped to the current collector as an active material-containing layer, or sputtering, vapor deposition, plating, etc. A negative electrode can be obtained by forming a layer (active material containing layer) containing them on the current collector surface by a method. In the case of other negative electrode active materials, for example, it is dispersed in a dispersion medium (NMP, water, toluene, etc.) together with a conductive additive or a binder as necessary to obtain a slurry-like negative electrode mixture-containing composition. Is applied to the surface of the current collector, dried, and further pressed to obtain a negative electrode in which an active material-containing layer (negative electrode mixture layer) is formed on the current collector surface. As a conductive support agent, AB, KB, amorphous carbon etc. are mentioned, for example, These may be used individually by 1 type and may use 2 or more types together. Moreover, as a binder, PVDF, PTFE, SBR, CMC, hydroxypropyl cellulose etc. can be illustrated, for example, These may be used individually by 1 type and may use 2 or more types together.

  When a negative electrode mixture layer is formed using a conductive additive or a binder, in the negative electrode mixture layer, for example, the active material amount is 50 to 99% by mass, the conductive auxiliary agent amount is 0 to 40% by mass, and the binder amount. Is desirably 0.5 to 20% by mass. The thickness of the active material-containing layer such as the negative electrode mixture layer is preferably 30 to 150 μm per side of the current collector, for example.

  As the current collector for the negative electrode, a foil made of copper or nickel, a punching metal, a net, an expanded metal, or the like can be used, but a copper foil is usually used. The thickness of the negative electrode current collector is desirably 6 to 30 μm. If the current collector is too thin, its strength becomes too weak and difficult to handle, and if it is too thick, the volume ratio occupied by the current collector in the battery increases, and the energy density of the battery decreases.

  When assembling the nonaqueous electrolyte battery of the present invention, the positive electrode and the negative electrode are laminated via a separator formed on the electrode surface, or the positive electrode and the negative electrode are laminated via the separator. A laminated electrode body or a further wound electrode body is obtained. Such an electrode body is inserted into an outer can of a rectangular tube shape or a cylindrical shape made of iron, stainless steel, aluminum, or the like, or a soft package using a metal-deposited laminated film as an outer material, Sealing after injecting the non-aqueous electrolyte, and then applying an external stimulus such as heat to crosslink the resin (B) eluted from the separator into the non-aqueous electrolyte to form a gel electrolyte, A non-aqueous electrolyte battery can be obtained.

As the non-aqueous electrolyte, for example, a solution obtained by dissolving a lithium salt used in a conventionally known non-aqueous electrolyte battery in an organic solvent is used. The lithium salt is not particularly limited as long as it dissociates in a solvent to form Li ⁺ ions and does not cause a side reaction such as decomposition in a voltage range used as a battery. Specifically, for example, inorganic compounds such as LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiClO ₄ ; LiN (SO ₂ CF ₃ ) ₂ , LiN (SO ₂ C ₂ F ₅ ) ₂ , LiN (SO ₂ CF ₃ ) _{(SO 2 O 4 F 9)} , LiC (SO 2 CF 2) 3, LiC (SO 2 C 2 F 5) 2, LiPF 6-n (C 2 F 5) n (n is an integer from 1 to 6), Organic compounds such as LiSO ₃ CF ₃ , LiSO ₃ C ₂ F ₅ , LiSO ₃ O ₄ F _8, etc. can be used. Incidentally, inorganic anions such as LiPF ₆ or LiBF ₄ functions as a cationic initiator of the resin (A). Therefore, in order to allow the crosslinking of the resin (A) to proceed smoothly, it is preferable that the non-aqueous electrolyte contains LiPF ₆ or LiBF ₄ .

  The organic solvent used for the non-aqueous electrolyte is not particularly limited as long as it dissolves the lithium salt and does not cause a side reaction such as decomposition in a voltage range used as a battery. For example, cyclic carbonates such as ethylene carbonate, propylene carbonate, butylene carbonate, vinylene carbonate; chain carbonates such as dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate; cyclic esters such as γ-butyrolactone; dimethoxyethane, diglyme, triglyme, tetraglyme, etc. Chain ethers; cyclic ethers such as dioxane, tetrahydrofuran, 2-methyltetrahydrofuran; nitriles such as acetonitrile, propionitrile, methoxypropionitrile; and the like. These may be used alone or in combination. You may use the above together. In order to obtain a battery with better characteristics, it is desirable to use a combination that can obtain high conductivity, such as a mixed solvent of ethylene carbonate and chain carbonate. In addition, vinylene carbonates, 1,3-propane sultone, diphenyl disulfide, cyclohexylbenzene, biphenyl, and fluorobenzene are used for the purpose of improving safety, charge / discharge cycleability, and high-temperature storage properties of these non-aqueous electrolytes. An additive such as t-butylbenzene may be added as appropriate.

