# US 10,374,255 B2 · Nonaqueous electrolyte secondary battery

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- Number: US 10,374,255 B2
- Document ID: US10374255B2
- Status: Granted
- Kind: B2
- Application number: 14/402,757
- Filed: 2013-04-30
- Published: 2015-05-28
- Granted: 2019-08-06
- Earliest claimed: 2012-05-22
- Assignees: Toyota Jidosha Kabushiki Kaisha
- Applicants: Toyota Jidosha Kabushiki Kaisha
- Inventors: Tomohiro Nakano; Satoshi Goto; Tomohide Sumi; Hideki Sano
- Web page: https://patentgrep.com/patent/US10374255B2

## CPC

- H01M 10/0567: characterised by the additives
- H01M 4/13: Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M 4/139: Processes of manufacture
- H01M 4/628: {Inhibitors, e.g. gassing inhibitors, corrosion inhibitors}
- H01M 10/052: Li-accumulators
- H01M 4/366: {as layered products}
- H01M 10/446: {Initial charging measures}
- Y02E 60/10: Energy storage using batteries
- Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product
- Y02T 10/70: Energy storage systems for electromobility, e.g. batteries
- Y10T 29/49115: including coating or impregnating
- 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
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

Provided is a nonaqueous electrolyte secondary battery in which the following are housed in a battery case: a nonaqueous electrolyte, a boron atom-containing oxalato complex compound, and an electrode assembly in which a positive electrode having a positive electrode active material and a negative electrode having a negative electrode active material are disposed facing each other. Here, a coat containing boron atoms originating from the oxalato complex compound is formed on the surface of the negative electrode active material, and the amount BM (μg/cm2) of the boron atom as measured based on inductively coupled plasma-atomic emission spectroscopic analysis and the intensity BA for a tricoordinate boron atom as measured based on x-ray absorption fine structure analysis satisfy 0.5≤BA/BM≤1.0.

## Claims

### Claim 1

A nonaqueous electrolyte secondary battery in which an electrode assembly in which a positive electrode having a positive electrode active material and a negative electrode having a negative electrode active material are disposed facing each other,
a nonaqueous electrolyte, and
a boron (B) atom-containing oxalato complex compound are housed in a battery case, wherein
a coat containing boron (B) atoms that originate from the oxalato complex compound is formed on the surface of the negative electrode active material, and
a ratio on the surface of the negative electrode active material between an amount BM (μg/cm2) of the boron atom, as measured based on inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and an intensity BA for a tricoordinate boron (B) atom, as measured based on x-ray absorption fine structure (XAFS) analysis, is 0.5≤BA/Bm≤1.0.

### Claim 2 (depends on 1)

The nonaqueous electrolyte secondary battery according to claim 1, wherein an amount of addition of the boron (B) atom-containing oxalato complex compound is at least 3 μmol/g and not more than 200 μmol/g with reference to the negative electrode active material.

### Claim 3 (depends on 1)

The nonaqueous electrolyte secondary battery according to claim 1, wherein the boron (B) atom-containing oxalato complex compound is lithium bis(oxalato)borate.

### Claim 4 (depends on 1)

The nonaqueous electrolyte secondary battery according to claim 1, wherein the negative electrode active material is a particulate and a specific surface area of this particulate negative electrode active material based on a BET method is at least 1 m2/g and not more than 10 m2/g.

### Claim 5 (depends on 1)

A battery pack comprising a combination of a plurality of nonaqueous electrolyte secondary batteries according to claim 1.

### Claim 6 (depends on 1)

The nonaqueous electrolyte secondary battery according to claim 1, wherein the coat containing boron (B) atoms that originate from the oxalato complex compound is formed on the surface of the negative electrode active material by carrying out a charging process such that a voltage between the positive electrode and the negative electrode reaches a prescribed value, wherein a charging rate in the charging process is set as at least 1.5 C and not more than 5 C.

### Claim 7 (depends on 6)

The nonaqueous electrolyte secondary battery according to claim 6, wherein the charging process includes:
a first charging process of charging for a prescribed amount of time at a prescribed charging rate set within the charging rate range; and
a second charging process of charging to a prescribed voltage at a charging rate that is higher than that in the first charging process.

### Claim 8 (depends on 7)

The nonaqueous electrolyte secondary battery according to claim 7, wherein the charging rate in the second charging process is set at a value that is at least 1.5-times and not more than 3-times the charging rate in the first charging process.