WO2014021290A1 - 非水電解質電池用セパレータ及び非水電解質電池 - Google Patents
非水電解質電池用セパレータ及び非水電解質電池 Download PDFInfo
- Publication number
- WO2014021290A1 WO2014021290A1 PCT/JP2013/070538 JP2013070538W WO2014021290A1 WO 2014021290 A1 WO2014021290 A1 WO 2014021290A1 JP 2013070538 W JP2013070538 W JP 2013070538W WO 2014021290 A1 WO2014021290 A1 WO 2014021290A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- separator
- adhesive
- porous layer
- electrolyte battery
- resin
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/46—Separators, membranes or diaphragms characterised by their combination with electrodes
- H01M50/461—Separators, membranes or diaphragms characterised by their combination with electrodes with adhesive layers between electrodes and separators
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
- B32B27/20—Layered products comprising a layer of synthetic resin characterised by the use of special additives using fillers, pigments, thixotroping agents
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
- B32B27/304—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising vinyl halide (co)polymers, e.g. PVC, PVDC, PVF, PVDF
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
- B32B7/04—Interconnection of layers
- B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/411—Organic material
- H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/411—Organic material
- H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
- H01M50/417—Polyolefins
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/411—Organic material
- H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
- H01M50/426—Fluorocarbon polymers
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/463—Separators, membranes or diaphragms characterised by their shape
-
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2255/00—Coating on the layer surface
- B32B2255/26—Polymeric coating
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2307/00—Properties of the layers or laminate
- B32B2307/30—Properties of the layers or laminate having particular thermal properties
- B32B2307/306—Resistant to heat
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2307/00—Properties of the layers or laminate
- B32B2307/50—Properties of the layers or laminate having particular mechanical properties
- B32B2307/54—Yield strength; Tensile strength
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2307/00—Properties of the layers or laminate
- B32B2307/70—Other properties
- B32B2307/718—Weight, e.g. weight per square meter
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2457/00—Electrical equipment
- B32B2457/10—Batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2220/00—Batteries for particular applications
- H01M2220/20—Batteries in motive systems, e.g. vehicle, ship, plane
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2220/00—Batteries for particular applications
- H01M2220/30—Batteries in portable systems, e.g. mobile phone, laptop
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/403—Manufacturing processes of separators, membranes or diaphragms
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
- H01M50/491—Porosity
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
- H01M50/494—Tensile strength
-
- 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 separator for a nonaqueous electrolyte battery and a nonaqueous electrolyte battery.
- Non-aqueous secondary batteries represented by lithium ion secondary batteries are widely used as power sources for portable electronic devices such as notebook computers, mobile phones, digital cameras, and camcorders. Furthermore, in recent years, these batteries have been studied for application to automobiles and the like because of their high energy density.
- the exterior of non-aqueous secondary batteries has been simplified.
- a battery can made of an aluminum can has been developed in place of the initially used stainless steel battery can, and a soft pack exterior made of an aluminum laminate pack is currently being developed.
- a porous layer made of a polyvinylidene fluoride resin (hereinafter, also referred to as “adhesive porous layer”) is formed on a polyolefin microporous film which is a conventional separator. It has been proposed (see, for example, Patent Document 1).
- the adhesive porous layer has a function as an adhesive that satisfactorily bonds the electrode and the separator when the electrode is hot-pressed on the electrode. Therefore, the adhesive porous layer contributes to the improvement of the cycle life of the soft pack battery.
- an adhesive porous layer is formed on a porous substrate such as a polyolefin microporous membrane (hereinafter also simply referred to as a substrate) by coating
- unevenness associated with coating in other words, coating
- the substrate usually has variations in thickness.
- the adhesiveness with the electrode also tends to vary.
- Such adhesive variation is directly related to the non-uniformity of ion permeability in the battery. Therefore, it is easy for ions to permeate between the part having the desired adhesion and the part having reduced adhesion in the separator. Is different.
- film deterioration tends to proceed at a portion where ion permeation is likely to occur, which causes a significant decrease in long-term cycle characteristics of the battery as a whole.
- the present invention has been made in view of the above, and is excellent in adhesiveness with an electrode, improves the cycle characteristics of the battery, and improves the cycle characteristics of the battery, and non-aqueous stably expresses the excellent cycle characteristics. It aims at providing an electrolyte battery, and makes it a subject to achieve this objective.
- ⁇ 3> The non-aqueous electrolyte battery separator according to ⁇ 1> or ⁇ 2>, wherein the adhesive resin is a polyvinylidene fluoride resin.
- the polyvinylidene fluoride-based resin has a weight average molecular weight of 600,000 to 3,000,000.
- ⁇ 5> The separator for a nonaqueous electrolyte battery according to any one of ⁇ 1> to ⁇ 4>, wherein an elongation in the MD direction or TD direction of the porous substrate is 50% or more and 200% or less.
- ⁇ 6> The separator for a nonaqueous electrolyte battery according to any one of ⁇ 1> to ⁇ 5>, wherein the puncture strength of the porous substrate is 200 g or more and 800 g or less.
- the adhesive porous layer contains a filler, and a mass ratio of the filler to the adhesive resin (mass of filler / mass of adhesive resin) is 0.01 or more and 0.05 or less.
- ⁇ 1>- ⁇ 6> The separator for a nonaqueous electrolyte battery according to any one of ⁇ 1> to ⁇ 6>.
- a separator for a non-aqueous electrolyte battery that is excellent in adhesiveness with an electrode and improves the cycle characteristics of the battery. Moreover, according to this invention, the nonaqueous electrolyte battery which expresses the outstanding cycling characteristics stably is provided.
- the nonaqueous electrolyte battery separator of the present invention and the nonaqueous electrolyte battery using the same will be described in detail.
- the numerical value range indicated by “ ⁇ ” means a numerical range including an upper limit value and a lower limit value.
- the “MD direction” is a so-called “machine direction” and means the long direction of the separator manufactured in a long shape.
- the “TD direction” is a so-called “width direction” and means a direction orthogonal to the long direction of the separator manufactured in a long shape.
- the separator for a non-aqueous electrolyte battery of the present invention is provided with a porous substrate and an adhesive porous layer provided on one or both sides of the porous substrate and containing an adhesive resin.
- the ratio of the standard deviation of the basis weight of the adhesive porous layer to the average value [g / m 2 ] (standard deviation / average value) is 0.3 or less.
- the basis weight of the adhesive porous layer can be regarded as the basis weight of the adhesive resin in the adhesive porous layer when the adhesive porous layer is composed only of the adhesive resin.
- the adhesive porous layer can be regarded as a mass of a solid content constituting the adhesive porous layer.
- the basis weight (g / m 2 ) of the adhesive porous layer or adhesive resin is the coating amount (g / m 2 ) after drying when the adhesive porous layer is provided by coating.
- ions are conducted mainly through the pores in the separator. Therefore, if there is variation in the thickness of the adhesive porous layer, the path length of each hole through which ions pass.
- the (distance) is long and short, and the ion permeability throughout the separator cannot be kept uniform.
- film deterioration easily proceeds in regions that easily transmit ions, and as a result, the cycle characteristics of the entire battery may be adversely affected. is there.
- One cause of the quality of ion permeability is variation in the basis weight of the adhesive porous layer.
- the adhesiveness of the adhesive porous layer in particular, when the adhesiveness with the electrode is improved and a battery is constructed, the cycle characteristics over a long period of time are dramatically improved. Further, by adjusting the variation in the basis weight of the adhesive porous layer within the range of the present invention, it is possible to reduce defects due to the slit when slitting the separator to a desired size, and to improve the manufacturing yield.
- the ratio represented by “(standard deviation of basis weight) / (average value of basis weight)” of the adhesive resin layer is more preferably 0.2 or less, further preferably 0.1 or less, and zero ( Ideally, there should be no variation.
- the ratio of the adhesive porous layer represented by “(standard deviation of basis weight) / (average value of basis weight)” was determined by obtaining the basis weight of the adhesive porous layer as follows. It is calculated using the average value and standard deviation obtained from (g / m 2 ).
- the basis weight of the adhesive porous layer is measured as follows. That is, first, 10 sample pieces obtained by cutting the separator into a size of 10 cm ⁇ 10 cm are prepared, and the basis weight of each sample piece is measured. Subsequently, the adhesive porous layer (coating layer) provided in each sample piece is dissolved and removed with a solvent, and the basis weight of each porous substrate is measured. Then, the basis weight of the adhesive porous layer of each sample piece is required by subtracting the basis weight of the porous substrate from the basis weight of the separator.
- standard deviation and average value mean general standard deviation and average value, and are defined as follows. That is, when there is a population composed of N pieces of data x 1 , x 2 ,..., X N , the “average value” is an arithmetic average (population average) of the population as shown in the following formula: m). That is, in the present invention, the average value of the basis weight of the adhesive porous layer can be obtained by summing the 10 basis weight values measured for a certain separator and dividing the result by 10.
- the unbiased variance ⁇ 2 is defined as follows:
- the positive square root ⁇ of this unbiased variance ⁇ 2 is defined as “standard deviation”. That is, in the present invention, the standard deviation of the basis weight of the adhesive porous layer is obtained by calculating the square root by obtaining the unbiased variance ⁇ 2 by applying the basis weight and average value of 10 points measured for a certain separator to the above formula. can get.
- the physical properties of the porous substrate for example, the variation in the thickness of the porous substrate.
- a method of selecting appropriate physical properties such as elongation, puncture strength, tensile strength, and Young's modulus of the porous substrate, or when the filler is included in the adhesive porous layer, The method of adjusting etc. are mentioned.
- the ratio (thickness variation) of the standard deviation of the thickness of the porous substrate to the average value of the thickness of the porous substrate is obtained from the obtained thickness ( ⁇ m) as follows. Calculated using the average value and standard deviation.
- the thickness of the porous substrate is measured as follows. That is, the porous substrate was cut into a size of 10 cm ⁇ 10 cm, and 10 sample pieces were prepared. For each sample piece, the thickness of the central part in the width direction (TD) is measured at 10 points at intervals of 1 cm in the length direction (MD) to obtain a total thickness of 100 points. Based on the thickness data of 100 points, the average value and the standard deviation are calculated in the same manner as in the case of the basis weight.
- a contact-type thickness meter for example, LITEMASIC manufactured by Mitutoyo Corporation
- a cylindrical terminal having a diameter of 5 mm is used for the measurement terminal, and the load is adjusted so that a load of 7 g is applied during the measurement.
