WO2020091025A1 - Batterie secondaire à électrolyte non aqueux - Google Patents

Batterie secondaire à électrolyte non aqueux Download PDF

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Publication number
WO2020091025A1
WO2020091025A1 PCT/JP2019/042959 JP2019042959W WO2020091025A1 WO 2020091025 A1 WO2020091025 A1 WO 2020091025A1 JP 2019042959 W JP2019042959 W JP 2019042959W WO 2020091025 A1 WO2020091025 A1 WO 2020091025A1
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Prior art keywords
aqueous electrolyte
secondary battery
electrolyte secondary
porous layer
resin
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PCT/JP2019/042959
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English (en)
Japanese (ja)
Inventor
栄子 柏崎
孝輔 倉金
一郎 有瀬
村上　力
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住友化学株式会社
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Publication of WO2020091025A1 publication Critical patent/WO2020091025A1/fr

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/443—Particulate material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—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
    • H01M10/0566—Liquid materials
    • H01M10/0567—Liquid materials characterised by the additives
    • 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
    • H01M10/0566—Liquid materials
    • H01M10/0569—Liquid materials characterised by the solvents
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a non-aqueous electrolyte secondary battery.
  • Non-aqueous electrolyte secondary batteries such as lithium secondary batteries are currently widely used as batteries for devices such as personal computers, mobile phones and personal digital assistants.
  • non-aqueous electrolyte secondary battery for example, a non-aqueous electrolyte secondary battery including a battery separator formed of a porous layer containing boehmite (plate-like particles) as fine particles as described in Patent Document 1 It has been known.
  • the present invention has been made in view of the above problems, and an object thereof is to realize a non-aqueous electrolyte secondary battery having an excellent charge capacity after high rate discharge.
  • a non-aqueous electrolyte secondary battery includes a porous layer containing an inorganic filler and a resin, a non-aqueous electrolyte, a positive electrode and a negative electrode,
  • the porous layer has a value represented by the following formula (1) in the range of 0.10 to 0.42,
  • T represents a distance to a critical load in a scratch test under a constant load of 0.1 N in TD
  • M represents a scratch test under a constant load of 0.1 N in MD.
  • the non-aqueous electrolyte contains 0.5 ppm or more and 300 ppm or less of an additive having an ionic conductivity reduction rate L represented by the following formula (A) of 1.0% or more and 6.0% or less.
  • L (LA-LB) / LA ... (A)
  • LA was prepared by dissolving LiPF 6 in a mixed solvent containing ethylene carbonate, ethylmethyl carbonate and diethyl carbonate in a volume ratio of 3: 5: 2 such that the concentration thereof was 1 mol / L.
  • the non-aqueous electrolyte secondary battery according to Aspect 2 of the present invention is the same as in Aspect 1, except that the porous layer is laminated on one side or both sides of the polyolefin porous film.
  • the porous layer has a polyolefin, a (meth) acrylate resin, a fluorine-containing resin, a polyamide resin, a polyester resin. It includes a resin selected from the group consisting of resins and water-soluble polymers.
  • the polyamide resin is an aramid resin.
  • the nonaqueous electrolyte secondary battery according to Aspect 5 of the present invention is the nonaqueous electrolyte secondary battery according to any one of Aspects 1 to 4, wherein the nonaqueous electrolyte solution contains an electrolyte containing lithium.
  • the non-aqueous electrolyte secondary battery according to Aspect 6 of the present invention in any one of Aspects 1 to 5, the non-aqueous electrolyte contains an aprotic polar solvent.
  • non-aqueous electrolyte secondary battery having excellent 1C charge capacity after high-rate discharge (for example, 10C discharge).
  • FIG. 1 It is a schematic diagram showing the structure of the said porous layer when the orientation of an inorganic filler is large in the porous layer containing an inorganic filler (left figure), and when the orientation of an inorganic filler is small (right figure). It is a figure which shows the apparatus and its operation in a scratch test. It is the figure which showed the critical load and the distance to a critical load in the graph created from the result of the scratch test.
  • a non-aqueous electrolyte secondary battery includes a porous layer described below, a positive electrode, a negative electrode, and a non-aqueous electrolyte.
  • the non-aqueous electrolyte secondary battery according to the exemplary embodiment of the present invention may further include a polyolefin porous film described below.
  • the porous layer in one embodiment of the present invention is a porous layer containing an inorganic filler and a resin, and the value represented by the following formula (1) or (2) is 0.10 to 0.42. In range.
  • the porous layer may be disposed between the polyolefin porous film and at least one of the positive electrode and the negative electrode as a member constituting the non-aqueous electrolyte secondary battery.
  • the porous layer may be formed on one side or both sides of the polyolefin porous film.
  • the porous layer may be formed on the active material layer of at least one of the positive electrode and the negative electrode.
  • the porous layer may be arranged between the polyolefin porous film and at least one of the positive electrode and the negative electrode so as to be in contact with them.
  • the porous layer arranged between the polyolefin porous film and at least one of the positive electrode and the negative electrode may be one layer or two or more layers.
  • the porous layer is preferably an insulating porous layer containing a resin.
  • the porous layer is laminated on one side of the polyolefin porous film
  • the porous layer is preferably laminated on the surface of the polyolefin porous film facing the positive electrode. More preferably, the porous layer is laminated on the surface in contact with the positive electrode.
  • the ratio of the distance (T) to the critical load in TD and the distance (M) to the critical load in MD measured by the above scratch test is an index showing the orientation of the inorganic filler in the porous layer. ..
  • the values represented by the formulas (1) and (2) using the ratio of T and M are also simply referred to as formulas (1) and (2), respectively.
  • a schematic view of the state of the inorganic filler in the porous layer when the orientation is high, that is, anisotropic, and when the orientation is low, that is, isotropic is shown in FIG. ..
  • FIG. 1 is a schematic diagram showing the structure of the porous layer containing an inorganic filler, in which the orientation of the inorganic filler is large and exhibits anisotropy, and the right diagram of FIG. It is a schematic diagram showing the structure of the said porous layer in case the orientation of an inorganic filler is small and it shows isotropic property.
  • the porous layer in one embodiment of the present invention has a large number of pores inside and has a structure in which these pores are connected, and gas or liquid can pass from one surface to the other surface. It is a layer that became. Further, when the porous layer in one embodiment of the present invention is used as a member constituting a laminated separator for a non-aqueous electrolyte secondary battery, the porous layer is an outermost layer of the laminated separator and is in contact with an electrode. Can be a layer.
  • the resin contained in the porous layer in one embodiment of the present invention is preferably insoluble in the electrolytic solution of the battery and is electrochemically stable in the usage range of the battery.
  • the resin include polyolefins; (meth) acrylate resins; fluorine-containing resins; polyamide resins; polyimide resins; polyester resins; rubbers; melting points or glass transition temperatures of 180 ° C. or higher.
  • Resins water-soluble polymers; polycarbonates, polyacetals, polyether ether ketones and the like.
  • polyolefins polyolefins, polyester resins, (meth) acrylate resins, fluorine-containing resins, polyamide resins and water-soluble polymers are preferable.
  • polyethylene polyethylene, polypropylene, polybutene, ethylene-propylene copolymer and the like are preferable.
  • polyamide resin aramid resins such as aromatic polyamide and wholly aromatic polyamide are preferable.
