Sodium molten salt battery

Patent metadata

Field	Value
Publication number	US-9711827-B2
Application number	US-201414891626-A
Country	US
Kind code	B2
Filing date	Mar 7, 2014
Priority date	May 17, 2013
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

Provided is a sodium molten-salt battery having good charge-discharge cycle characteristics. The sodium molten-salt battery includes a positive electrode that contains a positive electrode active material, a negative electrode that contains a negative electrode active material, and a molten-salt electrolyte that contains a sodium salt and an ionic liquid that dissolves the sodium salt. The negative electrode active material contains non-graphitizable carbon. The ionic liquid is a salt of a bis(sulfonyl)imide anion and a first onium cation that does not cause a Faradaic reaction with the non-graphitizable carbon. The molten-salt electrolyte contains a second onium cation in an amount of 1,000 ppm by mass or less. The second onium cation is represented by a general formula (1): R 1 R 2 R 3 R 4 N + where R 1 to R 4 are each independently a hydrogen atom or a methyl group.

First claim

The invention claimed is:

1. A sodium molten-salt battery comprising:
a positive electrode that contains a positive electrode active material;
a negative electrode that contains a negative electrode active material; and
a molten-salt electrolyte that contains a sodium salt and an ionic liquid that dissolves the sodium salt,
wherein the negative electrode active material contains non-graphitizable carbon,
the ionic liquid is a salt of a bis(sulfonyl)imide anion and a first onium cation that does not cause a Faradaic reaction with the non-graphitizable carbon,
the molten-salt electrolyte contains a second onium cation in an amount of 50 to 500 ppm by mass, and the second onium cation is represented by a general formula (1): R 1 R 2 R 3 R 4 N +
where R 1 to R 4 are each independently a hydrogen atom or a methyl group.

2. The sodium molten-salt battery according to claim 1 , wherein the first onium cation is an organic onium cation having a nitrogen-containing heterocycle.

3. The sodium molten-salt battery according to claim 2 , wherein the nitrogen-containing heterocycle has a pyrrolidine skeleton.

4. The sodium molten-salt battery according to claim 1 , wherein the sodium salt is a salt of a sodium ion and a bis(sulfonyl)imide anion.

Assignees

• Sumitomo Electric Industries

Inventors

• Fukunaga Atsushi
• Inazawa Shinji
• Nitta Koji
• Sakai Shoichiro
• Imazaki Eiko
• Numata Koma

Classifications

• H01M2300/0048

  Molten electrolytes used at high temperature · CPC title

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M2220/10

  Batteries in stationary systems, e.g. emergency power source in plant · CPC title

• H01M10/054

  Accumulators with insertion or intercalation of metals other than lithium, e.g. with magnesium or aluminium · CPC title

• H01M2300/0045

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