Negative active material and preparation method thereof, negative pole piece, battery and electric equipment

The invention discloses a negative active material and a preparation method thereof, a negative pole piece, a battery and electric equipment, and relates to the field of batteries. The negative electrode active material comprises a silicon core, a silicon nitride layer coated on the surface of the silicon core, and a carbon layer coated on the surface of the silicon nitride layer, and the particle size of the negative electrode active material is nanoscale. According to the negative electrode active material, the current situation that an existing silicon-based negative electrode active material is poor in rate capability and short in service life is relieved through cooperation of the structure, the material and the particle size, and the negative electrode active material has excellent cycling stability and rate capability. 本申请公开了一种负极活性材料及其制备方法、负极极片、电池和用电设备，涉及电池领域。负极活性材料包括：硅核，包覆于硅核的表面的氮化硅层，以及包覆于氮化硅层的表面的碳层，负极活性材料的粒径为纳米级。该负极活性材料利用结构、材料以及粒径的配合，缓解现有硅基负极活性材料的倍率性能差及寿命低的现状，具有优异的循环稳定性能以及倍率性能。