METHOD FOR PRODUCING SILICON OXIDE POWDER AND NEGATIVE ELECTRODE MATERIAL

WIPO Patent Application WO/2019/189747

A1

[Problem] To produce a silicon oxide-based negative electrode material which contains Li and has a C coating film on the surface and yet in which both intraparticle and interparticle Li concentrations are uniform and the formation of SiC is suppressed. [Solution] An Si and lithium silicate-containing starting material, which contains Si, Li and O and in which a part of Si exists as Si elements while Li exists as lithium silicate, is heated under reduced pressure to thereby generate an SiO gas and Li gas at the same time. Then the gases thus generated are cooled to give Li-containing silicon oxide having an average composition of SiLixOy (0.05