NONAQUEOUS ELECTROLYTIC SECONDARY BATTERY

摘要

PURPOSE: To provide a nonaqueous electrolytic secondary battery in which the generation of a gas on the surface of a carbon material is prevented to prevent the leakage of an electrolyte due to the rising of the battery internal pressure and the expansion of the battery by using the carbon material whose surface is alkylated for a negative electrode. CONSTITUTION: In a nonaqueous electrolytic secondary battery formed of a negative electrode using a carbon material capable of storing and releasing lithium, a positive electrode and a nonaqueous electrolyte, the surface of the carbon material is alkylated. This alkylating treatment is preferably performed by adding 5-30wt.% of an alkylating agent such as trimethyl methoxysilane to the carbon material such as graphite and then thermally treating it under a prescribed condition. The surface of the carbon material is covered with the inert alkyl group and the gas generation by the decomposing reaction of the electrolyte or a binder at charging is suppressed.