  • the aramid resin examples include poly (paraphenylene terephthalamide), poly (metaphenylene isophthalamide), poly (parabenzamide), poly (metabenzamide), poly (4,4′-benzanilide terephthalate). Amide), poly (paraphenylene-4,4′-biphenylenedicarboxylic acid amide), poly (metaphenylene-4,4′-biphenylenedicarboxylic acid amide), poly (paraphenylene-2,6-naphthalenedicarboxylic acid amide), Poly (metaphenylene-2,6-naphthalenedicarboxylic acid amide), poly (2-chloroparaphenylene terephthalamide), paraphenylene terephthalamide / 2,6-dichloroparaphenylene terephthalamide copolymer, metaphenylene terephthalamide / 2 , 6-diclosure Paraphenylene terephthalamide copolymer and the like. Of these, poly (paraphenylene
  • polyethylene polyethylene, polypropylene, polybutene, ethylene-propylene copolymer and the like are preferable.
  • fluorine-containing resin examples include polyvinylidene fluoride (PVDF), polytetrafluoroethylene, vinylidene fluoride-hexafluoropropylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer Coalescence, vinylidene fluoride-tetrafluoroethylene copolymer, vinylidene fluoride-trifluoroethylene copolymer, vinylidene fluoride-trichloroethylene copolymer, vinylidene fluoride-vinyl fluoride copolymer, vinylidene fluoride-hexafluoro Examples thereof include propylene-tetrafluoroethylene copolymer, ethylene-tetrafluoroethylene copolymer and the like, and fluorine-containing rubber having a glass transition temperature of 23 ° C. or lower among the fluor
  • polyester resin aromatic polyester such as polyarylate and liquid crystal polyester are preferable.
  • Examples of rubbers include styrene-butadiene copolymer and its hydride, methacrylic acid ester copolymer, acrylonitrile-acrylic acid ester copolymer, styrene-acrylic acid ester copolymer, ethylene propylene rubber, polyvinyl acetate and the like. Can be mentioned.
  • Examples of the resin having a melting point or glass transition temperature of 180 ° C. or higher include polyphenylene ether, polysulfone, polyether sulfone, polyphenylene sulfide, polyetherimide, polyamideimide, and polyetheramide.
  • water-soluble polymers examples include polyvinyl alcohol, polyethylene glycol, cellulose ether, sodium alginate, polyacrylic acid, polyacrylamide, polymethacrylic acid and the like.
  • fluorine-containing resin examples include polyvinylidene fluoride (PVDF), polytetrafluoroethylene, vinylidene fluoride-hexafluoropropylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer Coalescence, vinylidene fluoride-tetrafluoroethylene copolymer, vinylidene fluoride-trifluoroethylene copolymer, vinylidene fluoride-trichloroethylene copolymer, vinylidene fluoride-vinyl fluoride copolymer, vinylidene fluoride-hexafluoro Among them, propylene-tetrafluoroethylene copolymer, ethylene-tetrafluoroethylene copolymer and the like, and fluorine-containing rubber having a glass transition temperature of 23 ° C. or lower among the
  • the resin contained in the porous layer according to the embodiment of the present invention may be one kind or a mixture of two or more kinds.
  • a fluorine-containing resin is preferable because it can be easily maintained.
  • the porous layer in one embodiment of the present invention contains an inorganic filler.
  • the lower limit of the content is preferably 50% by weight or more and 70% by weight or more with respect to the total weight of the filler and the resin constituting the porous layer according to one embodiment of the present invention. It is more preferable that the amount is 90% by weight or more.
  • the upper limit of the content of the inorganic filler in the porous layer according to one embodiment of the present invention is preferably 99% by weight or less, and more preferably 98% by weight or less.
  • the content of the filler is preferably 50% by weight or more from the viewpoint of heat resistance, and the content of the filler is preferably 99% by weight or less from the viewpoint of adhesion between the fillers.
  • the inorganic filler is not particularly limited as long as it is a filler that is stable in a non-aqueous electrolytic solution and is electrochemically stable. From the viewpoint of ensuring the safety of the battery, a filler having a heat resistant temperature of 150 ° C. or higher is preferable.
  • the inorganic filler is not particularly limited, but is usually an insulating filler.
  • the inorganic filler is preferably an inorganic material containing at least one metal element selected from the group consisting of aluminum element, zinc element, calcium element, zirconia element, silicon element, magnesium element, barium element, and boron element, It is preferably an inorganic substance containing an aluminum element. Further, the inorganic filler preferably contains an oxide of the metal element.
  • the inorganic filler titanium oxide, alumina (Al 2 O 3 ), zinc oxide (ZnO), calcium oxide (CaO), zirconia oxide (ZrO 2 ), silica, magnesia, barium oxide, boron oxide, Examples thereof include mica, wollastonite, attapulgite, and boehmite (alumina monohydrate).
  • the inorganic filler one kind of filler may be used alone, or two or more kinds of filler may be used in combination.
  • the inorganic filler in the porous layer in one embodiment of the present invention preferably contains alumina and a plate-like filler.
  • the plate-like filler include one or more fillers selected from the group consisting of zinc oxide (ZnO), mica, and boehmite among the metal oxides listed above.
  • the volume average particle size of the inorganic filler is preferably in the range of 0.01 ⁇ m to 11 ⁇ m from the viewpoint of ensuring good adhesiveness and slipperiness, and moldability of the laminate.
  • the lower limit value is more preferably 0.05 ⁇ m or more, further preferably 0.1 ⁇ m or more.
  • the upper limit is more preferably 10 ⁇ m or less, further preferably 5 ⁇ m or less, and particularly preferably 1 ⁇ m or less.
  • the shape of the inorganic filler is arbitrary and is not particularly limited.
  • the shape of the inorganic filler may be a particle shape, for example, a single particle such as a spherical shape; an elliptical shape; a plate shape; a rod shape; a scale shape; an irregular shape; a fibrous shape; a peanut shape and / or a tetrapot shape. Any of the heat-sealed shapes may be used. From the viewpoint of preventing a short circuit in the battery, the inorganic filler is preferably plate-like particles and / or non-aggregated primary particles.
  • the shape of the inorganic filler is such that the particles in the porous material are difficult to be packed in the closest packing, an indefinite shape; a fibrous shape; a single particle such as a peanut shape and / or a tetrapot shape.
  • the fused shape is preferable.
  • the shape of the inorganic filler is particularly preferably a shape in which single particles are heat-sealed, such as a peanut shape and / or a tetrapot shape.
  • the filler can improve slipperiness by forming fine irregularities on the surface of the porous layer.
  • the filler is a plate-like particle and / or a primary particle that is not aggregated, the unevenness formed on the surface of the porous layer by the filler becomes finer, and the adhesiveness between the porous layer and the electrode is further improved. It will be good.
  • the oxygen atom mass percentage of the metal oxide constituting the inorganic filler contained in the porous layer in one embodiment of the present invention is preferably 10% to 50%, more preferably 20% to 50%. preferable.
  • the affinity between the solvent or the dispersion medium in the coating liquid used in the method for producing a porous layer described later and the inorganic filler is preferably adjusted. It is possible to keep the distance between the above-mentioned inorganic fillers at an appropriate distance. As a result, the dispersibility of the coating liquid can be improved, and as a result, the above formulas (1) and (2) can be controlled within an appropriate specified range.
  • the porous layer in one embodiment of the present invention may contain other components than the above-mentioned inorganic filler and resin.
  • the other components include surfactants, waxes and binder resins.
  • the content of the other components is preferably 0% by weight to 50% by weight based on the weight of the entire porous layer.
  • the average thickness of the porous layer in one embodiment of the present invention is preferably in the range of 0.5 ⁇ m to 10 ⁇ m per one layer of the porous layer from the viewpoint of ensuring adhesiveness with the electrode and high energy density. More preferably, it is in the range of 1 ⁇ m to 5 ⁇ m.