- the porous substrate when the value represented by “(standard deviation of thickness) / (average value of thickness)” is 0.02 or less, there is a thickness variation in the surface direction of the layer provided on the substrate. Since it is kept small, the path length (distance) of the hole through which ions pass becomes more uniform. Thereby, the in-plane ion permeability can be made uniform, and the cycle characteristics when the battery is constructed can be stably maintained over a long period of time.
- the ratio represented by “(thickness standard deviation) / (average thickness)” is more preferably 0.01 or less, further preferably 0.005 or less, and ideally zero (no variation). .
- the method for controlling the variation in the thickness of the porous substrate is not particularly limited. For example, a commercially available porous substrate that satisfies the above-described thickness condition may be selected.
- the porous substrate in the present invention means a substrate having pores or voids therein.
- a substrate include a microporous film, a porous sheet made of a fibrous material such as a nonwoven fabric and a paper sheet, or one or more other porous layers laminated on the microporous film or the porous sheet.
- Composite porous sheet and the like are examples of such a substrate.
- a microporous membrane means a membrane that has a large number of micropores inside and has a structure in which these micropores are connected, allowing gas or liquid to pass from one surface to the other. To do.
- the material constituting the porous substrate may be either an organic material or an inorganic material as long as it is an electrically insulating material.
- the material constituting the porous substrate is preferably a thermoplastic resin from the viewpoint of imparting a shutdown function to the porous substrate.
- the shutdown function refers to a function of preventing the thermal runaway of the battery by blocking the movement of ions by dissolving the constituent materials and closing the pores of the porous base material when the battery temperature increases.
- the thermoplastic resin a thermoplastic resin having a melting point of less than 200 ° C. is suitable, and polyolefin is particularly preferable.
- a polyolefin microporous membrane As the porous substrate using polyolefin, a polyolefin microporous membrane is suitable.
- the polyolefin microporous membrane those having sufficient mechanical properties and ion permeability can be suitably used from among polyolefin microporous membranes applied to conventional separators for nonaqueous electrolyte batteries.
- the polyolefin microporous membrane preferably contains polyethylene from the viewpoint of exhibiting a shutdown function, and the polyethylene content is preferably 95% by mass or more.
- a polyolefin microporous film containing polyethylene and polypropylene is suitable from the viewpoint of imparting heat resistance that does not easily break when exposed to high temperatures.
- a polyolefin microporous membrane include a microporous membrane in which polyethylene and polypropylene are mixed in one layer.
- Such a microporous membrane preferably contains 95% by mass or more of polyethylene and 5% by mass or less of polypropylene from the viewpoint of achieving both a shutdown function and heat resistance.
- the polyolefin microporous membrane has a laminated structure of two or more layers, and at least one layer contains polyethylene and at least one layer contains a polyolefin microporous membrane having a structure containing polypropylene. .
- the polyolefin contained in the polyolefin microporous membrane preferably has a weight average molecular weight of 100,000 to 5,000,000. When the weight average molecular weight is 100,000 or more, sufficient mechanical properties can be secured. On the other hand, when the weight average molecular weight is 5 million or less, the shutdown characteristics are good and the film can be easily formed.
- the polyolefin microporous membrane can be produced, for example, by the following method. That is, (i) the molten polyolefin resin is extruded from a T-die to form a sheet, (ii) the sheet is crystallized, (iii) stretched, and (iv) the stretched sheet is heat treated. Thus, a method of forming a microporous film can be mentioned.
- a polyolefin resin is melted together with a plasticizer such as liquid paraffin, extruded from a T-die, cooled to form a sheet, (ii) the sheet is stretched, iii) A method of forming a microporous film by extracting a plasticizer from the stretched sheet and further (iv) heat-treating it may be mentioned.
- a plasticizer such as liquid paraffin
- porous sheet made of a fibrous material examples include polyesters such as polyethylene terephthalate; polyolefins such as polyethylene and polypropylene; heat-resistant polymers such as aromatic polyamide, polyimide, polyethersulfone, polysulfone, polyetherketone, and polyetherimide; And the like, or a porous sheet made of a mixture of the fibrous materials.
- a composite porous sheet the structure which laminated
- a composite porous sheet is preferable in that a further function can be added by the functional layer.
- the functional layer for example, from the viewpoint of imparting heat resistance, a porous layer made of a heat resistant resin or a porous layer made of a heat resistant resin and an inorganic filler can be adopted.
- the heat resistant resin include one or more heat resistant polymers selected from aromatic polyamide, polyimide, polyethersulfone, polysulfone, polyetherketone and polyetherimide.
- a metal oxide such as alumina or a metal hydroxide such as magnesium hydroxide can be suitably used.
- a method of applying a functional layer to a microporous membrane or a porous sheet a method of bonding the microporous membrane or porous sheet and the functional layer with an adhesive, a microporous membrane or a porous layer Examples thereof include a method of thermocompression bonding the sheet and the functional layer.
- the puncture strength As described above, from the viewpoint of adjusting the ratio of the standard deviation of the basis weight of the adhesive resin to the average value of the basis weight of the adhesive resin to a range of 0.3 or less, for example, the elongation of the porous substrate, the puncture strength The tensile strength and Young's modulus are preferably adjusted to the following ranges.
- the elongation in the MD direction or TD direction of the porous substrate is preferably 50% or more and 200% or less.
- the lower limit is more preferably 80% or more, still more preferably 100% or more.
- the upper limit is preferably 180% or less, more preferably 150% or less.
- the puncture strength of the porous substrate is preferably 200 g or more and 800 g or less.
- the lower limit is more preferably 250 g or more, and still more preferably 300 g or more.
- the upper limit is preferably 700 g or less, more preferably 600 g or less.
- the tensile strength in the MD direction or TD direction of the porous substrate is preferably 1 N / cm or more and 25 N / cm or less.
- the lower limit is more preferably 3 N / cm or more, and further preferably 5 N / cm or more.
- the upper limit is preferably 22 N / cm or less, more preferably 20 N / cm or less.
- the Young's modulus of the porous substrate is preferably 800 MPa or more and 5000 MPa or less.
- the lower limit is more preferably 900 MPa or more, and still more preferably 1000 MPa or more.
- the upper limit is preferably 4000 MPa or less, and preferably 3000 MPa or less.
- the Young's modulus is the amount of elastic deformation when a force is applied within the range showing elasticity, that is, the stress required per unit strain. For example, a stress-strain curve in which the vertical axis is stressed and the horizontal axis is strained This corresponds to the inclination of the straight line portion.
- the film thickness (average value) of the porous substrate is preferably in the range of 5 ⁇ m to 25 ⁇ m from the viewpoint of obtaining good mechanical properties and internal resistance.
- the Gurley value (JIS P8117) of the porous substrate is preferably in the range of 50 seconds / 100 cc to 800 seconds / 100 cc from the viewpoint of preventing short circuit of the battery and obtaining sufficient ion permeability.
- the adhesive porous layer in the present invention has a large number of micropores inside and has a porous structure in which these micropores are connected to each other, allowing gas or liquid to pass from one surface to the other. It is the layer that became.
- the porous structure of the adhesive porous layer is an important technical element.
- the adhesive porous layer is provided as the outermost layer of the separator on one side or both sides of the porous substrate, and can be adhered to the electrode by this adhesive porous layer. That is, the adhesive porous layer is a layer that can adhere the separator to the electrode when hot-pressed with the separator and the electrode overlapped.
- the separator for nonaqueous electrolyte batteries of the present invention has an adhesive porous layer only on one side of the porous substrate, the adhesive porous layer is bonded to either the positive electrode or the negative electrode.
- the separator for nonaqueous electrolyte batteries of this invention has an adhesive porous layer on both sides of the said porous base material, an adhesive porous layer is adhere
- the adhesive porous layer is preferable not only on one side of the porous base material but also on both sides in terms of excellent battery cycle characteristics. This is because the adhesive porous layer is on both surfaces of the porous substrate, so that both surfaces of the separator are well bonded to both electrodes via the adhesive porous layer.
- the coating amount (average weight per unit area) of the adhesive porous layer is the amount on one side of the porous substrate.
- 0.5 g / m 2 to 1.5 g / m 2 is preferable, and 0.7 g / m 2 to 1.3 g / m 2 is more preferable.
- the coating amount is 0.5 g / m 2 or more, the adhesion with the electrode is also improved. Thus, the cycle characteristics of the battery are excellent.
- the coating amount is 1.5 g / m 2 or less, it is easy to suppress variation in the coating amount of the adhesive porous layer within the aforementioned range, and good ion permeability is ensured, and the load on the battery is reduced. Good characteristics.
- the difference between the coating amount on one side and the coating amount on the other side is 20% with respect to the total coating amount on both sides.
- the following is preferable. If it is 20% or less, the separator is difficult to curl. As a result, the handling property is good and the problem that the cycle characteristics are deteriorated hardly occurs.
- the thickness of the adhesive porous layer is preferably 0.3 ⁇ m to 5 ⁇ m on one side of the porous substrate.
- the thickness is 0.3 ⁇ m or more, the coating amount variation of the adhesive porous layer can be easily suppressed within the above-described range, and the adhesiveness to the electrode becomes better. Thus, the cycle characteristics of the battery are good.
- the thickness is 5 ⁇ m or less, better ion permeability is ensured and the load characteristics of the battery are excellent.
- the thickness of the adhesive porous layer is more preferably 0.5 ⁇ m to 5 ⁇ m, still more preferably 1 ⁇ m to 2 ⁇ m on one side of the porous substrate.
- the adhesive porous layer preferably has a sufficiently porous structure from the viewpoint of ion permeability.
- the porosity is preferably 30% to 60%.
- the porosity is 30% or more, the ion permeability is good and the battery characteristics are more excellent.
- the porosity is 60% or less, sufficient mechanical properties are obtained such that the porous structure is not crushed when bonded to the electrode by hot pressing.
- the porosity is 60% or less, the surface porosity becomes low, and the area occupied by the adhesive resin (preferably polyvinylidene fluoride resin) increases, so that a better adhesive force can be secured. it can.
- the porosity of the adhesive porous layer is more preferably in the range of 30 to 50%.
- the adhesive porous layer preferably has an average pore size of 1 nm to 100 nm.
- the average pore size of the adhesive porous layer is 100 nm or less, a porous structure in which uniform pores are uniformly dispersed can be easily obtained, and the adhesion points with the electrode can be evenly dispersed. Sex is obtained. In that case, the movement of ions is also uniform, better cycle characteristics can be obtained, and better load characteristics can be obtained.
