NEGATIVE ELECTRODE ACTIVE MATERIAL FOR SECONDARY BATTERIES, AND SECONDARY BATTERY

The purpose of the present disclosure is to improve the cycle characteristics of a secondary battery that uses an Si-based active material containing Si. A negative electrode active material (Si-based active material) for secondary batteries according to one embodiment of the present invention comprises core particles, each of which is obtained by dispersing Si particles in a silicon oxide phase or a silicate phase, and a carbon material that adheres to the surfaces of the core particles. If a D/G ratio is the ratio of the peak intensity of the D-band to the peak intensity of the G-band in the Raman spectrum, the carbon material contains a first carbon material that has a D/G ratio of from 0.8 to 2 and a second carbon material that has a D/G ratio of from 0.01 to 0.5. The D/G ratio of the carbon material is from 0.2 to 0.9.