  • the basis weight per unit area of the porous layer can be appropriately determined in consideration of the strength, film thickness, weight and handling property of the porous layer.
  • the basis weight per unit area of the porous layer is preferably 0.5 to 20 g / m 2 and more preferably 0.5 to 10 g / m 2 per porous layer.
  • the weight energy density and volume energy density of the non-aqueous electrolyte secondary battery can be increased.
  • the basis weight of the porous layer exceeds the above range, the non-aqueous electrolyte secondary battery tends to be heavy.
  • the porous layer in one embodiment of the present invention preferably has a sufficiently porous structure from the viewpoint of ion permeability. Specifically, the porosity is preferably in the range of 30% to 60%. Further, the porous layer in one embodiment of the present invention preferably has an average pore size in the range of 20 nm to 100 nm.
  • the value represented by the following formula (1) is preferably in the range of 0.10 to 0.42, and in the range of 0.10 to 0.40. It is more preferable to be present, and it is further preferable to be in the range of 0.10 to 0.30.
  • T represents a distance to a critical load in a scratch test under a constant load of 0.1 N in TD
  • M represents a scratch test under a constant load of 0.1 N in MD.
  • the value represented by the following formula (2) is preferably in the range of 0.10 to 0.42, and is 0.10 to 0.40. The range is more preferable, and the range of 0.10 to 0.30 is further preferable.
  • T represents a distance to a critical load in a scratch test under a constant load of 0.1 N in TD
  • M represents a scratch test under a constant load of 0.1 N in MD.
  • the values represented by the above formulas (1) and (2) are values indicating the anisotropy of the distance to the critical load in the scratch test, and the closer the value is to zero, the distance to the critical load. Indicates that is isotropic.
  • the “scratch test” in one embodiment of the present invention is, as shown in FIG. 2, applying a constant load to the indenter and moving the laminate horizontally while the laminate is compressed and deformed in the thickness direction. This is a test for measuring the stress generated at a certain indenter movement distance when the pressure is applied.
  • the laminate is a laminated porous film obtained by laminating a porous layer to be measured on a polyolefin porous film.
  • the state in which the laminated body is compressed and deformed in the thickness direction is a state in which the indenter is pressed into the porous layer.
  • the test is specifically carried out by the following method: (1) A laminate obtained by laminating a porous layer to be measured on a polyolefin porous film is cut into 20 mm ⁇ 60 mm. Then, the cut laminated body 3 is pasted on a 30 mm ⁇ 70 mm glass preparation, which is the substrate 2, with an aqueous paste, and dried at 25 ° C. for 24 hours to prepare a test sample. .. At the time of the above-mentioned bonding, be careful not to let air bubbles enter between the laminate and the glass slide. (2) The test sample prepared in the step (1) is installed in a micro scratch test device.
  • a table of the test apparatus was moved toward the TD of the laminated body at 5 mm / min while the vertical load of 0.1 N was applied on the test sample. At a speed of 10 mm. During that time, a frictional force, which is a stress generated between the diamond indenter and the test sample, is measured. (3) A curve graph showing the relationship between the displacement of the stress measured in the step (2) and the moving distance of the table is created. From the curve graph, as shown in FIG. 3, the critical load value and the distance to reach the critical load in TD are calculated. (4) The moving direction of the table is changed to MD, and the above steps (1) to (3) are repeated to calculate the critical load value and the distance to reach the critical load in MD.
  • the distance to the critical load value calculated by the scratch test is (a) an index of plastic deformation easiness of the surface of the laminated porous film, (b) an index of transmissibility of shear stress to the surface opposite to the measurement surface. Becomes The long distance to the critical load value means that in the laminated porous film to be measured, (a ') the surface layer portion is less likely to be plastically deformed, and (b') the transmission of shear stress to the surface opposite to the measurement surface. Is low, that is, it is difficult to transmit stress.
  • the ion permeation resistance of the porous layer increases, and the resistance of the separator in the non-aqueous electrolyte secondary battery increases.
  • the above formulas (1) and (2) are less than 0. 10
  • it is considered that the structure of the porous layer has an extremely high isotropic structure.
  • the structure of the porous layer has an excessively high isotropic property, in a non-aqueous electrolyte secondary battery incorporating the porous layer, the electrolyte receiving ability of the porous layer during battery operation tends to be excessively high. There is.
  • the electrolyte solution supply capacity of the polyolefin porous film and the electrode that is the separator base material that supplies the electrolyte solution to the porous layer has a flow of the electrolyte solution of the entire non-aqueous electrolyte secondary battery. It will be rate limiting. As a result, the resistance of the separator in the non-aqueous electrolyte secondary battery increases.
  • the median particle diameter of the inorganic filler is preferably in the range of 0.1 ⁇ m to 11 ⁇ m, more preferably in the range of 0.1 ⁇ m to 10 ⁇ m, and 0.1 ⁇ m to The range is more preferably 5 ⁇ m, and particularly preferably 0.5 ⁇ m.
  • the method for measuring the median particle diameter of the inorganic filler is not particularly limited, but for example, it is measured by the method described in the examples.
  • the center particle size of the inorganic filler is larger than 11 ⁇ m, the film thickness of the heat-resistant layer increases and unevenness occurs, resulting in unevenness in ion permeation of the porous layer. As a result, the resistance of the separator in the non-aqueous electrolyte secondary battery incorporating the porous layer tends to increase.
  • the median particle diameter of the inorganic filler is less than 0.1 ⁇ m, the viscosity of the coating liquid containing the inorganic filler becomes high, which may cause dilatancy. As a result, the coating liquid has poor coating performance, which may cause uneven coating on the porous layer.
  • the central particle diameter of the inorganic filler is small, the amount of binder required to bind the inorganic filler increases.
  • the ion permeation resistance of the porous layer increases, and the resistance of the separator in the non-aqueous electrolyte secondary battery increases.
  • the BET specific surface area per unit area of the inorganic filler is preferably 100 m 2 / g or less, more preferably 50 m 2 / g or less, and 10 m 2 / g. It may be the following.
  • the method for measuring the BET specific surface area per unit area of the inorganic filler is not particularly limited, and examples thereof include a method including the steps (1) to (3) below.
  • the pretreatment device and the measurement device are not particularly limited.
  • BELPREP-vacII manufactured by Microtrac Bell Co., Ltd.
  • BELSORP-mini manufactured by Microtrac Bell Co., Ltd.
  • the measurement conditions for measuring the specific surface area of the filler are not particularly limited and can be appropriately set by those skilled in the art.
  • the BET specific surface area per unit area of the inorganic filler is larger than 100 m 2 / g, the filler oiling property is increased due to the increase in the BET specific surface area, and accordingly, the properties of the porous layer as a coating liquid are decreased, There is a risk of poor coatability. As a result, the resistance of the separator in the non-aqueous electrolyte secondary battery incorporating the porous layer tends to increase.
  • the method for producing the porous layer according to the embodiment of the present invention is not particularly limited, but for example, one of the following steps (1) to (3) may be used on the substrate, A method of forming a porous layer containing the inorganic filler and the resin can be mentioned.
  • the porous layer can be produced by depositing the resin and then drying it to remove the solvent.
  • the coating liquid in steps (1) to (3) may be in a state in which the inorganic filler is dispersed and the resin is dissolved.
  • the solvent can be said to be a solvent for dissolving the resin and a dispersion medium for dispersing the resin or the inorganic filler.
  • a step of forming a porous layer by applying a coating liquid containing the inorganic filler and fine particles of the resin on a base material and drying and removing the solvent in the coating liquid.