- the average pore diameter is desirably as small as possible from the viewpoint of uniformity, but it is practically difficult to form a porous structure smaller than 1 nm.
- the resin for example, polyvinylidene fluoride resin
- the resin may swell. If the average pore diameter is too small, the pores are blocked by swelling and the ion permeability is impaired. It is. From this point of view.
- the average pore diameter is preferably 1 nm or more.
- the average pore size of the adhesive porous layer is more preferably 20 nm to 100 nm.
- the fibril diameter of the polyvinylidene fluoride resin in the adhesive porous layer is preferably in the range of 10 nm to 1000 nm from the viewpoint of cycle characteristics.
- the adhesive porous layer in the present invention contains at least an adhesive resin, and preferably contains a filler. Moreover, the adhesive porous layer can be constituted by using other components as required.
- the adhesive resin contained in the adhesive porous layer is not particularly limited as long as it can adhere to the electrode.
- the adhesive porous layer may contain only one type of adhesive resin or two or more types.
- the adhesive resin is preferably a polyvinylidene fluoride resin from the viewpoint of adhesiveness with the electrode.
- the polyvinylidene fluoride resin a homopolymer of vinylidene fluoride (that is, polyvinylidene fluoride); a copolymer of vinylidene fluoride and another copolymerizable monomer (polyvinylidene fluoride copolymer); a mixture thereof ;
- the monomer copolymerizable with vinylidene fluoride include tetrafluoroethylene, hexafluoropropylene (HFP), trifluoroethylene, trichloroethylene, vinyl fluoride, and the like, and one kind or two or more kinds can be used.
- the polyvinylidene fluoride resin is obtained by emulsion polymerization or suspension polymerization.
- a copolymer obtained by copolymerizing at least vinylidene fluoride and hexafluoropropylene is preferable from the viewpoint of adhesion to an electrode, and moreover, a structural unit derived from vinylidene fluoride and a mass standard And more preferably 0.1 to 5 mol% (preferably 0.5 to 2 mol%) of a hexafluoropropylene-derived structural unit.
- the polyvinylidene fluoride resin preferably contains a resin containing 98 mol% or more of vinylidene fluoride as a structural unit. When 98 mol% or more of vinylidene fluoride is contained, sufficient mechanical properties and heat resistance can be ensured even under severe hot press conditions.
- the adhesive resin preferably has a weight average molecular weight (Mw) in the range of 600,000 to 3,000,000.
- Mw weight average molecular weight
- the lower limit of the weight average molecular weight is more preferably 700,000 or more, and even more preferably 800,000 or more.
- the upper limit of the weight average molecular weight is preferably 2 million or less, and more preferably 1.5 million or less.
- the weight average molecular weight (Dalton) of the adhesive resin is a molecular weight measured by gel permeation chromatography (hereinafter also referred to as GPC) under the following conditions and expressed in terms of polystyrene.
- GPC gel permeation chromatography
- the degree of swelling of the resin contained in the adhesive porous layer varies depending on the type of resin and the composition of the electrolytic solution.
- a polyvinylidene fluoride-based resin containing a large amount of a copolymer component tends to swell, whereas a polyvinylidene fluoride-based resin containing 98 mol% or more of vinylidene fluoride is less likely to swell.
- Polyvinylidene fluoride-based resins have a high cyclic carbonate content such as ethylene carbonate and propylene carbonate, and are likely to swell in electrolytes having a high dielectric constant. Polyvinylidene fluoride-based resins containing 98 mol% or more of vinylidene fluoride are It is suitable because it is relatively difficult to swell.
- the adhesive porous layer may contain a filler made of an inorganic material or an organic material.
- the adhesive porous layer contains a filler, the slipperiness and heat resistance of the separator are improved.
- the inorganic filler include metal oxides such as alumina and metal hydroxides such as magnesium hydroxide.
- an organic filler an acrylic resin etc. are mentioned, for example.
- the mass ratio of the filler to the adhesive resin is preferably 0.01 or more and 0.05 or less.
- the separator for a nonaqueous electrolyte battery of the present invention preferably has a total film thickness of 5 ⁇ m to 35 ⁇ m from the viewpoint of mechanical strength and energy density when used as a battery.
- the porosity of the separator for a nonaqueous electrolyte battery of the present invention is preferably 30% to 60% from the viewpoint of mechanical strength, handling properties, and ion permeability.
- the Gurley value (JIS P8117) of the nonaqueous electrolyte battery separator of the present invention is preferably 50 seconds / 100 cc to 800 seconds / 100 cc from the viewpoint of a good balance between mechanical strength and membrane resistance.
- the separator for a nonaqueous electrolyte battery of the present invention has a difference between the Gurley value of the porous substrate and the Gurley value of the separator provided with the adhesive porous layer on the porous substrate from the viewpoint of ion permeability. 300 seconds / 100 cc or less, more preferably 150 seconds / 100 cc or less, and even more preferably 100 seconds / 100 cc or less.
- Membrane resistance of the separator for a nonaqueous electrolyte battery of the present invention from the viewpoint of the load characteristics of the battery, it is preferable that 1ohm ⁇ cm 2 ⁇ 10ohm ⁇ cm 2.
- the membrane resistance is a resistance value when the separator is impregnated with an electrolytic solution, and is measured by an alternating current method.
- the above numerical values are values measured at 20 ° C. using 1 M LiBF 4 -propylene carbonate / ethylene carbonate (mass ratio 1/1) as the electrolytic solution.
- the curvature of the separator for a nonaqueous electrolyte battery of the present invention is preferably 1.5 to 2.5 from the viewpoint of ion permeability.
- the separator for a non-aqueous electrolyte battery of the present invention is formed by, for example, applying a coating liquid containing an adhesive resin such as a polyvinylidene fluoride resin on a porous substrate to form a coating layer. It is manufactured by a method in which the adhesive porous layer is integrally formed on the porous substrate by solidifying the resin.
- an adhesive porous layer is formed using a polyvinylidene fluoride resin will be described.
- the adhesive porous layer using the polyvinylidene fluoride resin as the adhesive resin can be suitably formed by, for example, the following wet coating method.
- the wet coating method includes (i) a step of dissolving a polyvinylidene fluoride resin in an appropriate solvent to prepare a coating solution, (ii) a step of applying this coating solution to a porous substrate, (iii) By immersing the porous base material in an appropriate coagulating liquid, a step of solidifying the polyvinylidene fluoride resin while inducing phase separation, (iv) a water washing step, and (v) a drying step are performed to obtain a porous material.
- This is a film forming method for forming a porous layer on a substrate.
- the details of the wet coating method suitable for the present invention are as follows.
- Solvents for dissolving the polyvinylidene fluoride resin used for preparing the coating liquid include polar amide solvents such as N-methylpyrrolidone, dimethylacetamide, dimethylformamide, and dimethylformamide. Preferably used. From the viewpoint of forming a good porous structure, it is preferable to mix a phase separation agent that induces phase separation in addition to a good solvent. Examples of the phase separation agent include water, methanol, ethanol, propyl alcohol, butyl alcohol, butanediol, ethylene glycol, propylene glycol, and tripropylene glycol.
- the phase separation agent is preferably added in a range that can ensure a viscosity suitable for coating.
- the solvent is preferably a mixed solvent containing 60% by mass or more of a good solvent and 40% by mass or less of a phase separation agent from the viewpoint of forming a good porous structure.
- the coating liquid preferably contains a polyvinylidene fluoride resin at a concentration of 3% by mass to 10% by mass from the viewpoint of forming a good porous structure. What is necessary is just to mix or dissolve in a coating liquid, when making an adhesive porous layer contain a filler and another component.
- the coagulation liquid is generally composed of a good solvent used for preparing the coating liquid, a phase separation agent, and water. It is preferable in production that the mixing ratio of the good solvent and the phase separation agent is adjusted to the mixing ratio of the mixed solvent used for dissolving the polyvinylidene fluoride resin.
- the water concentration is suitably 40% by mass to 90% by mass from the viewpoint of formation of a porous structure and productivity.
- the conventional coating method such as Meyer bar, die coater, reverse roll coater or gravure coater may be applied to the coating liquid on the porous substrate.
- the adhesive porous layer is formed on both surfaces of the porous substrate, it is preferable from the viewpoint of productivity to apply the coating liquid to both surfaces simultaneously on both surfaces.
- the adhesive porous layer can be produced by a dry coating method other than the wet coating method described above.
- the dry coating method refers to, for example, coating a porous substrate with a coating liquid containing a polyvinylidene fluoride resin and a solvent, and drying the coating layer to volatilize and remove the solvent. It is a method of obtaining a layer.
- the wet coating method is preferred in that a good porous structure can be obtained.
- the separator for a non-aqueous electrolyte battery of the present invention is produced by a method in which an adhesive porous layer is produced as an independent sheet, and this adhesive porous layer is laminated on a porous substrate and combined by thermocompression bonding or an adhesive. Can also be manufactured.
- a method for producing the adhesive porous layer as an independent sheet a coating liquid containing a resin is applied onto a release sheet, and the above-mentioned wet coating method or dry coating method is applied to form the adhesive porous layer.
- the method of forming and peeling an adhesive porous layer from a peeling sheet is mentioned.
- the non-aqueous electrolyte battery of the present invention is a non-aqueous electrolyte battery that obtains an electromotive force by doping or dedoping lithium, and includes a positive electrode, a negative electrode, and the separator for a non-aqueous electrolyte battery of the present invention described above.
- the dope means occlusion, support, adsorption, or insertion, and means a phenomenon in which lithium ions enter the active material of an electrode such as a positive electrode.
- the nonaqueous electrolyte battery has a structure in which a battery element in which a negative electrode and a positive electrode face each other with a separator interposed therebetween is impregnated with an electrolytic solution.
- the nonaqueous electrolyte battery of the present invention is suitable for a nonaqueous electrolyte secondary battery, particularly a lithium ion secondary battery.
- the nonaqueous electrolyte battery of the present invention is provided with the above-described separator for nonaqueous electrolyte batteries of the present invention as a separator, so that the adhesiveness between the electrode and the separator is excellent, and the yield in the manufacturing process is high. It also has excellent retention. Therefore, the nonaqueous electrolyte battery of the present invention exhibits stable cycle characteristics.
- the positive electrode can have a structure in which an active material layer containing a positive electrode active material and a binder resin is formed on a current collector.
- the active material layer may further contain a conductive additive.
