Nonaqueous solvent, nonaqueous electrolyte, and power storage device

Patent metadata

Field	Value
Publication number	US-9577290-B2
Application number	US-201213719562-A
Country	US
Kind code	B2
Filing date	Dec 19, 2012
Priority date	Dec 23, 2011
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

A power storage device using an organic solvent as a nonaqueous solvent for a nonaqueous electrolyte, in which a CV charging period in CCCV charging can be prevented from being extended and which has high performance, can be provided. The power storage device includes a positive electrode, a negative electrode, and a nonaqueous electrolyte. The nonaqueous electrolyte includes an ionic liquid including an alicyclic quaternary ammonium cation having one or more substituents and a counter anion to the alicyclic quaternary ammonium cation, a cyclic ester, and an alkali metal salt. In particular, in the power storage device, the ionic liquid content is greater than or equal to 70 wt % and less than 100 wt % per unit weight of the ionic liquid and the cyclic ester in the nonaqueous electrolyte, or greater than or equal to 50 wt % and less than 80 wt % per unit weight of the nonaqueous electrolyte.

First claim

What is claimed is:

1. A liquid comprising:
a cyclic ester; and
an ionic liquid represented by General Formula (G1),

wherein one of R 1 to R 5 represents a methyl group; and
wherein the other of R 1 to R 5 each represent a hydrogen atom;
and
A 1 − represents any of a monovalent imide-based anion, a monovalent methide-based anion, a perfluoroalkyl sulfonic acid anion, tetrafluoroborate, and hexafluorophosphate.

2. The liquid according to claim 1 , wherein the liquid is a nonaqueous solvent.

3. The liquid according to claim 1 , wherein a content of the ionic liquid is greater than or equal to 70 wt % and less than 100 wt % per unit weight of the ionic liquid and the cyclic ester.

4. The liquid according to claim 1 , wherein the cyclic ester is ethylene carbonate or propylene carbonate.

5. A power storage device comprising:
a positive electrode;
a negative electrode; and
an electrolyte comprising:
a cyclic ester;
an alkali metal salt; and
an ionic liquid represented by General Formula (G1),

wherein one of R 1 to R 5 represents a methyl group; and
wherein the other of R 1 to R 5 each represent a hydrogen atom;
and
A 1 − represents any of a monovalent imide-based anion, a monovalent methide-based anion, a perfluoroalkyl sulfonic acid anion, tetrafluoroborate, and hexafluorophosphate.

6. The power storage device according to claim 5 , wherein a content of the ionic liquid is greater than or equal to 70 wt % and less than 100 wt % per unit weight of the ionic liquid and the cyclic ester in the electrolyte.

7. The power storage device according to claim 5 , wherein a content of the ionic liquid is greater than or equal to 50 wt % and less than 80 wt % per unit weight of the electrolyte.

8. The power storage device according to claim 5 , wherein the cyclic ester is ethylene carbonate or propylene carbonate.

9. The power storage device according to claim 5 , wherein the alkali metal salt in the electrolyte is a lithium salt.

10. The liquid according to claim 1 ,
wherein A 1 − represents any of (C n F 2n+1 SO 2 ) 2 N − , CF 2 (CF 2 SO 2 ) 2 N − and (C m F 2m+1 SO 3 ) − ,
wherein n is 0 to 3, and
wherein m is 0 to 4.

11. The liquid according to claim 1 ,
wherein R 2 represents a methyl group, and
wherein R 1 and R 3 to R 5 each represent hydrogen.

12. An electrolyte comprising:
the liquid according to claim 1 ; and
an alkali metal salt.

13. The electrolyte according to claim 12 , wherein the alkali metal salt in the electrolyte is a lithium salt.

14. The electrolyte according to claim 12 , wherein a content of the ionic liquid is greater than or equal to 50 wt % and less than 80 wt % per unit weight of the ionic liquid, the cyclic ester and the alkali metal salt.

15. A liquid comprising:
a cyclic ester; and
an ionic liquid represented by General Formula (G4)

wherein:
one of R 1 to R 4 represents a methyl group;
the other of R 1 to R 4 each represent a hydrogen atom;
R 5 and R 6 represent different alkyl groups having 1 to 4 carbon atoms; and
A 1 − represents any of a monovalent imide-based anion, a monovalent methide-based anion, a perfluoroalkyl sulfonic acid anion, tetrafluoroborate, and hexafluorophosphate.

16. The liquid according to claim 15 , wherein a content of the ionic liquid is greater than or equal to 70 wt % and less than 100 wt % per unit weight of the ionic liquid and the cyclic ester.

17. The liquid according to claim 15 , wherein the cyclic ester is ethylene carbonate.

18. The liquid according to claim 15 ,
wherein A 1 − represents any of (C n F 2n+1 SO 2 ) 2 N − , CF 2 (CF 2 SO 2 ) 2 N − and (C m F 2m+1 SO 3 ) − ,
wherein n is 0 to 3, and
wherein m is 0 to 4.

19. An electrolyte comprising:
the liquid according to claim 15 ; and
an alkali metal salt.

20. The electrolyte according to claim 19 , wherein the alkali metal salt in the electrolyte is a lithium salt.

21. The electrolyte according to claim 19 , wherein a content of the ionic liquid is greater than or equal to 50 wt % and less than 80 wt % per unit weight of the ionic liquid, the cyclic ester and the alkali metal salt.

22. A power storage device comprising:
a positive electrode;
a negative electrode; and
an electrolyte comprising:
the liquid according to claim 15 ; and
an alkali metal salt.

23. The power storage device according to claim 5 ,
wherein A 1 − represents any of (C n F 2n+1 SO 2 ) 2 N − , CF 2 (CF 2 SO 2 ) 2 N − and (C m F 2m+1 SO 3 ) − ,
wherein n is 0 to 3, and
wherein m is 0 to 4.

24. The power storage device according to claim 5 ,
wherein R 2 represents a methyl group,
wherein R 1 and R 3 to R 5 each represent hydrogen,
wherein R 6 represents a methyl group, and
wherein R 7 represents a propyl group.

Assignees

• Semiconductor Energy Lab

Inventors

• Ito Kyosuke
• Itakura Toru
• Inoue Nobuhiro
• Ishikawa Jun
• Momo Junpei

Classifications

• H01M10/052

  Li-accumulators · CPC title

• H01M10/0569 Primary

  characterised by the solvents · CPC title

• H01M2300/0045

  Room temperature molten salts comprising at least one organic ion · CPC title

• Y02E60/122

  Cross-Sectional Technologies · mapped topic

• Y02T10/7011

  Cross-Sectional Technologies · mapped topic