  • the liquid property of the coating liquid is made acidic by using a low-boiling organic acid, A step of depositing a resin to form a porous layer.
  • the solvent does not adversely affect the base material, dissolves the resin uniformly and stably, and disperses the inorganic filler uniformly and stably.
  • the solvent include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, acetone and water.
  • the deposition solvent for example, isopropyl alcohol or t-butyl alcohol is preferably used.
  • the low boiling point organic acid for example, paratoluenesulfonic acid, acetic acid, etc. can be used.
  • the orientation of the porous layer according to the embodiment of the present invention, that is, the above formulas (1) and (2), it is used for producing the porous layer, as shown below.
  • the solid content concentration of the coating liquid containing the inorganic filler and the resin, and the coating shear rate when the coating liquid is coated on the substrate can be adjusted.
  • a suitable solid content concentration of the coating liquid may vary depending on the type of filler, etc., but generally it is preferably more than 20% by weight and 40% by weight or less. Since the solid content concentration is within the above range, the viscosity of the coating liquid can be appropriately maintained, and as a result, the above formulas (1) and (2) can be controlled within the above suitable range. preferable.
  • the coating shear rate at the time of applying the coating liquid on the substrate may vary depending on the type of filler, etc., but generally it is preferably 2 (1 / s) or more and 4 (1 / s). More preferably, it is from s) to 50 (1 / s).
  • the coating shear rate when a plate-shaped metal oxide such as hexagonal plate-shaped zinc oxide is used as the inorganic filler, when the coating shear rate is increased, a high shearing force is applied to the metal oxide, so that it is anisotropic.
  • the above formulas (1) and (2) have values within the specified range.
  • the coating shear rate is reduced, the shearing force is not applied to the metal oxide, so that the metal oxide is oriented isotropically, and the above formulas (1) and (2) become smaller than the specified range.
  • the inorganic filler is a long fiber diameter metal oxide such as wollastonite having a long fiber diameter
  • the coating shear rate is increased, long fibers are entangled with each other, or the length of the doctor blade is long. Since the fibers are caught by the fibers, the orientations are different, and the orientations are anisotropic, and the above-described formulas (1) and (2) are within the specified range.
  • the coating shear rate is reduced, the long fibers do not become entangled with each other and do not get caught by the blade of the doctor blade, so that the orientation becomes easy and the orientation becomes isotropic, and the above formulas (1) and ( 2) becomes larger than the specified range.
  • the non-aqueous electrolyte in one embodiment of the present invention contains an additive having an ionic conductivity decrease rate L represented by the following formula (A) of 1.0% or more and 6.0% or less, 0.5 ppm to 300 ppm. contains.
  • L (LA-LB) / LA ...
  • LA is a reference in which LiPF 6 is dissolved in a mixed solvent containing ethylene carbonate, ethylmethyl carbonate and diethyl carbonate in a volume ratio of 3: 5: 2 so that the concentration becomes 1 mol / L.
  • the ionic conductivity (mS / cm) of the electrolyte for use is shown.
  • LB represents the ionic conductivity (mS / cm) of the electrolytic solution prepared by dissolving 1.0% by weight of the additive in the reference electrolytic solution.
  • the additive is not particularly limited as long as it is a compound that satisfies the ionic conductivity reduction rate L represented by the formula (A) of 1.0% or more and 6.0% or less.
  • examples of such a compound include pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], triethyl phosphate, vinylene carbonate, propane sultone, 2,6-dione.
  • the non-aqueous electrolytic solution contains an electrolyte and an organic solvent.
  • the electrolyte include an electrolyte containing lithium.
  • the electrolyte containing lithium for example, LiClO 4, LiPF 6, LiAsF 6, LiSbF 6, LiBF 4, LiCF 3 SO 3, LiN (CF 3 SO 2) 2, LiC (CF 3 SO 2) 3, Examples thereof include metal salts such as Li 2 B 10 Cl 10 , lithium salts of lower aliphatic carboxylic acids and lithium salts such as LiAlCl 4 .
  • the electrolyte may be used alone or in combination of two or more kinds.
  • organic solvent examples include carbonates, ethers, esters, nitriles, amides, carbamates and sulfur-containing compounds, and fluorine groups introduced into these organic solvents.
  • An aprotic polar solvent such as a fluorine-containing organic solvent may be used.
  • the organic solvent may be used alone or in combination of two or more.
  • the organic solvent is preferably a mixed solvent containing a cyclic compound such as ethylene carbonate and a chain compound such as ethylmethyl carbonate and diethyl carbonate.
  • the mixed solvent contains the cyclic compound and the chain compound preferably in a volume ratio of 2: 8 to 4: 6, more preferably in a volume ratio of 2: 8 to 3: 7, and particularly preferably. Is included in a volume ratio of 3: 7.
  • the mixed solvent in which the cyclic compound and the chain compound are mixed at a volume ratio of 3: 7 is an organic solvent that is generally used in the non-aqueous electrolyte solution of the non-aqueous electrolyte secondary battery.
  • the additive in one embodiment of the present invention reduces the ionic conductivity of the reference electrolyte solution.
  • the following reasons can be considered as reasons why the reduction of the charge capacity after high-rate discharge can be suppressed by adding the additive to the non-aqueous electrolyte solution.
  • the dissociation degree of ions in the non-aqueous electrolyte may be reduced. This can reduce the depletion of ions at the interface between the separator and the electrode during charge / discharge, particularly when the battery is operated at high speed. Therefore, it is considered that the reduction of the charge capacity after the high rate discharge can be suppressed.
  • the non-aqueous electrolyte solution contains the additive in an amount of 0.5 ppm or more, preferably 20 ppm or more, and more preferably 45 ppm or more.
  • the non-aqueous electrolyte contains the additive in an amount of 300 ppm or less, preferably 250 ppm or less, and 180 ppm or less. Is more preferable.
  • the degree of ion dissociation in the vicinity of the positive electrode during repeated charging and discharging, particularly when the battery is operated at a high speed It is strongly influenced by the amount of additives.
  • the nonaqueous electrolyte secondary battery according to the embodiment of the present invention can suitably reduce the degree of dissociation of ions near the positive electrode regardless of the type of the nonaqueous electrolyte. That is, regardless of the type and amount of the electrolyte contained in the non-aqueous electrolytic solution, and the type of the organic solvent contained, the addition of 0.5 ppm or more and 300 ppm or less of the additive causes dissociation of ions near the positive electrode.
  • the degree can be suitably reduced. As a result, it is possible to suppress a decrease in charge capacity after high rate discharge.
  • non-aqueous electrolytic Examples include a method of pre-dissolving the additive in the non-aqueous electrolyte solution to be injected into the container that will be the housing of the liquid secondary battery, so that the content of the additive is 0.5 ppm or more and 300 ppm or less. it can.
  • the positive electrode in one embodiment of the present invention is not particularly limited as long as it is generally used as the positive electrode of a non-aqueous electrolyte secondary battery.
  • a positive electrode sheet having a structure in which an active material layer containing a positive electrode active material and a binder is formed on a positive electrode current collector can be used as the positive electrode.
  • the active material layer may further contain a conductive agent.
  • the positive electrode active material includes, for example, a material capable of being doped / dedoped with metal ions such as lithium ions or sodium ions.
  • metal ions such as lithium ions or sodium ions.
  • Specific examples of the material include a lithium composite oxide containing at least one transition metal such as V, Mn, Fe, Co, and Ni.
