Sodium molten-salt battery and molten-salt electrolyte or ionic liquid used therein

Abstract

Provided is a sodium molten-salt battery having good storage characteristics and 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 ionic liquid contains a salt of an anion and a pyrrolidinium cation having, at the 1-position, a methyl group and an alkyl group having 2 to 5 carbon atoms. A content of 1-methylpyrrolidine in the molten-salt electrolyte is 100 ppm by mass or less.

Dependencies are inferred from the claim text.