# US 12,224,452 B2 · Nonaqueous electrolyte secondary battery including separator with filler layers on opposite sides of substrate

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- Number: US 12,224,452 B2
- Document ID: US12224452B2
- Status: Granted
- Kind: B2
- Application number: 16/637,034
- Filed: 2018-11-02
- Published: 2020-07-30
- Granted: 2025-02-11
- Earliest claimed: 2017-11-29
- Assignees: Panasonic Intellectual Property Management Co., Ltd.
- Applicants: Panasonic Intellectual Property Management Co., Ltd.
- Inventors: Yuki Morikawa; Masanori Sugimori; Yasunori Baba; Katsunori Yanagida; Nobuhiro Hirano
- Web page: https://patentgrep.com/patent/US12224452B2

## CPC

- H01M 50/46: Separators, membranes or diaphragms characterised by their combination with electrodes
- H01M 4/131: Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
- H01M 4/366: {as layered products}
- H01M 4/58: of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
- H01M 4/668: {Composites of electroconductive material and synthetic resins}
- H01M 10/0431: {Cells with wound or folded electrodes (H01M10/045 takes precedence)}
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- H01M 10/058: Construction or manufacture
- H01M 50/417: Polyolefins
- H01M 50/423: Polyamide resins
- 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 50/457: comprising three or more layers
- H01M 50/461: {with adhesive layers between electrodes and separators}
- H01M 10/0587: of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
- H01M 50/44: Fibrous material
- H01M 2004/021: {Physical characteristics, e.g. porosity, surface area}
- H01M 2004/028: {Positive electrodes}
- 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
- 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

In a nonaqueous electrolyte secondary battery, a separator includes a substrate, a first filler layer disposed on one side of the substrate and containing phosphate salt particles, and a second filler layer disposed on the other side of the substrate and containing inorganic particles. The separator is disposed between a positive electrode and a negative electrode in such a manner that the side of the substrate which bears the first filler layer is directed to the positive electrode side.

## Claims

### Claim 1

A nonaqueous electrolyte secondary battery comprising a positive electrode, a negative electrode and a separator, wherein
the separator comprises a substrate, a first filler layer disposed on one side of the substrate and containing phosphate salt particles, and a second filler layer disposed on the other side of the substrate and containing inorganic particles with a higher melting point than the phosphate salt particles, the separator being disposed between the positive electrode and the negative electrode in such a manner that the first filler layer is directed to the positive electrode side, and
the BET specific surface area of the phosphate salt particles is not less than 5 m2/g and not more than 100 m2/g,
wherein the average particle size of the phosphate salt particles is 0.05 μm to 1 μm and is smaller than the average pore size of the substrate,
wherein the separator further comprises a resin layer containing a polyolefin, said resin layer being disposed on the surface of the first filler layer and in contact with the positive electrode,
wherein the first filler layer comprises a continuous layer configured to cover an entirety of a surface of the substrate on which the first filler layer is disposed,
wherein the phosphate salt particles contained in the first filler layer are configured to undergo melting and polycondensation by heat and a potential of the positive electrode, so as to fill pores in the substrate upon generation of a heat, and
wherein a porosity of the first filler layer is 30% or more and 70% or less.

### Claim 2 (depends on 1)

The nonaqueous electrolyte secondary battery according to claim 1, wherein the BET specific surface area of the phosphate salt particles is not less than 20 m2/g and not more than 100 m2/g.

### Claim 3 (depends on 1)

The nonaqueous electrolyte secondary battery according to claim 1, wherein the phosphate salt particles are at least one selected from lithium phosphate, dilithium hydrogen phosphate and lithium dihydrogen phosphate.