Nonaqueous electrolyte and nonaqueous secondary battery

Patent metadata

Field	Value
Publication number	US-10756394-B2
Application number	US-201615558272-A
Country	US
Kind code	B2
Filing date	Mar 30, 2016
Priority date	Mar 31, 2015
Publication date	Aug 25, 2020
Grant date	Aug 25, 2020

Abstract

The purpose of the present invention is to provide a nonaqueous electrolyte that contains acetonitrile having an excellent balance between viscosity and the dielectric constant and a fluorine-containing inorganic lithium salt, wherein the generation of complex cations comprising a transition metal and acetonitrile is suppressed, excellent load characteristics are exhibited, and increases in internal resistance upon repeated charge/discharge cycles are suppressed; a further purpose of the present invention is to provide a nonaqueous secondary battery. The present invention relates to a nonaqueous electrolyte which contains: a nonaqueous solvent comprising acetonitrile; a fluorine-containing inorganic lithium salt; and a specific nitrogenous cyclic compound typified by benzotriazole.

First claim

The invention claimed is:

1. A non-aqueous electrolyte solution comprising:
a non-aqueous solvent containing acetonitrile,
LiPF 6 , and
a compound represented by the following general formula (1):

wherein A is a nitrogen atom,
R 1 is an alkyl group having 1 to 4 carbon atoms, bis(N,N′-alkyl)aminomethyl group, or bis(N,N′-alkyl)aminoethyl group,
R 2 is an alkyl group having 1 to 4 carbon atoms, a fluorine-substituted alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a fluorine-substituted alkoxy group having 1 to 4 carbon atoms, nitrile group, nitro group, amino group, or a halogen atom, and k is an integer of 0 to 4.

2. The non-aqueous electrolyte solution according to claim 1 , wherein the non-aqueous solvent contains acetonitrile in 20 to 100% by volume.

3. The non-aqueous electrolyte solution according to claim 1 , wherein content of the compound represented by general formula (1) above is 0.01 to 10 parts by mass, relative to 100 parts by mass of the non-aqueous electrolyte solution.

4. A non-aqueous secondary battery comprising:
a positive electrode having a positive electrode active material layer containing at least one transition metal element selected from Ni, Mn, and Co, on one surface or both surfaces of a current collector;
a negative electrode having a negative electrode active material layer on one surface or both surfaces of another current collector; and
the non-aqueous electrolyte solution according to claim 1 .

5. The non-aqueous secondary battery according to claim 4 , wherein the positive electrode active material layer and the negative electrode active material layer face each other, and
ratio of the entire area of the surface of the side of the negative electrode active material layer opposing to the positive electrode active material layer, relative to the area of the region where the positive electrode active material layer and the negative electrode active material layer face each other, is larger than 1.0 and below 1.1.

6. The non-aqueous electrolyte solution according to claim 2 , wherein content of the compound represented by general formula (1) above is 0.01 to 10 parts by mass, relative to 100 parts by mass of the non-aqueous electrolyte solution.

7. A non-aqueous secondary battery comprising:
a positive electrode having a positive electrode active material layer containing at least one transition metal element selected from Ni, Mn, and Co, on one surface or both surfaces of a current collector;
a negative electrode having a negative electrode active material layer on one surface or both surfaces of another current collector; and
the non-aqueous electrolyte solution according to claim 2 .

8. A non-aqueous secondary battery comprising:
a positive electrode having a positive electrode active material layer containing at least one transition metal element selected from Ni, Mn, and Co, on one surface or both surfaces of a current collector;
a negative electrode having a negative electrode active material layer on one surface or both surfaces of another current collector; and
the non-aqueous electrolyte solution according to claim 3 .

Assignees

• Asahi Chemical Ind

Inventors

• Matsuoka Naoki
• Yoshino Akira
• Natsume Yutaka
• Kishimi Mitsuhiro
• Kamine Hirokazu

Classifications

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M10/0567

  characterised by the additives · CPC title

• H01M10/058

  Construction or manufacture · CPC title

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title