NEGATIVE ELECTRODE ACTIVE SUBSTANCE FOR NONAQUEOUS ELECTROLYTE SECONDARY CELL, NEGATIVE ELECTRODE FOR NONAQUEOUS ELECTROLYTE SECONDARY CELL, NONAQUEOUS ELECTROLYTE SECONDARY CELL, AND METHOD FOR PRODUCING NEGATIVE ELECTRODE MATERIAL FOR NONAQUEOUS ELECTROLYTE SECONDARY CELL

摘要

The present invention is a negative electrode active material for a non-aqueous electrolyte secondary battery, including negative electrode active material particles containing a silicon compound (SiO x where 0.5‰¤x‰¤1.6), the negative electrode active material particles being coated with a carbon coating composed of a substance at least partially containing carbon, the carbon coating having a density ranging from 1.2 g/cm 3 to 1.9 g/cm 3 , the negative electrode active material particles having a characteristic of type II or type III adsorption-desorption isotherm in the IUPAC classification, as obtained by adsorption-desorption isotherm measurement with nitrogen gas. This negative electrode active material can increase the battery capacity and improve the cycle performance and battery initial efficiency.