SODIUM-ION SECONDARY BATTERY NEGATIVE ELECTRODE CARBONACEOUS MATERIAL AND SODIUM-ION SECONDARY BATTERY USING THEREOF

摘要

The purpose of the present invention is to provide a sodium-ion secondary battery having a high discharge capacity and having excellent cycling and preservation characteristics. The problems can be solved by a sodium-ion secondary battery negative electrode carbonaceous material characterized in that the ratio H/C of a hydrogen atom to a carbon atom determined by element analysis is 0.05 or less.