Electrolyte for battery

摘要

A battery capable of inhibiting decrease in capacity and inhibiting swollenness even in hot environment is provided. A battery comprises a cathode (21), an anode (22) and an electrolyte (24) inside a film exterior member. The electrolytic solution contains carboxylate ester or ketone, in which a third alkyl group is directly bonded to a carbonyl group. Thereby, decomposition reaction of the solvent in the cathode is inhibited.