▎ 摘　　要

NOVELTY - Silicon-based composite material comprises a particle consisting of an inner core and a first shell layer existing on the surface of the inner core. A second shell layer exists on the surface of the particle. The inner core comprises a silicon-oxygen material. The first shell layer includes a silicon carbide (SiMC) material containing silicon element, M element, and carbon element. The M element includes Group IIIA, Group VA or Group VA in the periodic table of elements, and group VI elements. The second shell layer includes a carbon material. USE - Silicon-based composite material for cathode sheet used in electrochemical device and electronic device. ADVANTAGE - The silicon-based composite material has good structure stability and conductivity, which is good for being used as the function material, solves the problem that the electrochemical device in the circulation process of volume expansion, poor circulation, improves the conductivity and structural stability of silicon-based materials, and determines the properties of the silicon-based composite material. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) a negative electrode sheet, which comprises a negative electrode current collector and a negative electrode active material layer positioned on surface of the negative electrode current collector, the negative electrode active material layer contains a negative electrode active material, and the negative electrode active material includes a negative electrode active material; (2) an electrochemical device, which comprises the negative electrode sheet; and (3) an electronic device, which comprises the electrochemical device.