  The lithium salt concentration in the non-aqueous electrolyte is preferably 0.8 to 1.5 mol / l, for example.

  Moreover, when using resin (C) in order to provide a shutdown characteristic to a battery, a separator is formed using the composition for separator formation which also contains resin (C) as mentioned above, and resin (C) is a separator. Besides the separator, a porous layer such as a microporous film mainly containing the resin (C) can be disposed between the positive and negative electrodes together with the separator, in addition to the separator. In this case, the porous layer may be an independent film or may be integrated with the electrode.

  As the independent membrane of the resin (C), for example, a porous membrane composed of the above-mentioned exemplified thermoplastic resin used in a conventionally known non-aqueous electrolyte battery or the like, that is, a solvent extraction method, a dry type or An ion-permeable porous membrane (microporous membrane) produced by a wet stretching method or the like can be used. In addition, a porous layer is formed by using an emulsion in which fine particles of resin (C) are dispersed in a suitable dispersion medium, adding an organic binder as necessary, applying to the separator surface or electrode surface, and drying. You can also In addition, the various resin illustrated as resin (A) can be used for the organic binder in this case, for example.

  In order to crosslink the resin (B) eluted from the separator into the non-aqueous electrolyte, it is preferable to perform a heat treatment as described above. As the heat treatment conditions therefor, for example, the resin represented by the general formula (1) Is preferably used as the resin (B), the temperature is preferably 50 to 80 ° C. and the time is preferably 30 minutes to 5 hours. Moreover, as a method of heat processing, the method of leaving still in a thermostat can be employ | adopted, for example.

  Since the non-aqueous electrolyte battery of the present invention is excellent in battery characteristics (particularly charge / discharge cycle characteristics) and safety, various electronic devices such as mobile terminal devices such as mobile phones, notebook personal computers, and PDAs are used. It can be suitably used as a power source.

  Hereinafter, the present invention will be described in detail based on examples. However, the following examples do not limit the present invention.

Example 1
<Preparation of positive electrode>
LiCoO _{2 as a} positive electrode active material: 80 parts by mass, acetylene black as a conductive auxiliary agent: 10 parts by mass, and PVDF as a binder: 10 parts by mass are mixed so that NMP is a uniform dispersion medium. A positive electrode mixture-containing paste was prepared. This paste was intermittently applied to both sides of an aluminum foil having a thickness of 15 μm and a width of 800 mm as a current collector so that the coating length was 280 mm on the front surface and 210 mm on the back surface, dried, and then subjected to a calendar treatment to obtain a total thickness. The thickness of the positive electrode mixture layer was adjusted so as to be 150 μm, and the positive electrode was obtained by slitting so that the width was 43 mm. The exposed portion of the positive electrode current collector was tabbed.

<Production of negative electrode>
A negative electrode mixture-containing paste was prepared by mixing 95 parts by mass of graphite as a negative electrode active material and 5 parts by mass of PVDF as a binder so as to be uniform using NMP as a solvent. This negative electrode mixture-containing paste was intermittently applied on both sides of a 10 μm-thick current collector made of copper foil so that the coating length was 290 mm on the front surface and 230 mm on the back surface, dried, and then subjected to calendering to obtain a total thickness. The thickness of the negative electrode mixture layer was adjusted so as to be 142 μm, and the negative electrode mixture layer was cut to have a width of 45 mm to produce a negative electrode having a length of 300 mm and a width of 45 mm. Further, a tab was welded to the exposed portion of the copper foil of the negative electrode to form a lead portion.

<Preparation of resin (B) fine particles>
Water: 300 g, polyvinylpyrrolidone (PVP): 3 g as a stabilizer, sodium dodecylbenzenesulfonate (SDS): 0.7 g as a surfactant, methyl methacrylate (MMA): 70 g as a monomer, in the general formula (5) indicated, with ^{R 5} is a methyl group, a monomer having a carbon number of 2 to ^{R 6:} 30 g, potassium persulfate (KPK) as a polymerization initiator: were added 10g. In addition, the ratio of MMA in all monomers is 80 mol%. While this dispersion was stirred in a nitrogen atmosphere at a speed of 300 rpm at 65 ° C., dispersion polymerization was performed for 5 hours to obtain an aqueous dispersion of resin (B) fine particles. A part of the obtained fine particles was vacuum-dried at 60 ° C. for 15 hours, and the average particle size was 0.4 μm. A self-crosslinking acrylic resin emulsion (Tg: −30 ° C., solid content ratio) obtained by polymerization of a monomer mainly composed of butyl acrylate as the resin (A) in the aqueous dispersion of the resin (B) fine particles. (45% by mass) 200 g was added and stirred until uniform to obtain a separator-forming composition.

