Negative electrode active material for non-aqueous electrolyte secondary battery and manufacturing method thereof

A negative electrode active material for non-aqueous electrolyte secondary battery, the negative electrode active material comprising:

• a silicon oxide composite comprising silicon, a silicon oxide (SiOx, 0<x≤2), and a magnesium silicate,
• wherein the magnesium silicate includes MgSiO3, and the negative electrode active material has a ratio of a diffraction peak intensity of MgSiO3, denoted as IMgSi03(610) and detected at 2θ=30° to 32° to a diffraction peak intensity of Si(111), denoted as Isi(111) and detected at 2θ=27.5° to 29.5°, in X-ray diffraction analysis, such that 0.1<IMgSi03(610)/Isi(111)<0.3,
• wherein the silicon of the silicon oxide composite is dispersed in a matrix comprising silicon oxide and the magnesium silicate,
• wherein the silicon oxide composite further comprises a carbon-containing coating layer on a surface thereof,
• wherein the silicon oxide composite comprises 2 to 20 parts by weight of the carbon-containing coating layer per 100 parts by weight of the total silicon oxide composite, and
• wherein the average thickness of the carbon-containing coating layer is from 1 nm to 2 μm.