  • Examples of the conductive agent include natural graphite, artificial graphite, cokes, carbon black, pyrolytic carbons, carbon fibers and carbonaceous materials such as organic polymer compound fired bodies.
  • the conductive agent may be used alone or in combination of two or more kinds.
  • binder examples include fluororesin such as polyvinylidene fluoride (PVDF), acrylic resin, and styrene-butadiene rubber.
  • PVDF polyvinylidene fluoride
  • acrylic resin acrylic resin
  • styrene-butadiene rubber examples include fluororesin such as polyvinylidene fluoride (PVDF), acrylic resin, and styrene-butadiene rubber.
  • the binder also has a function as a thickener.
  • Examples of the positive electrode current collector include conductors such as Al, Ni and stainless steel. Among them, Al is more preferable because it is easily processed into a thin film and is inexpensive.
  • the positive electrode sheet may be produced, for example, by pressure molding a positive electrode active material, a conductive agent and a binder on a positive electrode current collector; a positive electrode active material, a conductive agent and a binder using an appropriate organic solvent. Is applied to a positive electrode current collector, dried, and then pressed to fix it to the positive electrode current collector; and the like.
  • the negative electrode in one embodiment of the present invention is not particularly limited as long as it is generally used as a negative electrode of a non-aqueous electrolyte secondary battery.
  • a negative electrode sheet having a structure in which an active material layer containing a negative electrode active material and a binder is formed on a negative electrode current collector can be used as the negative electrode.
  • the active material layer may further contain a conductive agent.
  • the negative electrode active material for example, a material capable of doping / dedoping metal ions such as lithium ions or sodium ions can be mentioned.
  • the material include a carbonaceous material and the like.
  • the carbonaceous material include natural graphite, artificial graphite, cokes, carbon black and pyrolytic carbons.
  • Examples of the negative electrode current collector include Cu, Ni and stainless steel.
  • Cu is more preferable because it is difficult to form an alloy with lithium and is easily processed into a thin film.
  • Examples of the method for producing the negative electrode sheet include a method in which the negative electrode active material is pressure-molded on the negative electrode current collector; the negative electrode active material is made into a paste using an appropriate organic solvent, and then the paste is used as the negative electrode current collector. And the like, and then pressurizing and fixing to the negative electrode current collector; and the like.
  • the paste preferably contains the conductive agent and the binder.
  • the non-aqueous electrolyte secondary battery in one embodiment of the present invention may include a polyolefin porous film.
  • a polyolefin porous film may only be called a "porous film.”
  • the porous film contains a polyolefin-based resin as a main component and has a large number of pores connected to the inside thereof, so that a gas and a liquid can pass from one surface to the other surface.
  • the porous film alone can serve as a separator for a non-aqueous electrolyte secondary battery. It can also be a base material of the laminated separator for a non-aqueous electrolyte secondary battery in which the above-mentioned porous layer is laminated.
  • a laminate in which the porous layer is laminated in the present specification, also referred to as "non-aqueous electrolyte secondary battery laminated separator” or “laminated separator” .
  • the separator for a non-aqueous electrolyte secondary battery in one embodiment of the present invention may further include other layers such as an adhesive layer, a heat resistant layer, and a protective layer, in addition to the polyolefin porous film.
  • the proportion of polyolefin in the porous film is 50% by volume or more of the entire porous film, more preferably 90% by volume or more, and further preferably 95% by volume or more. Further, it is more preferable that the polyolefin contains a high molecular weight component having a weight average molecular weight of 5 ⁇ 10 5 to 15 ⁇ 10 6 . In particular, when the polyolefin contains a high molecular weight component having a weight average molecular weight of 1,000,000 or more, the strength of the separator for a non-aqueous electrolyte secondary battery is improved, which is more preferable.
  • the polyolefin which is a thermoplastic resin
  • a copolymer may be used.
  • the homopolymer include polyethylene, polypropylene and polybutene.
  • the copolymer include ethylene-propylene copolymer.
  • polyethylene is more preferable because it can block excessive current from flowing at lower temperatures. Note that blocking the flow of this excessive current is also referred to as shutdown.
  • the polyethylene include low density polyethylene, high density polyethylene, linear polyethylene (ethylene- ⁇ -olefin copolymer), and ultrahigh molecular weight polyethylene having a weight average molecular weight of 1,000,000 or more. Among these, ultrahigh molecular weight polyethylene having a weight average molecular weight of 1,000,000 or more is more preferable.
  • the thickness of the porous film is preferably 4 to 40 ⁇ m, more preferably 5 to 30 ⁇ m, and further preferably 6 to 15 ⁇ m.
  • the basis weight per unit area of the porous film can be appropriately determined in consideration of strength, film thickness, weight and handleability.
  • the basis weight is preferably 4 to 20 g / m 2 , and preferably 4 to 12 g / m 2 so that the weight energy density and the volume energy density of the non-aqueous electrolyte secondary battery can be increased. More preferably, it is more preferably 5 to 10 g / m 2 .
  • the air permeability of the porous film is preferably 30 to 500 sec / 100 mL in Gurley value, and more preferably 50 to 300 sec / 100 mL.
  • the air permeability of the laminated separator for a non-aqueous electrolyte secondary battery in which the above-mentioned porous layer is laminated on the porous film is preferably 30 to 1000 sec / 100 mL in terms of Gurley value, and is 50 to 800 sec / 100 mL. Is more preferable. Since the laminated separator for a non-aqueous electrolyte secondary battery has the above-mentioned air permeability, it is possible to obtain sufficient ion permeability in the non-aqueous electrolyte secondary battery.
  • the porosity of the porous film is preferably 20 to 80% by volume so as to increase the holding amount of the electrolytic solution and to surely prevent the flow of an excessive current at a lower temperature. It is more preferably 30 to 75% by volume.
  • the pore size of the pores of the porous film is 0.3 ⁇ m or less so that sufficient ion permeability can be obtained and particles can be prevented from entering the positive electrode and the negative electrode. Is preferable, and 0.14 ⁇ m or less is more preferable.
  • the method for producing the polyolefin porous film is not particularly limited.
  • a sheet-shaped polyolefin resin composition is prepared by kneading a polyolefin resin, a pore-forming agent such as an inorganic filler and a plasticizer, and optionally an antioxidant and the like and then extruding the kneaded product.
  • the polyolefin resin composition from which the pore-forming agent has been removed may be stretched to produce a polyolefin porous film. it can.
  • the above-mentioned inorganic filler is not particularly limited, and examples thereof include inorganic fillers, specifically calcium carbonate and the like.
  • the plasticizer is not particularly limited, and examples thereof include low molecular weight hydrocarbons such as liquid paraffin.
  • a method including the following steps can be mentioned.
  • A a step of kneading an ultrahigh molecular weight polyethylene, a low molecular weight polyethylene having a weight average molecular weight of 10,000 or less, a pore forming agent such as calcium carbonate or a plasticizer, and an antioxidant to obtain a polyolefin resin composition
  • B a step of rolling the obtained polyolefin resin composition with a pair of rolling rollers and gradually cooling it while pulling it with a take-up roller having a different speed ratio to form a sheet
  • C a step of removing the pore forming agent from the obtained sheet with a suitable solvent
  • D A step of stretching the sheet from which the pore forming agent has been removed at an appropriate stretching ratio.
  • Method for producing laminated separator for non-aqueous electrolyte secondary battery examples include, for example, in the above-mentioned “method for producing a porous layer”, as the base material to which the coating liquid is applied, The method of using a polyolefin porous film can be mentioned.
  • the porous layer is laminated on one side or both sides of the polyolefin porous film to obtain a non-aqueous electrolyte secondary battery laminated separator.