  Only the emulsion of the resin (A) was cast on a polytetrafluoroethylene plate to produce a film having a thickness of 0.5 mm. When this film was measured for a decrease in heating weight in a nitrogen atmosphere using a thermogravimetric balance “TGA-80 type” manufactured by Rigaku, the temperature at which the weight decrease by 1% was 260 ° C. The film was placed in a sealed container filled with a non-aqueous electrolyte (non-aqueous electrolyte having the same composition as that used in the production of the battery described later in this example) and held at 150 ° C. for 1 hour. When cooled to room temperature and taken out, no change in shape was observed. From these results, it was found that the resin (A) had a heat resistant temperature of 150 ° C. or higher.

<Preparation of separator>
The separator-forming composition is applied to the surface of a microporous film (thickness: 12 μm, porosity: 40%) made of PE (resin melting point: 135 ° C.) as the resin (C) using a die coater, and dried. Formed. The thickness of the separator obtained was 16 μm, and the constituent components of the separator (PE microporous material) determined with the specific gravity of the resin (A) being 1.2 g / cm ³ and the specific gravity of the resin (B) being 1.2 g / cm ^3. The amount of the resin (B) in the entire volume of the whole volume (excluding the membrane) was 51% by volume.

<Battery assembly>
The positive electrode, the negative electrode, and the separator were superposed and wound in a spiral shape to obtain a wound electrode body. The wound electrode body is crushed into a flat shape and inserted into a laminate film packaging material, and 1.2 mol of LiPF ₆ is added to a non-aqueous electrolyte (a solvent in which ethylene carbonate and ethyl methyl carbonate are mixed at a volume ratio of 1: 2). Solution was dissolved at a concentration of / l) and vacuum sealed to produce a laminate battery (non-aqueous electrolyte battery). The obtained laminated battery was allowed to stand at room temperature for 24 hours, and then heated at 60 ° C. for 5 hours to gel the non-aqueous electrolyte to obtain a laminated battery having a gel-like non-aqueous electrolyte.

Example 2
<Preparation of resin (B) fine particles>
Water: 300 g, PVP: 3 g as a stabilizer, SDS: 0.7 g as a surfactant, methyl methacrylate (MMA): 70 g as a monomer, represented by the general formula (6), and R ⁷ is a hydrogen atom monomer: 30 g and 10 g of KPK as a polymerization initiator were added. In addition, the ratio of MMA in all monomers is 80 mol%. While this dispersion was stirred in a nitrogen atmosphere at a speed of 300 rpm at 65 ° C., dispersion polymerization was performed for 5 hours to obtain an aqueous dispersion of resin (B) fine particles. A part of the obtained fine particles was vacuum-dried at 60 ° C. for 15 hours, and the average particle diameter measured was 0.5 μm. In this aqueous dispersion of resin (B) fine particles, 250 g of SBR latex (Tg: −20 ° C., solid content ratio 40% by mass) as resin (A) and boehmite (secondary particles, average particle size 2 μm) as filler are used. 500 g was added and stirred until uniform to prepare a separator-forming composition.

<Preparation of separator>
A PET non-woven fabric (thickness 12 μm, basis weight 10 g / m ² ) was used as a porous substrate, and the separator-forming composition was applied to the porous substrate using a dip coater and dried to form a separator. The thickness of the obtained separator is 16 μm, the specific gravity of the resin (A) is 1.0 g / cm ³ , the specific gravity of the resin (B) is 1.2 g / cm ³ , and the specific gravity of the filler is 3.0 g / cm ^3. The amount of the resin (B) in the total volume of the constituent components of the separator (excluding the nonwoven fabric made of PET) determined as was 24% by volume, and the amount of filler was 48% by volume.

<Battery assembly>
A laminated battery having a gel electrolyte was produced in the same manner as in Example 1 except that the separator was used.

Example 3
As resin (C), PE emulsion (melting point 125 ° C., solid content ratio 40% by mass) was applied to both sides of the same negative electrode as prepared in Example 1 so that the thickness after drying was 5 μm per side. And dried to form a layer of resin (C). A laminated battery having a gel electrolyte was produced in the same manner as in Example 2 except that this negative electrode was used.

Example 4
The same composition for forming a separator as that prepared in Example 2 was applied to both sides of the same negative electrode as that prepared in Example 1 so that the thickness after drying was 10 μm per side and dried.

  The negative electrode and the same positive electrode as that prepared in Example 1 were spirally wound through the same PET nonwoven fabric as used in Example 2 to obtain a wound electrode body. A laminated battery having a gel electrolyte was produced in the same manner as in Example 1 except that this wound electrode body was used.

Example 5
The same PE emulsion as used in Example 3 was applied to the same PET nonwoven fabric used in Example 2 using a dip coater in the same manner as in Example 2, and a resin (C) having a thickness of 14 μm. A porous layer containing was prepared. A laminated battery having a gel electrolyte was produced in the same manner as in Example 4 except that this porous layer was used in place of the PET nonwoven fabric.

