ELECTROLYTE FOR ELECTRIC DOUBLE-LAYER CAPACITOR

摘要

PURPOSE: To enhance electrolyte in electrical conductivity and electrochemical stability by a method wherein quarternary ammonium salt is dissolved as solute into non-aqueous solvent which contains aliphatic monocarboxylic acid ester whose total number of carbon atoms is four and propylene carbonate. CONSTITUTION: A mixed solvent is composed of 10 to 50wt.% aliphatic monocarboxylic acid ester and 90 to 50wt.% propylene carbonate. Quarternary ammonium salt such as triethylmethylammonium borofluoride or triethylmethylammonium phosphorofluoride is used, and either or a mixture of them is made to serve as solute. Quarternary ammonium salt as solute is set to 0.5 to 2.0 in molar concentration. By this setup, electrolyte of this constitution is enhanced in electric conductivity.