  • Non-aqueous electrolyte secondary battery As a method for manufacturing the non-aqueous electrolyte secondary battery according to the embodiment of the present invention, a conventionally known manufacturing method can be adopted. For example, by arranging the positive electrode, the polyolefin porous film, and the negative electrode in this order, a member for a non-aqueous electrolyte secondary battery is formed.
  • the porous layer may be present between the polyolefin porous film and at least one of the positive electrode and the negative electrode.
  • the member for a non-aqueous electrolyte secondary battery is put in a container which is a casing of the non-aqueous electrolyte secondary battery. After filling the inside of the container with the non-aqueous electrolyte, the container is sealed while reducing the pressure. Thereby, the non-aqueous electrolyte secondary battery according to the embodiment of the present invention can be manufactured.
  • Film thickness (unit: ⁇ m)
  • the thicknesses of the non-aqueous electrolyte secondary battery separator and the porous layer were measured using a high precision digital length measuring machine (VL-50) manufactured by Mitutoyo Corporation.
  • the film thickness of the porous layer was a value obtained by subtracting the film thickness of the part where the porous layer was not formed from the film thickness of the part where the porous layer was formed in each laminate.
  • an arabic Yamato aqueous liquid paste (manufactured by Yamato Co., Ltd.) diluted 5 times with water was applied to the entire surface of the cut laminate for the non-aqueous electrolyte secondary battery separator, that is, the base material side, to give a weight of 1.5 g. A small amount of about / m 2 was applied thinly. Then, the surface coated with the aqueous liquid paste was pasted on a glass slide having a size of 30 mm ⁇ 70 mm, and then dried at a temperature of 25 ° C. for 24 hours to prepare a test sample. At the time of the above-mentioned bonding, bubbles were prevented from entering between the laminate and the glass slide.
  • step (i) The test sample prepared in step (i) was placed in a micro scratch tester (manufactured by CSEM Instruments). In the test apparatus, a vertical load of 0.1 N was applied on the test sample by a conical diamond indenter having an apex angle of 120 ° and a tip radius of 0.2 mm. The table was moved toward the TD of the laminate at a speed of 5 mm / min and a distance of 10 mm. During that time, the stress generated between the diamond indenter and the test sample, that is, the frictional force was measured. (Iii) A curve graph showing the relationship between the displacement of the stress measured in the step (ii) and the moving distance of the table was created.
  • Reduction rate of ionic conductivity (%) LiPF 6 was dissolved in a mixed solvent prepared by mixing ethylene carbonate, ethylmethyl carbonate and diethyl carbonate in a volume ratio of 3: 5: 2 to a concentration of 1 mol / L to prepare a reference electrolyte solution. Obtained. Each additive was added to the reference electrolyte solution to be 1% and dissolved, and then the ionic conductivity (mS / cm) was measured. The ionic conductivity was measured using an electric conductivity meter (ES-71) manufactured by Horiba Ltd. The ionic conductivity decrease rate is represented by the following formula (A).
  • L (LA-LB) / LA ... (A) L: reduction rate of ionic conductivity (%), LA: ionic conductivity (mS / cm) before addition, LB: Ionic conductivity (mS / cm) after addition.
  • a non-aqueous electrolyte secondary battery assembled as described below was operated at 25 ° C. in a voltage range of 4.1 to 2.7 V and a charging current value of 0.2 C.
  • the CC-CV charging (final current condition 0.02C) and the CC discharging having a discharge current value of 0.2C were set as one cycle, and the initial charge / discharge for four cycles was performed at 25 ° C.
  • CC-CV charging is a charging method in which charging is performed with a set constant current, and after reaching a predetermined voltage, the current is reduced while maintaining the voltage.
  • CC discharge is a method of discharging to a predetermined voltage with a set constant current. The same applies to the following.
  • CC-CV charge with a charge current value of 1C (end current condition 0.02C), discharge current value of 0.2C, 1C, 5C, 10C in this order.
  • CC discharge was carried out.
  • Charging / discharging was performed for 3 cycles at 55 ° C. for each rate.
  • the voltage range was set to 2.7V to 4.2V.
  • the charge capacity at the time of 1C charge of the 3rd cycle at the time of 10C discharge rate characteristic measurement was measured, and it was set as the charge capacity after high rate discharge.
  • the designed capacity of the non-aqueous electrolyte secondary batteries manufactured in Examples and Comparative Examples was 20.5 mAh.
  • a separator for a non-aqueous electrolyte secondary battery was produced using polyethylene. Specifically, 70 parts by weight of ultra high molecular weight polyethylene powder (340M, manufactured by Mitsui Chemicals, Inc.) and 30 parts by weight of polyethylene wax having a weight average molecular weight of 1000 (FNP-0115, manufactured by Nippon Seiro Co., Ltd.) are mixed. To obtain mixed polyethylene.
  • ultra high molecular weight polyethylene powder (340M, manufactured by Mitsui Chemicals, Inc.)
  • FNP-0115 polyethylene wax having a weight average molecular weight of 1000
  • this polyethylene resin composition was rolled by a pair of rollers whose surface temperature was set to 150 ° C. to prepare a sheet.
  • This sheet was immersed in an aqueous hydrochloric acid solution prepared by mixing 0.5 mol% of a nonionic surfactant in 4 mol / L hydrochloric acid to dissolve and remove calcium carbonate.
  • seat was stretched 6 times at 105 degreeC, and the polyolefin porous film was produced.
  • the porosity of the polyolefin porous film was 53%, the basis weight was 7 g / m 2 , and the film thickness was 16 ⁇ m.
  • This polyolefin porous film was used as a separator 1 for a non-aqueous electrolyte secondary battery.
  • the volume-based particle size distribution of the inorganic filler was calculated by measuring the central particle size (D50) using a laser diffraction particle size distribution analyzer SALD2200 manufactured by Shimadzu Corporation.
  • the particle size at which the volume-based cumulative distribution is 50% is referred to as D50.
  • the median particle diameter of the inorganic filler made of a mixture of ⁇ -alumina and hexagonal plate-shaped zinc oxide was 0.8 ⁇ m.
  • the specific surface area of the filler was measured using BELSORP-mini (manufactured by Microtrac Bell Co., Ltd.).
  • the adsorption-desorption isotherm by nitrogen of the filler that had been vacuum dried at a pretreatment temperature of 80 ° C. for 8 hours was measured by the constant volume method, and calculated by the BET method.
  • the various conditions in the constant volume method are as follows: adsorption temperature; 77K, adsorbate; nitrogen, saturated vapor pressure; measured value, adsorbate cross section; 0.162 nm 2 , equilibrium waiting time; 500 sec.
  • the "equilibrium waiting time” means the waiting time after reaching the adsorption equilibrium state in which the pressure change during desorption becomes a predetermined value or less.
  • the pore volume was calculated by the MP method and the BJH method, and the pretreatment device used was BELPREP-vacII (manufactured by Microtrac Bell Co., Ltd.). As a result, the BET specific surface area of the filler was 4.5 m 2 / g.
  • a vinylidene fluoride-hexafluoropropylene copolymer (manufactured by Arkema Ltd .; trade name “KYNAR2801”) was used.
  • the inorganic filler, vinylidene fluoride-hexafluoropropylene copolymer and solvent were mixed in the following proportions. That is, after mixing 10 parts by weight of vinylidene fluoride-hexafluoropropylene copolymer with 90 parts by weight of inorganic filler, the solid content of the inorganic filler and vinylidene fluoride-hexafluoropropylene copolymer in the resulting mixed liquid.
