| 摘要 |
A negative electrode active material for non-aqueous electrolyte secondary batteries including a silicon material is provided which is capable of forming a non-aqueous electrolyte secondary battery exhibiting high charging capacity and initial charge/discharge efficiency, and excellent cycle characteristics. A negative electrode active material particle (10) according to one embodiment of the present invention is provided with: a lithium silicate phase (11) represented by Li2zSiO(2+z) {0<z<2}; and particles (12) which are dispersed in the lithium silicate phase (11), and which each include a core particle (15) comprising silicon (Si), and a surface layer (16) comprising an Si-containing iron alloy (an FeSi alloy). In an X-ray diffraction (XRD) pattern obtained by subjecting the negative electrode active material particle (10) to an XRD measurement, the half-value width of the diffraction peak of the FeSi alloy in the vicinity of 2θ=45˚ is at least 0.40˚, and the half-value width of the (111) plane diffraction peak of Si in the vicinity of 2θ=28˚ is at least 0.40˚. |
