MANUFACTURING METHOD OF NEGATIVE ELECTRODE MATERIAL FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To manufacturing a negative electrode material of a good cycle life, wherein fine powder formation is suppressed by using a high theoretical capacity as a negative electrode material for a nonaqueous electrolyte secondary battery. SOLUTION: Alloy powder obtained by solidifying is fusion raw material of the composition which is designed to precipitate while an intermetallic compound of Si and Si are being solidified (lower in temperature than the alloy's liquid curve temperature, +500 deg.C) by means of a gas atomization method is made to be the negative electrode material wherein one kind or more chosen from Ar, He and N2 is used as a spray gas. Particle size is controlled so that the powder particle diameter D(μm) not less than 80 vol% of alloy powder satisfies a formula D <=[(2.5a-10b-3.8c)×102]1/1.5. In the formula, a b and c are respectively the volume fractions of Ar, He and N2 in the spray gas, and a+b+c=1.