Patent ID: 11831007

Abstract:
A Si-based negative electrode active material that is capable of improving cycle characteristics, reducing or eliminating a plateau region in the discharge profile, and further improving high-rate characteristics. The Si-based negative electrode active material contains Si and a compound containing Si and a semimetal/metal element M, wherein the content of Si in the negative electrode active material is more than 50 wt %; the content of oxygen atoms (O) is less than 30 wt %; the content of the semimetal/metal element M is more than 10 wt % and less than 50 wt %, wherein in an X-ray diffraction pattern as measured by a powder X-ray diffraction (XRD) device using Cu-Kα1 rays, the full width at half maximum of the peak of the (111) plane of Si is 0.25° or more; and wherein the peak intensity of the peak of the (111) plane of Si is less than 20,000 cps; and the true density is 2.5 g/cm3 or more.