# US 10,312,491 B2 · Separator and battery

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- Number: US 10,312,491 B2
- Document ID: US10312491B2
- Status: Granted
- Kind: B2
- Application number: 12/959,638
- Filed: 2010-12-03
- Published: 2011-12-01
- Granted: 2019-06-04
- Earliest claimed: 2009-12-04
- Assignees: Murata Manufacturing Co., Ltd.
- Applicants: Kazuki Chiba; Atsushi Kajita; Yukako Teshima; Masatake Hayashi
- Inventors: Kazuki Chiba; Atsushi Kajita; Yukako Teshima; Masatake Hayashi
- Web page: https://patentgrep.com/patent/US10312491B2

## CPC

- H01M 10/0431: {Cells with wound or folded electrodes (H01M10/045 takes precedence)}
- B32B 1/08: Tubular products
- B32B 15/085: comprising polyolefins
- H01M 50/417: Polyolefins
- H01M 50/426: Fluorocarbon polymers
- H01M 50/446: Composite material consisting of a mixture of organic and inorganic materials
- H01M 50/451: comprising layers of only organic material and layers containing inorganic material
- H01M 50/463: Separators, membranes or diaphragms characterised by their shape
- H01M 50/489: Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
- H01M 50/491: Porosity
- B32B 2250/40: Symmetrical or sandwich layers, e.g. ABA, ABCBA, ABCCBA
- B32B 2255/10: on synthetic resin layer or on natural or synthetic rubber layer
- B32B 2255/26: Polymeric coating
- B32B 2307/50: having particular mechanical properties
- B32B 2307/724: Permeability to gases, adsorption
- B32B 2457/10: Batteries
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- H01M 50/403: Manufacturing processes of separators, membranes or diaphragms
- Y02E 60/10: Energy storage using batteries
- Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

A separator includes a first layer that has a first principal face and a second principal face, and a second layer that is formed on at least one of the first principal face and the second principal face. The first layer is a microporous membrane including a first polymer resin, and the second layer is a microporous membrane including inorganic particles having an electrically insulating property and a second polymer resin.

## Claims

### Claim 1

A separator comprising:
a first resin layer having a first principal face and a second principal face; and
a second resin layer provided on at least one of the first principal face and the second principal face;
wherein the second resin layer includes inorganic particles, and a volume fraction of the inorganic particles in the second resin layer is equal to or greater than 60 vol % and equal to or lower than 90 vol %,
wherein an average particle diameter D20 of the inorganic particles is larger than an average pore diameter of pores opening onto a surface of the first resin layer, and the average pore diameter of the pores ranges from 0.03 μm to 0.10 μm,
wherein an average particle diameter D20 of the inorganic particles of the second resin layer ranges from 0.13 μm to 0.21 μm,
wherein the average particle diameter D90 of the inorganic particles of the second resin layer ranges from 2.00 μm to 5.00 μm and is greater than the average particle diameter D20,
wherein the second resin layer includes one or more of materials selected from the group consisting of polyvinylidene fluoride, polyhexafluoropropylene, polysiloxane, polyacrylic acid, polymethacrylate and nitrile butadiene rubber,
wherein a difference between air permeability of the separator and air permeability of the first layer is equal to or less than 60 sec/100 ml, and
wherein the second resin layer comprises fibrils having the average diameter of equal to or less than 1 μm.

### Claim 2 (depends on 1)

The separator according to claim 1, wherein an air-permeability rising rate of air permeability at a time when pressure is applied to the separator for two minutes at 60° C. under 50 kgf/cm2 with respect to air permeability before the pressure load is equal to or lower than 35%.

### Claim 3 (depends on 1)

The separator according to claim 1, wherein an average membrane thickness of the first layer is equal to or greater than 10.0 μm and less than 30.0 μm.

### Claim 4 (depends on 1)

The separator according to claim 1, wherein an average particle diameter D90 of the inorganic particles is equal to or less than ⅓ of the membrane thickness of the first layer.

### Claim 5 (depends on 1)

The separator according to claim 1, wherein an area density per a unit area of the second resin layer is equal to or greater than 0.2 mg/cm2 and equal to or less than 1.8 mg/cm2.

