Method for producing porous silicon electrode active material particles, porous silicon electrode active material particles, electrode mixture, and battery

Abstract

The present disclosure provides a method for producing porous silicon electrode active material particles in which expansion and contraction are suppressed and the initial charge-discharge efficiency of a battery can be improved, porous silicon electrode active material particles, an electrode mixture including such porous silicon electrode active material particles, and a battery including such an electrode mixture. The method of the present disclosure for producing porous silicon electrode active material particles includes: (a) reducing porous silica particles with magnesium to obtain precursor particles containing silicon and magnesium oxide; and (b) removing the magnesium oxide from the precursor particles. In the porous silicon electrode active material particles of the present disclosure, the oxygen concentration is 6.5 mass % or less, the ratio of the oxygen concentration, expressed in mass %, to the specific surface area expressed, in m2/g, is 0.050 or less, and the pore volume is 0.9 cc/g or more.

Dependencies are inferred from the claim text.