- the positive electrode active material include lithium-containing transition metal oxides. Specifically, LiCoO 2 , LiNiO 2 , LiMn 1/2 Ni 1/2 O 2 , LiCo 1/3 Mn 1/3 Ni 1 / 3 O 2, LiMn 2 O 4 , LiFePO 4, LiCo 1/2 Ni 1/2 O 2, LiAl 1/4 Ni 3/4 O 2 and the like.
- the binder resin include polyvinylidene fluoride resins and styrene-butadiene copolymers.
- the conductive aid include carbon materials such as acetylene black, ketjen black, and graphite powder.
- the current collector include aluminum foil, titanium foil, and stainless steel foil having a thickness of 5 ⁇ m to 20 ⁇ m.
- the separator when the separator includes an adhesive porous layer containing a polyvinylidene fluoride resin, and the adhesive porous layer is disposed on the positive electrode side, the polyvinylidene fluoride resin has oxidation resistance. Since it is excellent, it is easy to apply positive electrode active materials such as LiMn 1/2 Ni 1/2 O 2 and LiCo 1/3 Mn 1/3 Ni 1/3 O 2 that can be operated at a high voltage of 4.2 V or more. is there.
- the negative electrode may have a structure in which an active material layer including a negative electrode active material and a binder resin is formed on a current collector.
- the active material layer may further contain a conductive additive.
- the negative electrode active material include materials that can occlude lithium electrochemically, and specifically include carbon materials, silicon, tin, aluminum, wood alloys, and the like.
- the binder resin include polyvinylidene fluoride resins and styrene-butadiene copolymers.
- the conductive aid include carbon materials such as acetylene black, ketjen black, and graphite powder.
- Examples of the current collector include copper foil, nickel foil, and stainless steel foil having a thickness of 5 ⁇ m to 20 ⁇ m. Moreover, it may replace with said negative electrode and may use metal lithium foil as a negative electrode.
- the electrolytic solution is a solution in which a lithium salt is dissolved in a non-aqueous solvent.
- the lithium salt include LiPF 6 , LiBF 4 , LiClO 4, and the like.
- non-aqueous solvents include cyclic carbonates such as ethylene carbonate, propylene carbonate, fluoroethylene carbonate, and difluoroethylene carbonate; chain carbonates such as dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, and fluorine-substituted products thereof; ⁇ -butyrolactone And cyclic esters such as ⁇ -valerolactone, and these may be used alone or in combination.
- a solution in which a cyclic carbonate and a chain carbonate are mixed at a mass ratio (cyclic carbonate / chain carbonate) of 20/80 to 40/60 and a lithium salt is dissolved in an amount of 0.5 M to 1.5 M is preferable. is there.
- Examples of the exterior material include a metal can and a pack made of an aluminum laminate film.
- the shape of the battery includes a square shape, a cylindrical shape, a coin shape, and the like, but the nonaqueous electrolyte battery separator of the present invention is suitable for any shape.
- the thickness of the separator or porous substrate was measured as follows. First, a separator or a porous substrate was cut into a size of 10 cm ⁇ 10 cm, and 10 sample pieces were prepared. For each sample piece, the thickness of the central part in the width direction (TD) was measured 10 points at 1 cm intervals in the length direction (MD) to obtain a total of 100 points of thickness data. Then, an average value and a standard deviation were calculated based on the thickness data of 100 points.
- a contact-type thickness meter for example, LITEMASIC manufactured by Mitutoyo Corporation
- a cylindrical terminal having a diameter of 5 mm was used for the measurement terminal, and the load was adjusted so that a load of 7 g was applied during the measurement.
- the ratio of the standard deviation of the basis weight of the adhesive porous layer to the average value of the basis weight of the adhesive porous layer is the basis weight (g / m 2 ) of the adhesive porous layer determined as described above. Obtained by dividing the standard deviation by the mean value.
- the ratio (thickness variation) of the standard deviation of the thickness of the porous substrate to the average value of the thickness of the porous substrate is the average value of the thickness (g / m 2 ) of the porous substrate determined as described above. Calculated using standard deviation.
- the tensile strength of the porous substrate or the separator was adjusted to 10 mm ⁇ 100 mm using a tensile tester (ATC, manufactured by A & D, RTC-1225A), the load cell load was 5 kgf, the distance between chucks was 50 mm, and the tensile speed was 100 mm / min. Measured under the conditions, the stress at break was taken as the tensile strength.
- ATC tensile tester
- Young's modulus The Young's modulus of the porous substrate or separator was adjusted to 10 mm ⁇ 100 mm using a tensile tester (manufactured by A & D, RTC-1225A), using a load cell load of 5 kgf, a distance between chucks of 50 mm, and a tensile speed of 100 mm / min. Under the conditions, Young's modulus was measured with reference to JIS K 7161.
- the puncture strength of the porous substrate or separator is determined by holding the sample in a metal frame (sample holder) with a hole of ⁇ 11.3 mm together with a silicone rubber packing, and fixing the KES-G5 handy compression tester (Kato Tech). The measurement was performed using The measurement conditions were a radius of curvature of the needle tip of 0.5 mm and a puncture speed of 2 mm / sec. The maximum puncture load was defined as the puncture strength.
- the test battery produced below was repeatedly charged and discharged at a charge voltage of 4.2 V and a discharge voltage of 2.75 V, the discharge capacity at the 100th cycle was divided by the initial capacity, and the capacity was maintained when charge and discharge were repeated.
- the average value and the fluctuation range (%) of the rate were evaluated as cycle characteristics.
- the evaluation criteria were as follows. A: When the capacity retention rate is 85% or more and the fluctuation range is 7% or less B: When the capacity retention rate is 85% or more but the fluctuation range exceeds 7% C: The capacity retention rate is less than 85%, When the fluctuation range exceeds 7%
- the test battery was disassembled, and the magnitude of the force when the negative electrode and the positive electrode were peeled off from the separator was measured using a tensile tester (manufactured by A & D, RTC-1225A). Evaluation was made as an index when the magnitude of the force in Example 1 was 100. An index of 80 or higher is a practically preferable level.
- the separator is conveyed at a conveyance speed of 40 m / min, unwinding tension: 0.3 N / cm, winding tension: 0.1 N / cm, and applied horizontally at a 60 ° angle with a stainless steel leather blade.
- the members that were dropped during the slitting process and those that were visually observed for the appearance of the end face (slit end face) were counted.
- ⁇ Evaluation criteria> A: The number of chips derived from the adhesive porous layer of 0.5 mm or more is 5 or less.
- B The number of chips derived from the adhesive porous layer of 0.5 mm or more is 10 or less.
- C The number of chips derived from the adhesive porous layer of 0.5 mm or more is 20 or less.
- D There are 20 or more chips derived from the adhesive porous layer of 0.5 mm or more.
- a working solution was prepared.
- a polyethylene microporous film (thickness: 9 ⁇ m, Gurley value: 160 sec / 100 cc, porosity: 43%) was used.
- An equal amount of the coating solution obtained as described above was applied to both sides of a polyethylene microporous membrane.
- Example 4 In Example 1, a separator was prepared in the same manner as in Example 1 except that a polyethylene microporous film having physical properties shown in Table 1 below was used as the porous substrate. Secondary battery).
- Example 7 and 8 In Example 1, Examples 7 and 8 were carried out in the same manner as Example 1 except that a vinylidene fluoride / hexafluoropropylene copolymer having a weight average molecular weight of 600,000 or 3 million was used as the adhesive resin. A separator battery (lithium ion secondary battery) was prepared.
- Example 2 separators of Comparative Examples 2 to 5 were prepared in the same manner as in Example 1 except that a polyethylene microporous film having physical properties shown in Table 1 below was used as the porous substrate.
- a test battery lithium ion secondary battery
- Example 9 As shown in Table 1, in the examples, by setting the “standard deviation of basis weight / average value of basis weight” of the adhesive porous layer within a predetermined range, the adhesiveness with the electrode is excellent as compared with the comparative example. Good cycle characteristics were exhibited, and the slit property was also good. In addition, the evaluation result comparable to Example 1 was obtained also about Example 9.
