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

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a negative electrode active material comprising silicon particles as an active material effective for a negative electrode of a nonaqueous electrolyte secondary battery that is excellent in cycle characteristics and has a reduced volume change in charge/discharge while maintaining a high initial efficiency of silicon and battery capacity.SOLUTION: A method for producing a negative electrode active material for a secondary battery using a nonaqueous electrolyte comprises at least vapor-depositing a metal silicon material on a substrate at a controlled temperature of 300-800°C under reduced pressure to have silicon accumulated, and pulverizing and classifying the accumulated silicon.