Nonaqueous electrolyte solution and secondary battery

Patent metadata

Field	Value
Publication number	US-10978737-B2
Application number	US-201515321649-A
Country	US
Kind code	B2
Filing date	Jun 23, 2015
Priority date	Jun 23, 2014
Publication date	Apr 13, 2021
Grant date	Apr 13, 2021

Abstract

The present invention relates to an electrolyte solution comprising a supporting salt, a nonaqueous solvent containing a compound having a viscosity of 1.0 mPa-s or less in an amount of more than 50% by volume in the nonaqueous solvent, and a halogenated cyclic acid anhydride. According to the present invention, an electrolyte solution capable of suppressing gas generation is provided.

First claim

The invention claimed is:

1. A secondary battery comprising an electrode element comprising a positive electrode comprising a positive electrode active material and a negative electrode comprising a negative electrode active material, and an electrolyte solution, wherein the electrolyte solution comprises:
a supporting salt selected from lithium salts,
a non-aqueous solvent consisting of (i) a compound having a viscosity of 1.0 mPa-s or less selected from open-chain carbonates in an amount of 60% by volume or more in the non-aqueous solvent and (ii) at least one solvent selected from the group consisting of a cyclic carbonate, γ-lactones, cyclic ethers, and their fluorine derivatives, wherein the selected cyclic carbonate is one of ethylene carbonate, butylene carbonate and vinylene carbonate, and
a halogenated cyclic carboxylic acid anhydride in which all hydrogen atoms are substituted with fluorine atoms, in a content of 0.1 mass % or more to 5 mass % or less in the electrolyte solution;
further wherein the negative electrode active material comprises graphite and the positive electrode active material comprises a lithium composite oxide Li α Ni β Co γ Mn δ O 2 (1≤α≤1.2, β+γ+δ=1, 1>β≥0.5, γ≤0.4, and 0<δ) in which a part of the transition metals thereof may be replaced by at least one element selected from the group consisting of Al, Mg, and Zr; and
wherein the secondary battery uses a laminate film as a package.

2. The secondary battery according to claim 1 , wherein the negative electrode active material comprises an artificial graphite.

3. A vehicle equipped with the secondary battery according to claim 1 .

4. The secondary battery according to claim 1 , wherein the halogenated cyclic acid anhydride is a compound in which carbon skeleton is constituted by single bonds only.

5. The secondary battery according to claim 1 , wherein the compound having a viscosity of 1.0 mPa-s or less is at least a compound selected from the group consisting of dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate.

6. The secondary battery according to claim 1 , wherein the negative electrode further comprises at least one of silicon and silicon oxide.

7. The secondary battery according to claim 1 , wherein the negative electrode active material is graphite.

8. The secondary battery according to claim 1 , wherein the halogenated cyclic acid anhydride is one or more compounds selected from the group consisting of the following compounds:

9. The secondary battery according to claim 1 , wherein the non-aqueous solvent comprises diethyl carbonate, as the compound having a viscosity of 1.0 mPa-s or less, in an amount of 60% by volume or more in the non-aqueous solvent.

10. The secondary battery according to claim 1 , wherein the amount of the compound having a viscosity of 1.0 mPa-s or less selected from open-chain carbonates is 70% by volume or more in the non-aqueous solvent.

Assignees

• Nec Corp

Inventors

• Yoshida Noboru
• Shimanuki Ikiko
• Saitho Shinsaku
• Ishikawa Hitoshi

Classifications

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M10/4235

  Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence) · CPC title

• H01M10/0569

  characterised by the solvents · CPC title

• H01M2300/0028

  characterised by the solvent · CPC title

• H01M10/0567 Primary

  characterised by the additives · CPC title