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Cell Separators (AREA)
- Secondary Cells (AREA)
Abstract
Description
<1> 多孔質基材と、前記多孔質基材の片面又は両面に設けられ、接着性樹脂を含む接着性多孔質層とを有し、前記接着性多孔質層の目付の平均値(g/m2)に対する前記接着性多孔質層の目付の標準偏差の比(標準偏差/平均値)が0.3以下である、非水電解質電池用セパレータ。
<2> 前記多孔質基材の厚みの平均値(μm)に対する多孔質基材の厚みの標準偏差の比(標準偏差/平均値)が、0.02以下である<1>に記載の非水電解質電池用セパレータ。
<3> 前記接着性樹脂は、ポリフッ化ビニリデン系樹脂である<1>又は<2>に記載の非水電解質電池用セパレータ。
<4> 前記ポリフッ化ビニリデン系樹脂の重量平均分子量は、60万以上300万以下である、<3>に記載の非水電解質電池用セパレータ。
<5> 前記多孔質基材のMD方向あるいはTD方向の伸度が50%以上200%以下である、<1>~<4>のいずれか1項に記載の非水電解質電池用セパレータ。
<6> 前記多孔質基材の突刺強度が200g以上800g以下である、<1>~<5>のいずれか1項に記載の非水電解質電池用セパレータ。
<7> 前記接着性多孔質層にはフィラーが含まれており、前記フィラーの前記接着性樹脂に対する質量比(フィラーの質量/接着性樹脂の質量)が0.01以上0.05以下である、<1>~<6>のいずれか1項に記載の非水電解質電池用セパレータ。
<8> 正極と、負極と、前記正極及び前記負極の間に配置された<1>~<7>のいずれか1項に記載の非水電解質電池用セパレータとを備え、リチウムのドープ・脱ドープにより起電力を得る非水電解質電池。
本発明の非水電解質電池用セパレータは、多孔質基材と、多孔質基材の片面又は両面に設けられ、接着性樹脂を含む接着性多孔質層とを設け、接着性多孔質層の目付の平均値[g/m2]に対する接着性多孔質層の目付の標準偏差の比(標準偏差/平均値)を0.3以下として構成されている。
なお、接着性多孔質層又は接着性樹脂の目付(g/m2)とは、接着性多孔質層を塗工により設けた場合に、その乾燥後の塗工量(g/m2)を表す。
接着性多孔質層の目付は、以下のように測定される。すなわち、まず、セパレータを10cm×10cmサイズに切り出したサンプル片を10枚用意し、各サンプル片の目付を測定する。続いて、各サンプル片に設けられている接着性多孔質層(塗工層)を溶剤で溶解除去し、それぞれの多孔質基材の目付を測定する。その後、セパレータの目付から多孔質基材の目付を減算することで、各サンプル片の接着性多孔質層の目付が求められる。
すなわち、N個のデータx1, x2, ..., xNからなる母集団がある場合に、「平均値」は下記式に示されるように、その母集団の相加平均(母平均m)として定義される。つまり、本発明において、接着性多孔質層の目付の平均値は、あるセパレータについて測定した10点の目付の値を合計し、それを10で除算することで求められる。
多孔質基材の厚みは、以下のように測定される。すなわち、多孔質基材を10cm×10cmサイズに切り出し、サンプル片を10枚用意した。各サンプル片に対して、幅方向(TD)の中央部を、長さ方向(MD)に1cm間隔で10点ずつ厚みを測定し、合計100点の厚みデータを得る。そして、この100点の厚みデータに基づき、上記目付の場合と同様にして、平均値および標準偏差を算出する。厚みの測定には、接触式の厚み計(例えばミツトヨ社製LITEMATIC)を用い、測定端子には直径5mmの円柱状のものを用い、測定中に7gの荷重が印加されるように調整する。
「(厚みの標準偏差)/(厚みの平均値)」で表される比は、0.01以下がより好ましく、0.005以下が更に好ましく、ゼロ(バラツキのないこと)が理想的である。
多孔質基材の厚みのバラツキを制御する手法としては特に限定されるものではない。例えば、市販の多孔質基材で上述した厚みの条件を満足するものを選定すればよい。
本発明における多孔質基材は、内部に空孔ないし空隙を有する基材を意味する。このような基材としては、微多孔膜や、不織布、紙状シート等の繊維状物からなる多孔性シート、あるいは、これら微多孔膜や多孔性シートに他の多孔性層を1層以上積層した複合多孔質シート等が挙げられる。
前記熱可塑性樹脂としては、融点200℃未満の熱可塑性樹脂が適当であり、特にポリオレフィンが好ましい。
ポリオレフィン微多孔膜としては、従来の非水電解質電池用セパレータに適用されているポリオレフィン微多孔膜の中から、充分な力学物性とイオン透過性を有するものを好適に用いることができる。
ポリオレフィン微多孔膜は、シャットダウン機能を発現する観点から、ポリエチレンを含むことが好ましく、ポリエチレンの含有量としては95質量%以上が好ましい。
なお、複合化の手法としては、微多孔膜や多孔性シートに機能層を塗工する方法、微多孔膜や多孔性シートと機能層とを接着剤で接合する方法、微多孔膜や多孔性シートと機能層とを熱圧着する方法等が挙げられる。
ヤング率は、弾性を示す範囲で力を加えたときに弾性変形する量、すなわち単位歪みあたりに必要とされる応力であり、例えば縦軸を応力とし横軸を歪みとして引いた応力-歪み曲線の直線部の傾きに相当する。ヤング率は、一方向に引張り又は圧縮させた際の応力の方向に対する歪み量の関係から、下記式から求められる。
E=σ/ε 〔E:ヤング率、σ:歪み、ε:応力〕
多孔質基材のガーレ値(JIS P8117)としては、電池の短絡防止や充分なイオン透過性を得る観点から、50秒/100cc以上800秒/100cc以下の範囲が好適である。
本発明における接着性多孔質層は、内部に多数の微細孔を有し、これら微細孔が互いに連結された多孔構造となっており、一方の面から他方の面へと気体あるいは液体が通過可能となった層である。接着性多孔質層の多孔構造は重要な技術要素である。
接着性多孔質層の平均孔径としては、20nm~100nmがより好ましい。
接着性多孔質層に含まれる接着性樹脂は、電極と接着し得るものであれば特に制限されない。例えば、ポリフッ化ビニリデン、ポリフッ化ビニリデン共重合体、スチレン-ブタジエン共重合体、アクリロニトリル、メタクリロニトリル等のビニルニトリル類の単独重合体又は共重合体、ポリエチレンオキサイド、ポリプロピレンオキサイド等のポリエーテルが好適である。
接着性多孔質層は、接着性樹脂を1種のみ含んでもよく、2種以上を含んでもよい。
ポリフッ化ビニリデン系樹脂としては、フッ化ビニリデンの単独重合体(即ちポリフッ化ビニリデン);フッ化ビニリデンと他の共重合可能なモノマーとの共重合体(ポリフッ化ビニリデン共重合体);これらの混合物;が挙げられる。
フッ化ビニリデンと共重合可能なモノマーとしては、例えば、テトラフロロエチレン、ヘキサフロロプロピレン(HFP)、トリフロロエチレン、トリクロロエチレン、フッ化ビニル等が挙げられ、1種類又は2種類以上を用いることができる。
ポリフッ化ビニリデン系樹脂は、乳化重合または懸濁重合により得られる。
<条件>
・GPC:Alliance GPC 2000型〔Waters社製〕
・カラム:TSKgel GMH6-HT×2 +TSKgel GMH6-HTL×2〔東ソー(株)製〕
・移動相溶媒:o-ジクロロベンゼン
・標準試料 :単分散ポリスチレン〔東ソー(株)製〕
・カラム温度:140℃
また、ポリフッ化ビニリデン系樹脂は、例えばエチレンカーボネートやプロピレンカーボネートといった環状カーボネートの含有量が高く誘電率の高い電解液に膨潤しやすいが、フッ化ビニリデンを98モル%以上含むポリフッ化ビニリデン系樹脂は比較的膨潤しにくいので好適である。
接着性多孔質層は、無機物又は有機物からなるフィラーを含有していてもよい。接着性多孔質層がフィラーを含むことで、セパレータの滑り性や耐熱性が向上する。
無機フィラーとしては、例えば、アルミナ等の金属酸化物、水酸化マグネシウム等の金属水酸化物等が挙げられる。また、有機フィラーとしては、例えばアクリル樹脂等が挙げられる。
フィラーの前記接着性樹脂に対する質量比(フィラーの質量/接着性樹脂の質量)は、0.01以上0.05以下であることが好ましい。このようにフィラーの含有量を調整することで、接着性多孔質層の「(目付の標準偏差)/(目付の平均値)」で表される値を本発明の範囲内に調整しやすくなる。
本発明の非水電解質電池用セパレータは、機械強度と電池としたときのエネルギー密度の観点から、全体の膜厚が5μm~35μmであることが好ましい。
本発明の非水電解質電池用セパレータは、イオン透過性の観点から、多孔質基材のガーレ値と、前記多孔質基材上に接着性多孔質層を設けたセパレータのガーレ値との差が、300秒/100cc以下であることが好ましく、150秒/100cc以下であることがより好ましく、100秒/100cc以下であることが更に好ましい。
本発明の非水電解質電池用セパレータは、例えば、ポリフッ化ビニリデン系樹脂等の接着性樹脂を含む塗工液を多孔質基材上に塗工し塗工層を形成し、次いで塗工層の樹脂を固化させることで、接着性多孔質層を多孔質基材上に一体的に形成する方法で製造される。
以下、接着性多孔質層をポリフッ化ビニリデン系樹脂を用いて形成する場合について、説明する。
湿式塗工法は、(i)ポリフッ化ビニリデン系樹脂を適切な溶媒に溶解させて塗工液を調製する工程、(ii)この塗工液を多孔質基材に塗工する工程、(iii)当該多孔質基材を適切な凝固液に浸漬させることで、相分離を誘発しつつポリフッ化ビニリデン系樹脂を固化させる工程、(iv)水洗工程、および(v)乾燥工程を行って、多孔質基材上に多孔質層を形成する製膜法である。本発明に好適な湿式塗工法の詳細は、以下のとおりである。
良好な多孔構造を形成する観点からは、良溶媒に加えて相分離を誘発させる相分離剤を混合させることが好ましい。相分離剤としては、水、メタノール、エタノール、プロピルアルコール、ブチルアルコール、ブタンジオール、エチレングリコール、プロピレングリコール、トリプロピレングリコール等が挙げられる。相分離剤は、塗工に適切な粘度が確保できる範囲で添加することが好ましい。
溶媒としては、良好な多孔構造を形成する観点から、良溶媒を60質量%以上、相分離剤を40質量%以下含む混合溶媒が好ましい。
接着性多孔質層にフィラーやその他の成分を含有させる場合は、塗工液中に混合あるいは溶解させればよい。
本発明の非水電解質電池は、リチウムのドープ・脱ドープにより起電力を得る非水電解質電池であり、正極と、負極と、既述の本発明の非水電解質電池用セパレータとを設けて構成されている。なお、ドープとは、吸蔵、担持、吸着、又は挿入を意味し、正極等の電極の活物質にリチウムイオンが入る現象を意味する。
正極活物質としては、例えばリチウム含有遷移金属酸化物等が挙げられ、具体的にはLiCoO2、LiNiO2、LiMn1/2Ni1/2O2、LiCo1/3Mn1/3Ni1/3O2、LiMn2O4、LiFePO4、LiCo1/2Ni1/2O2、LiAl1/4Ni3/4O2等が挙げられる。
バインダー樹脂としては、例えば、ポリフッ化ビニリデン系樹脂、スチレン-ブタジエン共重合体などが挙げられる。
導電助剤としては、例えばアセチレンブラック、ケッチェンブラック、黒鉛粉末といった炭素材料が挙げられる。
集電体としては、例えば厚さ5μm~20μmの、アルミ箔、チタン箔、ステンレス箔等が挙げられる。
負極活物質としては、例えばリチウムを電気化学的に吸蔵し得る材料が挙げられ、具体的には炭素材料、シリコン、スズ、アルミニウム、ウッド合金等が挙げられる。
バインダー樹脂としては、例えば、ポリフッ化ビニリデン系樹脂、スチレン-ブタジエン共重合体などが挙げられる。
導電助剤としては、例えばアセチレンブラック、ケッチェンブラック、黒鉛粉末といった炭素材料が挙げられる。
集電体としては、例えば厚さ5μm~20μmの、銅箔、ニッケル箔、ステンレス箔等が挙げられる。
また、上記の負極に代えて、金属リチウム箔を負極として用いてもよい。
リチウム塩としては、例えばLiPF6、LiBF4、LiClO4等が挙げられる。
非水系溶媒としては、例えばエチレンカーボネート、プロピレンカーボネート、フロロエチレンカーボネート、ジフロロエチレンカーボネート等の環状カーボネート;ジメチルカーボネート、ジエチルカーボネート、エチルメチルカーボネート、及びそのフッ素置換体等の鎖状カーボネート;γ-ブチロラクトン、γ-バレロラクトン等の環状エステル;が挙げられ、これらは単独で用いても混合して用いてもよい。
電解液としては、環状カーボネートと鎖状カーボネートとを質量比(環状カーボネート/鎖状カーボネート)20/80~40/60で混合し、リチウム塩を0.5M~1.5M溶解したものが好適である。
電池の形状は角型、円筒型、コイン型等があるが、本発明の非水電解質電池用セパレータはいずれの形状にも好適である。
以下に示す実施例及び比較例で作製したセパレータ及びリチウムイオン二次電池について、以下の測定、評価を行なった。
セパレータあるいは多孔質基材の厚みは次の通り測定した。まず、セパレータあるいは多孔質基材を10cm×10cmサイズに切り出し、サンプル片を10枚用意した。各サンプル片に対して、幅方向(TD)の中央部を、長さ方向(MD)に1cm間隔で10点ずつ厚みを測定し、合計100点の厚みデータを得た。そして、この100点の厚みデータに基づき、平均値および標準偏差を算出した。厚みの測定には、接触式の厚み計(例えばミツトヨ社製LITEMATIC)を用い、測定端子には直径5mmの円柱状のものを用い、測定中に7gの荷重が印加されるように調整した。
