NEGATIVE ELECTRODE MATERIAL FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERY AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a negative electrode material for non-aqueous electrolyte secondary battery with high capacity and superior in overcharge resistance characteristics, and its manufacturing method.

SOLUTION: The negative electrode material for non-aqueous electrolyte secondary battery consists of compound particles of a solid phase A having silicon and a solid phase B having a crystalline alloy of silicon and a transition metal. An oxide film of silicon and an oxide film of the transition metal exist on the surface of the negative electrode material, and the proportion of the thickness of the oxide film of the transition metal to the thickness of the oxide film of silicon is 0.44 or more and less than 1. The negative electrode material is mechanically alloyed in an inert gas atmosphere, the oxide film is formed by introducing oxygen gas in the inert gas atmosphere, and the oxide film is grown by introducing steam to manufacture the material.

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