Negative electrode composite material, preparation method thereof and electrochemical device

The invention provides a negative electrode composite material, a preparation method thereof and an electrochemical device. The negative electrode composite material comprises a plurality of silicon crystal materials and conductive carbon materials; wherein the crystalline silicon material comprises a PN junction formed by connecting P-type silicon and N-type silicon, and the crystalline silicon material is dispersed in the conductive carbon material. The negative electrode composite material can show certain one-way conductivity, so that the negative electrode composite material has the characteristic of short circuit resistance, meanwhile, the invention also provides a negative electrode piece using the negative electrode composite material, and the negative electrode piece has conductivity along a specified direction, so that the negative electrode composite material can be used for providing an electrochemical device with relatively high safety performance. 本申请提供了一种负极复合材料及其制备方法、电化学装置。所述负极复合材料中包括多个硅晶材料和导电碳