セパレータを10cm×10cmサイズに切り出したサンプル片を10枚用意し、各サンプル片の質量を測定した。この質量を面積で除することにより、各セパレータの目付を求めた。続いて、各サンプル片に設けられている接着性多孔質層(塗工層)を溶剤で溶解除去し、多孔質基材の質量を測定した。この質量を面積で除することにより、多孔質基材の目付を求めた。その後、セパレータの目付から多孔質基材の目付を減算することで、各サンプル片の接着性多孔質層の目付を求めた。10点の接着性多孔質層の目付データに基づき、目付の平均値および標準偏差を算出した。
接着性多孔質層の目付の平均値に対する接着性多孔質層の目付の標準偏差の比(目付バラツキ)は、上記のようにして求めた接着性多孔質層の目付(g/m2)の標準偏差を平均値で除算して得た。
多孔質基材の厚みの平均値に対する多孔質基材の厚みの標準偏差の比(厚みバラツキ)は、上記のようにして求めた多孔質基材の厚み(g/m2)の平均値および標準偏差を用いて算出した。
多孔質基材あるいはセパレータの引張強度は、10mm×100mmに調整したサンプルを、引張試験機(A&D社製、RTC-1225A)を用い、ロードセル荷重5kgf、チャック間距離50mm、引張速度100mm/分の条件で測定し、破断時の応力を引張強度とした。
多孔質基材あるいはセパレータの引張伸度は、10mm×100mmに調整したサンプルを、引張試験機(A&D社製、RTC-1225A)を用い、ロードセル荷重5kgf、チャック間距離50mm、引張速度100mm/分の条件で測定し、破断時のチャック間距離を初期のチャック間距離50mmで除した値を伸度とした。
多孔質基材あるいはセパレータのヤング率は、10mm×100mmに調整したサンプルを、引張試験機(A&D社製、RTC-1225A)を用い、ロードセル荷重5kgf、チャック間距離50mm、引張速度100mm/分の条件において、JIS K 7161を参考にヤング率を測定した。
多孔質基材あるいはセパレータの突刺強度は、サンプルをφ11.3mmの穴があいた金枠(試料ホルダー)にシリコーンゴム製のパッキンと一緒に挟んで固定し、KES-G5ハンディー圧縮試験器(カトーテック社製)を用いて測定した。測定条件は、針先端の曲率半径を0.5mmとし、突刺速度を2mm/secとした。最大突刺荷重を突刺強度とした。
以下で作製した試験電池に対して、充電電圧4.2V、放電電圧2.75Vの充放電を繰返し、100サイクル目の放電容量を初期容量で除して、充放電を繰返したときの容量保持率の平均値及び変動幅(%)をサイクル特性として評価した。評価基準は以下の通りとした。
A:容量保持率が85%以上で、かつ変動幅が7%以下の場合
B:容量保持率が85%以上だが、変動幅が7%超の場合
C:容量保持率が85%未満で、かつ変動幅が7%を超える場合
試験電池を解体し、セパレータから負極と正極とをそれぞれ剥がす時の力の大きさを、引張試験機(A&D社製、RTC-1225A)を用いて測定した。実施例1における前記力の大きさを100としたときの指数として評価した。指数80上が実用的に好ましいレベルである。
セパレータを搬送速度:40m/min、巻き出し張力:0.3N/cm、巻取り張力:0.1N/cmにて搬送し、水平に搬送しながらステンレス製レザー刃60°の角度で当て、セパレータを1000mスリット処理した。このスリット工程中に脱落した部材、端面(スリット端面)の外観を目視により観察されるものを数えた。
<評価基準>
A:0.5mm以上の接着性多孔質層由来の切粉が5個以下である。
B:0.5mm以上の接着性多孔質層由来の切粉が10個以下である。
C:0.5mm以上の接着性多孔質層由来の切粉が20個以下である。
D:0.5mm以上の接着性多孔質層由来の切粉が20個以上である。
-セパレータの作製-
接着性樹脂として、フッ化ビニリデン/ヘキサフロロプロピレン共重合体(=98.9/1.1[モル比]、重量平均分子量:195万)を用いた。また、無機フィラーとして、平均粒子径0.8μmの水酸化マグネシウムを用い、無機フィラーのポリフッ化ビニリデン系樹脂に対する比率[質量比]を0.01(=無機フィラー/ポリフッ化ビニリデン系樹脂)とした。
多孔質基材として、ポリエチレン微多孔膜(厚さ:9μm、ガーレ値:160秒/100cc、空孔率:43%)を用いた。
上記のようにして得られた塗工液を、ポリエチレン微多孔膜の両面に等量塗工した。続いて、水とジメチルアセトアミドとトリプロピレングリコールとを混合した凝固液(=57/30/13[質量比])を用意し、この凝固液(40℃)に上記ポリエチレン微多孔膜を浸漬し、接着性樹脂を固化させた。
次に、水洗、乾燥させて、ポリオレフィン系微多孔膜の両面にポリフッ化ビニリデン系樹脂からなる接着性多孔質層が形成されたセパレータを得た。
このセパレータに関して、多孔質基材の物性(厚みの平均値、厚みの標準偏差/平均値、MD方向およびTD方向の伸度、突刺強度、MD方向およびTD方向の引張強度、ヤング率)、接着性多孔質層の物性(接着性樹脂の重量平均分子量(MW)、フィラー質量比(無機フィラーの質量/ポリフッ化ビニリデン系樹脂の質量)、接着性多孔質層(両面合計)の目付の平均値および標準偏差/平均値)、および、セパレータの物性(MD方向およびTD方向の伸度、突刺強度、MD方向およびTD方向の引張強度、ヤング率)を表1にまとめて示した。また、以下の実施例および比較例についても同様にまとめて表1に示した。
(1)負極の作製
負極活物質である人造黒鉛300g、バインダーであるスチレン-ブタジエン共重合体の変性体を40質量%含む水溶性分散液7.5g、増粘剤であるカルボキシメチルセルロース3g、及び適量の水を双腕式混合機にて攪拌し、負極用スラリーを作製した。この負極用スラリーを負極集電体である厚さ10μmの銅箔に塗布し、乾燥後プレスして、負極活物質層を有する負極を得た。
正極活物質であるコバルト酸リチウム粉末89.5g、導電助剤であるアセチレンブラック4.5g、及びバインダーであるポリフッ化ビニリデン6gを、ポリフッ化ビニリデンの濃度が6質量%となるようにN-メチル-ピロリドン(NMP)に溶解し、双腕式混合機にて攪拌し、正極用スラリーを作製した。この正極用スラリーを正極集電体である厚さ20μmのアルミ箔に塗布し、乾燥後プレスして、正極活物質層を有する正極を得た。
前記の正極と負極にリードタブを溶接した後、正極、セパレータ、および負極をこの順に重ねて接合し、電解液を染み込ませてアルミパック中に真空シーラーを用いて封入した。電解液には、エチレンカーボネート(EC)とエチルメチルカーボネート(DMC)とを3:7の質量比(=EC:DMC)で混合した1M LiPF6混合溶液を用いた。
電解液が封入されたアルミパックに対して、熱プレス機により電極1cm2当たり20kgの荷重をかけ、90℃、2分間の熱プレスを行なうことで、試験電池(リチウムイオン二次電池)を作製した。
実施例1において、無機フィラーのポリフッ化ビニリデン系樹脂に対する比率[質量比]を0.03(=無機フィラー/ポリフッ化ビニリデン系樹脂)とすることにより、ポリフッ化ビニリデン系樹脂からなる接着性多孔質層の「目付の標準偏差/目付の平均値」を下記表1に示す値に調節したこと以外は、実施例1と同様にして、セパレータを作製し、試験電池(リチウムイオン二次電池)を作製した。
実施例1において、無機フィラーのポリフッ化ビニリデン系樹脂に対する比率[質量比]を0.05(=無機フィラー/ポリフッ化ビニリデン系樹脂)とすることにより、ポリフッ化ビニリデン系樹脂からなる接着性多孔質層の「目付の標準偏差/目付の平均値」を下記表1に示す値に調節したこと以外は、実施例1と同様にして、セパレータを作製し、試験電池(リチウムイオン二次電池)を作製した。
実施例1において、多孔質基材として下記表1に示す物性値を有したポリエチレン微多孔膜を用いたこと以外は、実施例1と同様にして、セパレータを作製し、試験電池(リチウムイオン二次電池)を作製した。
実施例1において、多孔質基材として下記表1に示す物性値を有したポリエチレン微多孔膜を用い、無機フィラーのポリフッ化ビニリデン系樹脂に対する比率[質量比]を0.5(=無機フィラー/ポリフッ化ビニリデン系樹脂)にしたこと以外は、実施例1と同様にして、実施例5,6のセパレータを作製し、試験電池(リチウムイオン二次電池)を作製した。
実施例1において、接着性樹脂として、重量平均分子量が60万あるいは300万のフッ化ビニリデン/ヘキサフロロプロピレン共重合体を用いたこと以外は、実施例1と同様にして、実施例7,8のセパレータを作製し、試験電池(リチウムイオン二次電池)を作製した。
塗工液として、スチレン-ブタジエン共重合体及びカルボキシルメチルセルロースを含む塗布液(スチレン-ブタジエン共重合体:カルボキシルメチルセルロース:水=3:2:95[質量比])を用意し、これを実施例1と同様のポリエチレン微多孔膜の両面に等量塗工し、これを乾燥することで、スチレン-ブタジエン共重合体からなる接着性多孔質層が形成されたセパレータを得た。得られたセパレータにおける接着性多孔質層の目付は1.9g/m2であり、目付の標準偏差/平均値は0.19であった。
実施例1において、無機フィラーのポリフッ化ビニリデン系樹脂に対する比率[質量比]を0.10(=無機フィラー/ポリフッ化ビニリデン系樹脂)とすることにより、ポリフッ化ビニリデン系樹脂からなる接着性多孔質層の「目付の標準偏差/目付の平均値」を下記表1に示す値に調節したこと以外は、実施例1と同様にして、セパレータを作製し、試験電池(リチウムイオン二次電池)を作製した。
実施例1において、多孔質基材として下記表1に示す物性値を有したポリエチレン微多孔膜を用いたこと以外は、実施例1と同様にして、比較例2~5のセパレータを作製し、試験電池(リチウムイオン二次電池)を作製した。
Claims (8)
- 多孔質基材と、前記多孔質基材の片面又は両面に設けられ、接着性樹脂を含む接着性多孔質層とを有し、
前記接着性多孔質層の目付の平均値(g/m2)に対する前記接着性多孔質層の目付の標準偏差の比(標準偏差/平均値)が0.3以下である、非水電解質電池用セパレータ。 - 前記多孔質基材の厚みの平均値(μm)に対する多孔質基材の厚みの標準偏差の比(標準偏差/平均値)が、0.02以下である請求項1に記載の非水電解質電池用セパレータ。
- 前記接着性樹脂は、ポリフッ化ビニリデン系樹脂である請求項1又は請求項2に記載の非水電解質電池用セパレータ。
- 前記ポリフッ化ビニリデン系樹脂の重量平均分子量は、60万以上300万以下である、請求項3に記載の非水電解質電池用セパレータ。
- 前記多孔質基材のMD方向あるいはTD方向の伸度が50%以上200%以下である、請求項1~請求項4のいずれか1項に記載の非水電解質電池用セパレータ。
- 前記多孔質基材の突刺強度が200g以上800g以下である、請求項1~請求項5のいずれか1項に記載の非水電解質電池用セパレータ。
- 前記接着性多孔質層にはフィラーが含まれており、前記フィラーの前記接着性樹脂に対する質量比(フィラーの質量/接着性樹脂の質量)が0.01以上0.05以下である、請求項1~請求項6のいずれか1項に記載の非水電解質電池用セパレータ。
- 正極と、負極と、前記正極及び前記負極の間に配置された請求項1~請求項7のいずれか1項に記載の非水電解質電池用セパレータとを備え、リチウムのドープ・脱ドープにより起電力を得る非水電解質電池。
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR20157001087A KR20150032295A (ko) | 2012-07-30 | 2013-07-30 | 비수 전해질 전지용 세퍼레이터 및 비수 전해질 전지 |
CN201380040432.9A CN104508864B (zh) | 2012-07-30 | 2013-07-30 | 非水电解质电池用隔膜及非水电解质电池 |
JP2014510334A JP5643465B2 (ja) | 2012-07-30 | 2013-07-30 | 非水電解質電池用セパレータ及び非水電解質電池 |
US14/413,521 US9905825B2 (en) | 2012-07-30 | 2013-07-30 | Separator for nonaqueous electrolyte battery, and nonaqueous electrolyte battery |
KR1020167020461A KR102137131B1 (ko) | 2012-07-30 | 2013-07-30 | 비수 전해질 전지용 세퍼레이터 및 비수 전해질 전지 |
US15/866,590 US10622611B2 (en) | 2012-07-30 | 2018-01-10 | Separator for nonaqueous electrolyte battery, and nonaqueous electrolyte battery |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2012168989 | 2012-07-30 | ||
JP2012-168989 | 2012-07-30 |