Comparative Example 1
A laminated battery having a gel electrolyte was produced in the same manner as in Example 1 except that a PE microporous membrane (thickness 20 μm, porosity 40%) was used as the separator. In addition, since the battery of Comparative Example 1 does not contain a material for forming the gel electrolyte, heat treatment for gelation is not necessary, but the same heat treatment as in Example 1 was performed for comparison. .

  The batteries of Examples 1 to 5 and Comparative Example 1 were subjected to the following electrochemical evaluation and safety evaluation. The results are shown in Table 1.

[Electrochemical evaluation]
Each battery was charged at a constant current of 0.2 C until it reached 4.2 V, and subsequently charged at a constant voltage of 4.2 V. The total time from the start of constant current charging to the end of constant voltage charging was 7 hours. Each battery after charge was initialized by discharging at 0.2 C until the voltage changed from 4.2 V to 3.0 V.

  About each battery after the said initialization, it charged until it became 4.2V with the constant current of 0.5C, and it charged with the constant voltage of 4.2V continuously. The total time from the start of constant current charging to the end of constant voltage charging was 3 hours. And each battery after charge was discharged at 0.5 C from 4.2 V to 3.0 V. This charging / discharging operation was defined as one cycle, and 100 cycles of charging / discharging were performed. And the discharge capacity of the 1st cycle and the discharge capacity of the 100th cycle were measured, and the discharge capacity ratio (%) of the 100th cycle to the discharge capacity of the 1st cycle was evaluated as a capacity maintenance rate. That is, the higher the capacity retention rate, the better the charge / discharge cycle characteristics of the battery.

[Safety evaluation]
Each battery after initialization under the above conditions (battery different from that subjected to the electrochemical evaluation) was charged to 4.2 V at a constant current of 0.5 C, and subsequently 4.2 V The battery was charged at a constant voltage. The total time from the start of constant current charging to the end of constant voltage charging was 3 hours. Each battery in this charged state was subjected to a high temperature holding test for 30 minutes in an environment of 150 ° C., and safety was evaluated based on the presence or absence of a short circuit.

  As shown in Table 1, in the batteries of Examples 1 to 5, the capacity retention rate is high, no short circuit is observed even during the high temperature holding test, and the battery characteristics (charge / discharge cycle characteristics) and safety are excellent. Further, since the resin (B) can be easily introduced into the battery, the formation of the gel electrolyte is easy and the productivity is good. On the other hand, in the battery of Comparative Example 1, a short circuit occurred during the high temperature holding test.

Claims (11)

A resin (A) that is stable at room temperature with respect to the non-aqueous electrolyte and has a heat-resistant temperature of 150 ° C. or higher;
Contain reactive groups to form a crosslinked structure, and then dissolved in the non-aqueous electrolytic solution have the resin (B) that form a vacancy,
The resin (B), a non-aqueous electrolyte battery separator characterized by Oh Rukoto in particulate acrylic resin or a methacrylic resin containing an epoxy group or an oxetane group. The separator for a nonaqueous electrolyte battery according to claim 1, wherein the content of the resin (B) is 10 to 70% by volume in the total volume of the constituent components of the separator. The separator for a nonaqueous electrolyte battery according to claim 1 or 2 , wherein the resin (B) has an average particle size of 0.1 to 0.3 µm . Content of resin (A) is 10-50 volume% in the whole volume of the structural component of a separator, The separator for nonaqueous electrolyte batteries in any one of Claims 1-3.   The separator for nonaqueous electrolyte batteries according to any one of claims 1 to 4, wherein the resin (A) comprises a resin having a glass transition temperature of room temperature or lower.   The separator for nonaqueous electrolyte batteries according to claim 1, further comprising an inorganic filler.   The separator for nonaqueous electrolyte batteries according to claim 1, further comprising a porous substrate. The separator for a nonaqueous electrolyte battery according to claim 7 , wherein the porous substrate is a woven fabric, a nonwoven fabric or a microporous membrane. A non-aqueous electrolyte battery having at least a negative electrode capable of occluding and releasing lithium ions, a positive electrode capable of occluding and releasing lithium ions, a separator and a non-aqueous electrolyte,
A nonaqueous electrolyte battery using the separator for a nonaqueous electrolyte battery according to claim 1 as the separator. The nonaqueous electrolyte battery according to claim 9, wherein the separator-derived resin (B) forms a cross-linked structure to constitute a gel-like nonaqueous electrolyte together with the nonaqueous electrolytic solution . The nonaqueous electrolyte battery according to claim 9 or 10, wherein the separator is integrated with at least one of the positive electrode and the negative electrode.