### Claim 6

A battery comprising:
a positive electrode;
a negative electrode;
an electrolyte; and
a separator,
wherein the separator includes
a first resin layer having a first principal face and a second principal face and
a second resin layer provided on at least one of the first principal face and the second principal face;
wherein the second resin layer includes inorganic particles, and a volume fraction of the inorganic particles in the second resin layer is equal to or greater than 60 vol % and equal to or lower than 90 vol %,
wherein an average particle diameter D20 of the inorganic particles is larger than an average pore diameter of pores opening onto a surface of the first resin layer, and the average pore diameter of the pores ranges from 0.03 μm to 0.10 μm,
wherein an average particle diameter D20 of the inorganic particles of the second resin layer ranges from 0.13 μm to 0.21 μm,
wherein the average particle diameter D90 of the inorganic particles of the second resin layer ranges from 2.00 μm to 5.00 μm and is greater than the average particle diameter D20,
wherein the second resin layer includes one or more of materials selected from the group consisting of polyvinylidene fluoride, polyhexafluoropropylene, polysiloxane, polyacrylic acid, polymethacrylate and nitrile butadiene rubber,
wherein a difference between air permeability of the separator and air permeability of the first layer is equal to or less than 60 sec/100 ml, and
wherein the second resin layer comprises fibrils having the average diameter of equal to or less than 1 μm.

### Claim 7 (depends on 6)

The battery according to claim 6, wherein an open-circuit voltage in a fully-charged state is in the range of 4.2 V to 4.6 V.

### Claim 8 (depends on 6)

The battery according to claim 6, wherein an air-permeability rising rate of air permeability at a time when pressure is applied to the separator for two minutes at 60° C. under 50 kgf/cm2 with respect to air permeability before the pressure load to the separator is equal to or lower than 35%.

### Claim 9 (depends on 6)

The battery according to claim 6, wherein the positive electrode, the negative electrode and the separator are stacked and wound to constitute a wound electrode body,
an outer end of the separator is exposed on the periphery of the wound electrode body.

### Claim 10 (depends on 9)

The battery according to claim 9, wherein a lead is connected to at least one of outer ends of the positive electrode and the negative electrode.

### Claim 11 (depends on 10)

The battery of claim 10, wherein at least one of outer and inner principal faces of a collector of the positive electrode or the negative electrode is exposed at the at least one of the outer ends of the positive electrode and the negative electrode and the lead is connected to the exposed portion of the collector.

### Claim 12 (depends on 6)

The battery according to claim 6, wherein an area density per unit area of the second resin layer is equal to or greater than 0.2 mg/cm2 and equal to or less than 1.8 mg/cm2.

### Claim 13 (depends on 1)

The separator according to claim 1, wherein the first resin layer includes a first resin having chemical stability that is mixed or copolymerized with polyethylene or polypropylene.

### Claim 14 (depends on 1)

The separator according to claim 1, wherein the second polymer resin includes polyhexafluoropropylene.

### Claim 15 (depends on 1)

The separator according to claim 1, wherein the second resin layers are formed on both of the first principal face and the second principal face of the first resin layer.

### Claim 16 (depends on 1)

The separator according to claim 1, wherein the second resin layer has a fibrillated mesh-shaped structure with the inorganic particles being separately dispersed.

### Claim 17 (depends on 1)

The separator according to claim 1, wherein the second resin layer includes one or more of materials selected from the group consisting of polysiloxane, polyvinyl alcohol, polyacrylic acid, styrene-butadiene rubber and nitrile butadiene rubber.

### Claim 18 (depends on 1)

The separator according to claim 1, wherein the inorganic particles includes at least one of alumina, silica, zirconia and titania.

### Claim 19 (depends on 6)

The battery according to claim 6, wherein the second resin layer includes one or more of materials selected from the group consisting of polysiloxane, polyvinyl alcohol, polyacrylic acid, styrene-butadiene rubber and nitrile butadiene rubber.

### Claim 20 (depends on 6)

The battery according to claim 6, wherein the volume fraction of the inorganic particles in the second resin layer is 82 vol % or more.

### Claim 21 (depends on 6)

The battery according to claim 6, wherein the inorganic particles includes at least one of alumina, silica, zirconia and titania.

### Claim 22 (depends on 1)

An electronic apparatus comprising the battery according to claim 1.

### Claim 23 (depends on 1)

The separator according to claim 1, wherein the average pore diameter of the pores ranges from 0.03 μm to 0.05 μm.

### Claim 24 (depends on 6)

The battery according to claim 6, wherein the average pore diameter of the pores ranges from 0.03 μm to 0.05 μm.