Related Child Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/413,521 A-371-Of-International US9905825B2 (en) | 2012-07-30 | 2013-07-30 | Separator for nonaqueous electrolyte battery, and nonaqueous electrolyte battery |
US15/866,590 Continuation US10622611B2 (en) | 2012-07-30 | 2018-01-10 | Separator for nonaqueous electrolyte battery, and nonaqueous electrolyte battery |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2014021290A1 true WO2014021290A1 (ja) | 2014-02-06 |
Family
ID=50027964
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2013/070538 WO2014021290A1 (ja) | 2012-07-30 | 2013-07-30 | 非水電解質電池用セパレータ及び非水電解質電池 |
Country Status (5)
Country | Link |
---|---|
US (2) | US9905825B2 (ja) |
JP (1) | JP5643465B2 (ja) |
KR (2) | KR20150032295A (ja) |
CN (1) | CN104508864B (ja) |
WO (1) | WO2014021290A1 (ja) |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR20170027715A (ko) | 2014-06-30 | 2017-03-10 | 데이진 가부시키가이샤 | 비수계 이차전지용 세퍼레이터 및 비수계 이차전지 |
US9711775B2 (en) | 2014-08-29 | 2017-07-18 | Sumitomo Chemical Company, Limited | Laminated body, separator, and nonaqueous secondary battery |
JP2017226119A (ja) * | 2016-06-21 | 2017-12-28 | 住友化学株式会社 | 積層体 |
JP2017226120A (ja) * | 2016-06-21 | 2017-12-28 | 住友化学株式会社 | 積層体 |
WO2018221503A1 (ja) * | 2017-05-30 | 2018-12-06 | 東レ株式会社 | セパレータ |
WO2019107521A1 (ja) | 2017-11-30 | 2019-06-06 | 帝人株式会社 | 非水系二次電池用セパレータ及び非水系二次電池 |
US10811654B2 (en) | 2015-11-11 | 2020-10-20 | Teijin Limited | Separator for non-aqueous secondary battery and non-aqueous secondary battery |
JPWO2020189795A1 (ja) * | 2019-03-20 | 2021-04-08 | 帝人株式会社 | 非水系二次電池用セパレータ及び非水系二次電池 |
US11777175B2 (en) | 2015-07-02 | 2023-10-03 | Teijin Limited | Separator for non-aqueous secondary battery, non-aqueous secondary battery, and method of manufacturing non-aqueous secondary battery |
Families Citing this family (33)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8070708B2 (en) | 2004-02-03 | 2011-12-06 | V-Wave Limited | Device and method for controlling in-vivo pressure |
US9681948B2 (en) | 2006-01-23 | 2017-06-20 | V-Wave Ltd. | Heart anchor device |
US20210161637A1 (en) | 2009-05-04 | 2021-06-03 | V-Wave Ltd. | Shunt for redistributing atrial blood volume |
WO2010128501A1 (en) | 2009-05-04 | 2010-11-11 | V-Wave Ltd. | Device and method for regulating pressure in a heart chamber |
US11135054B2 (en) | 2011-07-28 | 2021-10-05 | V-Wave Ltd. | Interatrial shunts having biodegradable material, and methods of making and using same |
CN105555204B (zh) | 2013-05-21 | 2018-07-10 | V-波有限责任公司 | 用于递送减小左房压力的装置的设备 |
WO2016178171A1 (en) | 2015-05-07 | 2016-11-10 | The Medical Research Infrastructure And Health Services Fund Of The Tel-Aviv Medical Center | Temporary interatrial shunts |
US10835394B2 (en) | 2016-05-31 | 2020-11-17 | V-Wave, Ltd. | Systems and methods for making encapsulated hourglass shaped stents |
US20170340460A1 (en) | 2016-05-31 | 2017-11-30 | V-Wave Ltd. | Systems and methods for making encapsulated hourglass shaped stents |
JP7074419B2 (ja) | 2016-06-21 | 2022-05-24 | 住友化学株式会社 | 積層体 |
JP6647973B2 (ja) * | 2016-06-21 | 2020-02-14 | 住友化学株式会社 | 積層体 |
JP6754628B2 (ja) * | 2016-06-21 | 2020-09-16 | 住友化学株式会社 | 積層体 |
JP6736375B2 (ja) * | 2016-06-21 | 2020-08-05 | 住友化学株式会社 | 積層体 |
AU2018228451B2 (en) | 2017-03-03 | 2022-12-08 | V-Wave Ltd. | Shunt for redistributing atrial blood volume |
US11094997B2 (en) | 2017-05-29 | 2021-08-17 | Sumitomo Chemical Company, Limited | Nonaqueous electrolyte secondary battery |
JP6430621B1 (ja) | 2017-12-19 | 2018-11-28 | 住友化学株式会社 | 非水電解液二次電池 |
US11158907B2 (en) | 2017-12-19 | 2021-10-26 | Sumitomo Chemical Company, Limited | Nonaqueous electrolyte secondary battery |
US11205799B2 (en) | 2017-12-19 | 2021-12-21 | Sumitomo Chemical Company, Limited | Nonaqueous electrolyte secondary battery |
JP6430618B1 (ja) | 2017-12-19 | 2018-11-28 | 住友化学株式会社 | 非水電解液二次電池 |
JP6430623B1 (ja) | 2017-12-19 | 2018-11-28 | 住友化学株式会社 | 非水電解液二次電池 |
JP6430617B1 (ja) | 2017-12-19 | 2018-11-28 | 住友化学株式会社 | 非水電解液二次電池 |
US11744589B2 (en) | 2018-01-20 | 2023-09-05 | V-Wave Ltd. | Devices and methods for providing passage between heart chambers |
US10898698B1 (en) | 2020-05-04 | 2021-01-26 | V-Wave Ltd. | Devices with dimensions that can be reduced and increased in vivo, and methods of making and using the same |
US11458287B2 (en) | 2018-01-20 | 2022-10-04 | V-Wave Ltd. | Devices with dimensions that can be reduced and increased in vivo, and methods of making and using the same |
CN114335889B (zh) * | 2018-04-11 | 2024-04-05 | 宁德新能源科技有限公司 | 隔离膜及储能装置 |
US11495866B2 (en) | 2018-07-26 | 2022-11-08 | Lg Energy Solution, Ltd. | Separator and electrochemical device comprising same |
US11612385B2 (en) | 2019-04-03 | 2023-03-28 | V-Wave Ltd. | Systems and methods for delivering implantable devices across an atrial septum |
EP3972499A1 (en) | 2019-05-20 | 2022-03-30 | V-Wave Ltd. | Systems and methods for creating an interatrial shunt |
CN112259901B (zh) * | 2019-07-03 | 2022-03-18 | 比亚迪股份有限公司 | 锂离子电池用涂胶隔膜及其制备方法和应用 |
US11234702B1 (en) | 2020-11-13 | 2022-02-01 | V-Wave Ltd. | Interatrial shunt having physiologic sensor |
KR102582948B1 (ko) * | 2021-05-27 | 2023-09-27 | 더블유스코프코리아 주식회사 | 분리막 및 이를 포함하는 전기화학소자 |
CN116134673A (zh) * | 2022-03-31 | 2023-05-16 | 宁德新能源科技有限公司 | 一种隔膜、包含该隔膜的电化学装置及电子装置 |
AU2023252664A1 (en) | 2022-04-14 | 2024-10-17 | V-Wave Ltd. | Interatrial shunt with expanded neck region |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH10172606A (ja) * | 1996-12-04 | 1998-06-26 | Mitsubishi Electric Corp | リチウムイオン二次電池及びその製造方法 |
JP2001118558A (ja) * | 1999-10-19 | 2001-04-27 | Asahi Kasei Corp | 部分被覆されたセパレータ |
JP2004111160A (ja) * | 2002-09-17 | 2004-04-08 | Tomoegawa Paper Co Ltd | リチウムイオン二次電池用セパレーターおよびそれを用いたリチウムイオン二次電池 |
JP2006120462A (ja) * | 2004-10-21 | 2006-05-11 | Sanyo Electric Co Ltd | 非水電解質電池 |
JP2012043762A (ja) * | 2010-07-21 | 2012-03-01 | Toray Ind Inc | 複合多孔質膜、複合多孔質膜の製造方法並びにそれを用いた電池用セパレーター |