  • the solvent was mixed so that the concentration of was 40% by weight.
  • the obtained mixed liquid was stirred and mixed with a thin film swivel type high speed mixer (Filmiku (registered trademark) manufactured by Primix Co., Ltd.) to obtain a uniform coating liquid.
  • the obtained coating liquid was applied to one side of the separator 1 for non-aqueous electrolyte secondary battery by a doctor blade method at a coating shear rate of 39.4 (1 / s), and the non-aqueous electrolysis was performed.
  • a coating film was formed on one surface of the liquid secondary battery separator 1.
  • the coating film was dried at 65 ° C. for 20 minutes to form the porous layer 1 on one surface of the separator 1 for non-aqueous electrolyte secondary battery.
  • a laminate 1 including the separator 1 for non-aqueous electrolyte secondary battery and the porous layer 1 was obtained.
  • the basis weight of the porous layer 1 was 7 g / m 2 and the thickness was 4 ⁇ m. Table 1 shows the measurement results of various physical properties of the inorganic filler and the laminate 1.
  • a commercially available positive electrode manufactured by applying LiNi 0.5 Mn 0.3 Co 0.2 O 2 / conductive agent / PVDF (weight ratio 92/5/3) to an aluminum foil was used.
  • An aluminum foil was applied to the commercially available positive electrode so that the size of the part where the positive electrode active material layer was formed was 40 mm ⁇ 35 mm, and the part where the width of 13 mm was not formed and the positive electrode active material layer was not formed remained on the outer periphery thereof. It was cut out to obtain a positive electrode.
  • the positive electrode active material layer had a thickness of 58 ⁇ m and a density of 2.50 g / cm 3 .
  • a commercially available negative electrode manufactured by applying graphite / styrene-1,3-butadiene copolymer / sodium carboxymethyl cellulose (weight ratio 98/1/1) to a copper foil was used.
  • a copper foil was applied to the commercially available negative electrode so that the size of the part where the negative electrode active material layer was formed was 50 mm ⁇ 40 mm, and the part where the width of 13 mm was not formed and the negative electrode active material layer was not formed remained on the outer periphery thereof. It was cut out to obtain a negative electrode.
  • the negative electrode active material layer had a thickness of 49 ⁇ m and a density of 1.40 g / cm 3 .
  • LiPF 6 was dissolved in a mixed solvent in which ethylene carbonate, ethylmethyl carbonate, and diethyl carbonate were mixed at a volume ratio of 3: 5: 2 so that the concentration thereof was 1 mol / L, to prepare an electrolytic solution stock solution 1.
  • This electrolytic solution stock solution 1 is an aprotic polar solvent electrolytic solution containing Li + ions.
  • Addition liquid 1 was prepared by adding diethyl carbonate to 10.3 mg of dibutylhydroxytoluene (BHT, ionic conductivity reduction rate: 5.3%) to make a volume of 5 mL.
  • a non-aqueous electrolyte solution 1 was prepared by mixing 300 ⁇ L of the additive solution 1 and 1700 ⁇ L of the electrolyte solution stock solution 1.
  • Table 2 shows the content of the additive in the non-aqueous electrolyte solution 1.
  • a non-aqueous electrolyte secondary battery was manufactured by the following method using the positive electrode, the negative electrode, the laminate 1, and the non-aqueous electrolyte solution 1.
  • the produced non-aqueous electrolyte secondary battery was designated as non-aqueous electrolyte secondary battery 1.
  • a non-aqueous electrolyte secondary battery member 1 was obtained by stacking the positive electrode, the laminate 1 with the porous layer facing the positive electrode side, and the negative electrode in this order in a laminate pouch.
  • the positive electrode and the negative electrode were arranged such that the entire main surface of the positive electrode active material layer of the positive electrode was included in the range of the main surface of the negative electrode active material layer of the negative electrode. That is, the positive electrode and the negative electrode were arranged such that the entire main surface of the positive electrode active material layer of the positive electrode overlaps the main surface of the negative electrode active material layer of the negative electrode.
  • the non-aqueous electrolyte secondary battery member 1 was placed in a previously prepared bag in which an aluminum layer and a heat seal layer were laminated, and 0.23 mL of the non-aqueous electrolyte solution 1 was further placed in this bag. I put it in. Then, the inside of the bag was depressurized and the bag was heat-sealed to manufacture the non-aqueous electrolyte secondary battery 1.
  • Example 2 [Preparation of non-aqueous electrolyte secondary battery] (Preparation of non-aqueous electrolyte) LiPF 6 was dissolved in a mixed solvent in which ethylene carbonate and diethyl carbonate were mixed at a volume ratio of 3: 7 so that the concentration thereof was 1 mol / L, to prepare an electrolyte solution stock solution 2.
  • Addition liquid 2 was prepared by adding diethyl carbonate to 10.0 mg of vinylene carbonate (VC, reduction rate of ionic conductivity: 1.3%) to make a volume of 5 mL. 200 ⁇ L of the additive solution 2 and 1800 ⁇ L of the electrolytic solution stock solution 2 were mixed, and 900 ⁇ L of the electrolytic solution stock solution 2 was added to 100 ⁇ L of the mixed solution of the additive solution 2 and the electrolytic solution stock solution 2 to give an additive solution 3.
  • a non-aqueous electrolyte solution 2 was prepared by mixing 50 ⁇ L of the additive solution 3 and 1950 ⁇ L of the electrolyte solution stock solution 2. Table 2 shows the content of the additive in the non-aqueous electrolyte solution 2.
  • a non-aqueous electrolyte secondary battery was produced in the same manner as in Example 1 except that the non-aqueous electrolyte solution 2 was used instead of the non-aqueous electrolyte solution 1.
  • the produced non-aqueous electrolyte secondary battery was used as a non-aqueous electrolyte secondary battery 2.
  • Example 3 [Production of Laminated Body Comprising Nonaqueous Electrolyte Secondary Battery Separator and Porous Layer]
  • As the inorganic filler hexagonal plate-shaped zinc oxide having a mass percentage of oxygen atoms of 20% (manufactured by Sakai Chemical Industry Co., Ltd., trade name: XZ-100F) was used.
  • a solid comprising the inorganic filler and the vinylidene fluoride-hexafluoropropylene copolymer in the resulting mixed liquid after mixing 10 parts by weight of the vinylidene fluoride-hexafluoropropylene copolymer with 90 parts by weight of the inorganic filler.
  • the mixture was prepared by mixing the solvents so that the concentration of the components was 37% by weight.
  • the porous layer 2 was formed instead of the porous layer 1 by applying the coating liquid at a coating shear rate of 3.9 (1 / s).
  • the central particle diameter of the inorganic filler made of hexagonal plate-shaped zinc oxide was 0.4 ⁇ m, and the BET specific surface area was 7.3 m 2 / g.
  • Table 1 shows the measurement results of various physical properties of the inorganic filler and the laminate 2.
  • Non-aqueous electrolyte secondary battery in the same manner as in Example 1 except that the laminate 2 was used instead of the laminate 1 and the non-aqueous electrolyte 3 was used instead of the non-aqueous electrolyte 1.
  • the produced non-aqueous electrolyte secondary battery was used as a non-aqueous electrolyte secondary battery 3.
  • Example 4 [Production of Laminated Body Comprising Nonaqueous Electrolyte Secondary Battery Separator and Porous Layer]
  • As the inorganic filler Wollastonite (Hayashi Kasei Co., Ltd., trade name: Wollastonite VM-8N) having an oxygen atomic mass percentage of 41% was used.
