# US 2020/0403221 A1 · Nonaqueous electrolyte secondary battery

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- Number: US 2020/0403221 A1
- Document ID: US20200403221A1
- Status: Published application
- Kind: A1
- Application number: 16/975,829
- Filed: 2019-02-13
- Published: 2020-12-24
- Earliest claimed: 2018-02-28
- Assignees: Panasonic Intellectual Property Management Co., Ltd.
- Applicants: Panasonic Intellectual Property Management Co., Ltd.
- Inventors: Fumiharu Niina; Kouhei Tsuzuki; Katsunori Yanagida
- Web page: https://patentgrep.com/patent/US20200403221A1

## CPC

- H01M 4/134: Electrodes based on metals, Si or alloys
- H01M 4/131: Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
- H01M 4/133: Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
- H01M 4/364: {as mixtures}
- H01M 4/366: {as layered products}
- H01M 4/483: {for non-aqueous cells (H01M4/485 takes precedence)}
- H01M 4/525: of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
- H01M 4/587: for inserting or intercalating light metals
- H01M 4/622: {being polymers}
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- H01M 10/4235: {Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence)}
- H01M 2004/027: {Negative electrodes}
- 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 positive electrode active material contains a titanium lithium complex oxide that has a lattice shrinkage in charged state of 98.5% or less. A negative electrode mix layer contains a polyacrylic acid or a salt thereof and includes a first layer and a second layer disposed successively from a negative electrode collector. Each of the first layer and the second layer contains a carbon-based negative electrode active material, and the ratio (B/A) of the D-band/G-band ratio (B) of the Raman spectrum of the second layer to the D-band/G-band ratio (A) of the Raman spectrum of the first layer is 2 to 10. The concentration of the polyacrylic acid or a salt thereof in the first layer is higher than the concentration of the polyacrylic acid or a salt thereof in the second layer.

## Claims

### Claim 1

A nonaqueous electrolyte secondary battery comprising a positive electrode containing a positive electrode active material, a negative electrode including a negative electrode mix layer disposed on a negative electrode collector, and a nonaqueous electrolyte,
wherein the positive electrode active material contains a titanium lithium complex oxide that has a lattice shrinkage in charged state of 98.5% or less,
the negative electrode mix layer contains a polyacrylic acid or a salt thereof and includes a first layer and a second layer disposed successively from the negative electrode collector,
each of the first layer and the second layer contains a carbon-based negative electrode active material,
the ratio (B/A) of the D-band/G-band ratio (B) of the Raman spectrum of the second layer to the D-band/G-band ratio (A) of the Raman spectrum of the first layer is 2 to 10, and
the concentration of the polyacrylic acid or a salt thereof in the first layer is higher than the concentration of the polyacrylic acid or a salt thereof in the second layer.

### Claim 2 (depends on 1)

The nonaqueous electrolyte secondary battery according to claim 1, wherein the thickness of the second layer is 20% to 70% of the thickness of the negative electrode mix layer.

### Claim 3 (depends on 1)

The nonaqueous electrolyte secondary battery according to claim 1, wherein the second layer contains substantially no polyacrylic acid nor salt thereof.

### Claim 4 (depends on 1)

The nonaqueous electrolyte secondary battery according to claim 1, wherein the first layer contains a silicon compound.