JP2012129116A (ja) * | 2010-12-16 | 2012-07-05 | Teijin Ltd | 非水電解質電池用セパレータ及び非水電解質電池 |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4127989B2 (ja) | 2001-09-12 | 2008-07-30 | 帝人株式会社 | 非水系二次電池用セパレータ及び非水系二次電池 |
CN101005129A (zh) * | 2002-08-22 | 2007-07-25 | 帝人株式会社 | 非水系二次电池及该电池中使用的隔板 |
KR100573358B1 (ko) * | 2002-09-17 | 2006-04-24 | 가부시키가이샤 도모에가와 세이시쇼 | 리튬이온2차전지용 세퍼레이터 및 이를 포함한리튬이온2차전지 |
JP5202948B2 (ja) * | 2005-06-24 | 2013-06-05 | 東レバッテリーセパレータフィルム株式会社 | ポリオレフィン微多孔膜の製造方法 |
KR101156248B1 (ko) * | 2006-10-30 | 2012-06-13 | 아사히 가세이 케미칼즈 가부시키가이샤 | 폴리올레핀제 미다공막 |
ATE538167T1 (de) * | 2007-01-30 | 2012-01-15 | Asahi Kasei E Materials Corp | Mikroporöse polyolefinmembran |
JPWO2009136648A1 (ja) * | 2008-05-09 | 2011-09-08 | 旭化成イーマテリアルズ株式会社 | 高出力密度リチウムイオン二次電池用セパレータ |
CN103280547B (zh) * | 2008-12-19 | 2015-09-23 | 旭化成电子材料株式会社 | 聚烯烃制微多孔膜及锂离子二次电池用分隔件 |
JP5511214B2 (ja) * | 2009-04-03 | 2014-06-04 | 旭化成イーマテリアルズ株式会社 | 多層多孔膜 |
CN103069612B (zh) * | 2010-08-09 | 2015-05-06 | 日本瑞翁株式会社 | 二次电池用多孔膜、制造方法及用途 |
-
2013
- 2013-07-30 US US14/413,521 patent/US9905825B2/en active Active
- 2013-07-30 WO PCT/JP2013/070538 patent/WO2014021290A1/ja active Application Filing
- 2013-07-30 KR KR20157001087A patent/KR20150032295A/ko active Application Filing
- 2013-07-30 JP JP2014510334A patent/JP5643465B2/ja active Active
- 2013-07-30 CN CN201380040432.9A patent/CN104508864B/zh active Active
- 2013-07-30 KR KR1020167020461A patent/KR102137131B1/ko active IP Right Grant
-
2018
- 2018-01-10 US US15/866,590 patent/US10622611B2/en active Active
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH10172606A (ja) * | 1996-12-04 | 1998-06-26 | Mitsubishi Electric Corp | リチウムイオン二次電池及びその製造方法 |
JP2001118558A (ja) * | 1999-10-19 | 2001-04-27 | Asahi Kasei Corp | 部分被覆されたセパレータ |
JP2004111160A (ja) * | 2002-09-17 | 2004-04-08 | Tomoegawa Paper Co Ltd | リチウムイオン二次電池用セパレーターおよびそれを用いたリチウムイオン二次電池 |
JP2006120462A (ja) * | 2004-10-21 | 2006-05-11 | Sanyo Electric Co Ltd | 非水電解質電池 |
JP2012043762A (ja) * | 2010-07-21 | 2012-03-01 | Toray Ind Inc | 複合多孔質膜、複合多孔質膜の製造方法並びにそれを用いた電池用セパレーター |
JP2012129116A (ja) * | 2010-12-16 | 2012-07-05 | Teijin Ltd | 非水電解質電池用セパレータ及び非水電解質電池 |
Cited By (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10714723B2 (en) | 2014-06-30 | 2020-07-14 | Teijin Limited | Separator for a non-aqueous secondary battery, and non-aqueous secondary battery |
KR20170027715A (ko) | 2014-06-30 | 2017-03-10 | 데이진 가부시키가이샤 | 비수계 이차전지용 세퍼레이터 및 비수계 이차전지 |
US9711775B2 (en) | 2014-08-29 | 2017-07-18 | Sumitomo Chemical Company, Limited | Laminated body, separator, and nonaqueous secondary battery |
US9711776B2 (en) | 2014-08-29 | 2017-07-18 | Sumitomo Chemical Company, Limited | Laminated body, separator, and nonaqueous secondary battery |
US9865857B2 (en) | 2014-08-29 | 2018-01-09 | Sumitomo Chemical Company, Limited | Laminated body, separator, and nonaqueous secondary battery |
US10014506B2 (en) | 2014-08-29 | 2018-07-03 | Sumitomo Chemical Company, Limited | Laminated body, separator, and nonaqueous secondary battery |
US11777175B2 (en) | 2015-07-02 | 2023-10-03 | Teijin Limited | Separator for non-aqueous secondary battery, non-aqueous secondary battery, and method of manufacturing non-aqueous secondary battery |
US10811654B2 (en) | 2015-11-11 | 2020-10-20 | Teijin Limited | Separator for non-aqueous secondary battery and non-aqueous secondary battery |
JP2017226119A (ja) * | 2016-06-21 | 2017-12-28 | 住友化学株式会社 | 積層体 |
JP2017226120A (ja) * | 2016-06-21 | 2017-12-28 | 住友化学株式会社 | 積層体 |
JPWO2018221503A1 (ja) * | 2017-05-30 | 2020-04-02 | 東レ株式会社 | セパレータ |
WO2018221503A1 (ja) * | 2017-05-30 | 2018-12-06 | 東レ株式会社 | セパレータ |
JP7070565B2 (ja) | 2017-05-30 | 2022-05-18 | 東レ株式会社 | セパレータの製造方法 |
WO2019107521A1 (ja) | 2017-11-30 | 2019-06-06 | 帝人株式会社 | 非水系二次電池用セパレータ及び非水系二次電池 |
JPWO2020189795A1 (ja) * | 2019-03-20 | 2021-04-08 | 帝人株式会社 | 非水系二次電池用セパレータ及び非水系二次電池 |
Also Published As
Publication number | Publication date |
---|---|
US20150180002A1 (en) | 2015-06-25 |
US10622611B2 (en) | 2020-04-14 |
KR20160093096A (ko) | 2016-08-05 |
CN104508864A (zh) | 2015-04-08 |
US9905825B2 (en) | 2018-02-27 |
KR20150032295A (ko) | 2015-03-25 |
US20180130988A1 (en) | 2018-05-10 |
JP5643465B2 (ja) | 2014-12-17 |
JPWO2014021290A1 (ja) | 2016-07-21 |
KR102137131B1 (ko) | 2020-07-24 |
CN104508864B (zh) | 2017-04-19 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5643465B2 (ja) | 非水電解質電池用セパレータ及び非水電解質電池 | |
JP5624251B2 (ja) | 非水電解質電池用セパレータ及び非水電解質電池 | |
US10096811B2 (en) | Separator for a non-aqueous secondary battery and non-aqueous secondary battery | |
US9431641B2 (en) | Separator for nonaqueous secondary battery, and nonaqueous secondary battery | |
JP5670811B2 (ja) | 非水系二次電池用セパレータおよび非水系二次電池 | |
JP5964951B2 (ja) | 非水電解質電池用セパレータおよび非水電解質電池 | |
JP5603522B2 (ja) | 非水電解質電池用セパレータおよび非水電解質電池 | |
KR20170095904A (ko) | 비수 전해질 전지용 세퍼레이터, 비수 전해질 전지, 및, 비수 전해질 전지의 제조 방법 | |
JP5584371B2 (ja) | 非水電解質電池用セパレータ、非水電解質電池、および、非水電解質電池の製造方法 | |
JP5612797B1 (ja) | 非水系二次電池用セパレータおよび非水系二次電池 | |
WO2013058368A1 (ja) | 非水系二次電池用セパレータ及び非水系二次電池 | |
TW201336154A (zh) | 非水系蓄電池用分隔器及非水系蓄電池 | |
WO2013058369A1 (ja) | 非水系二次電池用セパレータ及び非水系二次電池 | |
WO2014136837A1 (ja) | 非水系二次電池用セパレータおよび非水系二次電池 | |
JP2014026946A (ja) | 非水電解質電池用セパレータ及び非水電解質電池 | |
JP2014026947A (ja) | 非水電解質電池用セパレータ及び非水電解質電池 | |
JP6762089B2 (ja) | 非水電解液二次電池用積層セパレータ、非水電解液二次電池用部材および非水電解液二次電池 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
ENP | Entry into the national phase |
Ref document number: 2014510334 Country of ref document: JP Kind code of ref document: A |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 13825426 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 14413521 Country of ref document: US |
|
ENP | Entry into the national phase |
Ref document number: 20157001087 Country of ref document: KR Kind code of ref document: A |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 13825426 Country of ref document: EP Kind code of ref document: A1 |