▎ 摘 要
NOVELTY - Carbon-coated composite material (c) is obtained by coating a surface of a composite material (a) containing a carbon material and silicon with a carbonaceous coating layer (b), where in the Raman spectrum of the carbon-coated composite material (c) by microscopic Raman spectroscopic analysis, the coefficient of variation of the ratio (ID/IG) of the R value (peak intensity (ID) near 1350 cm-1 to the peak intensity (IG) near 1580 cm-1) is 0.6 or less, and the coefficient of variation of the ratio (ISi/IG) of the 450-495 cm-1 to the peak intensity (ISi/IG) is 1 or less. USE - The material (c) is useful for a negative electrode active material, which is useful for a negative electrode for a lithium ion secondary battery (all claimed). ADVANTAGE - The material (c) suppresses deterioration of silicon by forming thin and uniform carbonaceous coating layer on the surface, and has excellent initial discharge capacity of lithium ions, initial coulomb efficiency and cycle characteristics.