Patent ID: 10312516

Abstract:
A negative-electrode active material for a non-aqueous electrolyte secondary battery containing a silicon material, wherein the negative-electrode active material can constitute a non-aqueous electrolyte secondary battery having high charge capacity, high initial charge/discharge efficiency, and good cycle characteristics. A negative-electrode active material particle according to an embodiment includes a lithium silicate phase represented by Li2zSiO(2+z) {0<z<2} and particles dispersed in the lithium silicate phase. Each of the particles includes a silicon core particle and a surface layer formed of an iron alloy containing Si (FeSi alloy). In an XRD pattern of the negative-electrode active material particle obtained by XRD measurement, a diffraction peak of the FeSi alloy at 2θ=approximately 45 degrees has a half-width of 0.40 degrees or more, and a diffraction peak of a Si (111) plane at 2θ=approximately 28 degrees has a half-width of 0.40 degrees or more.