NEGATIVE ELECTRODE MATERIAL FOR SECONDARY BATTERY WITH NON-AQUEOUS ELECTROLYTE, METHOD FOR MANUFACTURING NEGATIVE ELECTRODE MATERIAL FOR SECONDARY BATTERY WITH NON-AQUEOUS ELECTROLYTE, AND LITHIUM ION SECONDARY BATTERY

摘要

The present invention is a method for manufacturing a negative electrode material for a secondary battery with a non-aqueous electrolyte comprising at least: coating a surface of powder with carbon at a coating amount of 1 to 40 mass % with respect to an amount of the powder by heat CVD treatment under an organic gas and/or vapor atmosphere at a temperature between 800° C. and 1300° C., the powder being composed of at least one of silicon oxide represented by a general formula of SiOx (x=0.5 to 1.6) and a silicon-silicon oxide composite having a structure that silicon particles having a size of 50 nm or less are dispersed to silicon oxide in an atomic order and/or a crystallite state, the silicon-silicon oxide composite having a Si/O molar ratio of 1/0.5 to 1/1.6; blending lithium hydride and/or lithium aluminum hydride with the powder coated with carbon; and thereafter heating the powder coated with carbon at a temperature between 200° C. and 800° C. to be doped with lithium at a doping amount of 0.1 to 20 mass % with respect to an amount of the powder. As a result, there is provided a method for manufacturing a negative electrode material for a secondary battery with a non-aqueous electrolyte that enables a silicon oxide negative electrode material superior in first efficiency and cycle durability to conventional ones to be mass-produced (manufactured) readily and safely even in an industrial scale.