NEGATIVE ELECTRODE ACTIVE SUBSTANCE FOR NONAQUEOUS ELECTROLYTE SECONDARY CELL AND NONAQUEOUS ELECTROLYTE SECONDARY CELL USING SUCH NEGATIVE ELECTRODE ACTIVE SUBSTANCE

摘要

The purpose of the present invention is to improve initial charge-discharge efficiency and cycle properties in a nonaqueous electrolyte secondary cell that uses SiOx as a negative electrode active substance. Provided is a negative electrode active substance for a nonaqueous electrolyte secondary cell that is particles formed from SiOx (0.5 ≤ X ≤ 1.5), wherein amorphous carbon is deposited on a carbon film. Preferably, the SiOx particle diameter is 1 to 15 µm and the amorphous carbon particle diameter is 0.01 to 1 µm. Preferably, 100 percent of the surface of the SiOx is coated by the carbon film.