A negative electrode composite material includes a Si—M—C composite material. A conductive layer exists on a surface of the Si—M—C composite material, M includes at least one of boron, nitrogen, or oxygen. Chemical shifts of a silicon element in the Si—M C composite material as measured in a solid-state nuclear magnetic resonance test include −5 ppm±5 ppm, −35 ppm±5 ppm, −75 ppm±5 ppm, −110 ppm±5 ppm. A peak width at half height at −5 ppm±5 ppm is K, and K satisfies: 7 ppm