  • the -A solid comprising the inorganic filler and the vinylidene fluoride-hexafluoropropylene copolymer in the resulting mixed liquid after mixing 10 parts by weight of the vinylidene fluoride-hexafluoropropylene copolymer with 90 parts by weight of the inorganic filler.
  • the mixture was prepared by mixing the solvents so that the concentration of the components was 40% by weight.
  • the porous layer 3 was formed instead of the porous layer 1 by applying the coating liquid at a coating shear rate of 7.9 (1 / s).
  • the central particle diameter of the inorganic filler made of wollastonite was 10.6 ⁇ m, and the BET specific surface area was 1.3 m 2 / g.
  • Table 1 shows the measurement results of various physical properties of the inorganic filler and the laminate 3.
  • a non-aqueous electrolyte secondary battery was obtained in the same manner as in Example 1 except that the laminate 3 was used instead of the laminate 1 and the non-aqueous electrolyte 4 was used instead of the non-aqueous electrolyte 1.
  • the produced non-aqueous electrolyte secondary battery was used as a non-aqueous electrolyte secondary battery 4.
  • a non-aqueous electrolyte secondary battery was produced in the same manner as in Example 1 except that the non-aqueous electrolyte solution 5 was used instead of the non-aqueous electrolyte solution 1.
  • the produced non-aqueous electrolyte secondary battery was used as a non-aqueous electrolyte secondary battery 5.
  • Example 2 [Production of Laminated Body Comprising Nonaqueous Electrolyte Secondary Battery Separator and Porous Layer]
  • a laminate 4 including the separator 1 for non-aqueous electrolyte secondary battery and the porous layer 4 was obtained in the same manner as in Example 1 except for the following.
  • a solid comprising the inorganic filler and the vinylidene fluoride-hexafluoropropylene copolymer in the resulting mixed liquid after mixing 10 parts by weight of the vinylidene fluoride-hexafluoropropylene copolymer with 90 parts by weight of the inorganic filler.
  • the mixture was prepared by mixing the solvents so that the concentration of the components was 40% by weight.
  • the porous layer 4 was formed instead of the porous layer 1 by applying the coating liquid at a coating shear rate of 7.9 (1 / s).
  • the central particle diameter of the inorganic filler made of borax was 27 ⁇ m, and the BET specific surface area was 2.5 m 2 / g.
  • Table 1 shows the measurement results of various physical properties of the inorganic filler and the laminate 4.
  • Nonaqueous electrolyte secondary battery in the same manner as in Example 1 except that the laminate 4 was used instead of the laminate 1 and the nonaqueous electrolyte solution 6 was used instead of the nonaqueous electrolyte solution 1.
  • the produced non-aqueous electrolyte secondary battery was used as a non-aqueous electrolyte secondary battery 6.
  • Example 3 [Preparation of non-aqueous electrolyte secondary battery] (Assembly of non-aqueous electrolyte secondary battery) A non-aqueous electrolyte secondary battery was produced in the same manner as in Example 1 except that the electrolyte solution 1 was used instead of the non-aqueous electrolyte 1. The produced non-aqueous electrolyte secondary battery was used as a non-aqueous electrolyte secondary battery 7.
  • Example 4 [Production of Laminated Body Comprising Nonaqueous Electrolyte Secondary Battery Separator and Porous Layer]
  • a laminate 5 including the separator 1 for non-aqueous electrolyte secondary battery and the porous layer 5 was obtained in the same manner as in Example 1 except for the following.
  • As the inorganic filler spherical alumina having a mass percentage of oxygen atoms of 47% (Sumitomo Chemical Co., Ltd., trade name: AA03) was used.
  • a solid comprising the inorganic filler and the vinylidene fluoride-hexafluoropropylene copolymer in the resulting mixed liquid after mixing 10 parts by weight of the vinylidene fluoride-hexafluoropropylene copolymer with 90 parts by weight of the inorganic filler.
  • the mixture was prepared by mixing the solvents so that the concentration of the components was 40% by weight.
  • the porous layer 5 was formed instead of the porous layer 1 by applying the coating liquid at a coating shear rate of 7.9 (1 / s).
  • the central particle diameter of the inorganic filler made of spherical alumina was 0.6 ⁇ m, and the BET specific surface area was 5.7 m 2 / g.
  • Table 1 shows the measurement results of various physical properties of the inorganic filler and the laminate 5.
  • Non-aqueous electrolyte secondary battery (Assembly of non-aqueous electrolyte secondary battery)
  • the non-aqueous electrolyte secondary battery according to an embodiment of the present invention is excellent in charge capacity after high-rate discharge, and thus is suitably used as a battery used in personal computers, mobile phones, personal digital assistants, and the like, and as a vehicle battery. can do.

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  • Cell Separators (AREA)

Abstract

Le but de la présente invention est de fournir une batterie secondaire à électrolyte non aqueux qui présente une excellente capacité de charge après une décharge à grande vitesse. Cette batterie secondaire à électrolyte non aqueux comprend : une couche poreuse pour laquelle, lorsque la couche poreuse est soumise à un test de rayure sous une charge constante de 0,1 N, l'anisotropie entre la distance par rapport à la charge critique dans la TD et la distance à la charge critique dans le MD se situe dans une plage spécifique ; une électrode positive ; une électrode négative ; et un électrolyte non aqueux qui contient 0,5 à 300 ppm d'un additif prescrit.
PCT/JP2019/042959 2018-11-01 2019-11-01 Batterie secondaire à électrolyte non aqueux WO2020091025A1 (fr)

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JP2001338684A (ja) * 2000-05-26 2001-12-07 Sony Corp 非水電解質電池
JP2011154987A (ja) * 2009-12-29 2011-08-11 Sony Corp 非水電解質および非水電解質電池
JP2017107848A (ja) * 2015-11-30 2017-06-15 住友化学株式会社 非水電解液二次電池用セパレータ
JP2017226122A (ja) * 2016-06-21 2017-12-28 住友化学株式会社 積層体
JP2018190710A (ja) * 2017-04-28 2018-11-29 住友化学株式会社 非水電解液二次電池用絶縁性多孔質層
JP2018200875A (ja) * 2017-05-29 2018-12-20 住友化学株式会社 非水電解液二次電池
JP2019029336A (ja) * 2017-07-31 2019-02-21 住友化学株式会社 非水電解液二次電池
JP2019139972A (ja) * 2018-02-09 2019-08-22 住友化学株式会社 非水電解液二次電池
JP2019139973A (ja) * 2018-02-09 2019-08-22 住友化学株式会社 非水電解液二次電池

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001338684A (ja) * 2000-05-26 2001-12-07 Sony Corp 非水電解質電池
JP2011154987A (ja) * 2009-12-29 2011-08-11 Sony Corp 非水電解質および非水電解質電池
JP2017107848A (ja) * 2015-11-30 2017-06-15 住友化学株式会社 非水電解液二次電池用セパレータ
JP2017226122A (ja) * 2016-06-21 2017-12-28 住友化学株式会社 積層体
JP2018190710A (ja) * 2017-04-28 2018-11-29 住友化学株式会社 非水電解液二次電池用絶縁性多孔質層
JP2018200875A (ja) * 2017-05-29 2018-12-20 住友化学株式会社 非水電解液二次電池
JP2019029336A (ja) * 2017-07-31 2019-02-21 住友化学株式会社 非水電解液二次電池
JP2019139972A (ja) * 2018-02-09 2019-08-22 住友化学株式会社 非水電解液二次電池
JP2019139973A (ja) * 2018-02-09 2019-08-22 住友化学株式会社 非水電解液二次電池

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