| abstract |
The invention discloses a high-density silicon-carbon negative electrode material with multiple mixed coating and a preparation method thereof, which overcomes the defects of uneven carbon coating on the surface of the current silicon-carbon material and is difficult to complete, and solves the problem of silicon carbon through a simple method. It is difficult to improve the compaction density of carbon anodes. The silicon carbon negative electrode material includes: primary particles and secondary particles, the primary particles are porous silicon carbon materials, the porous silicon is uniformly dispersed in the activated carbon, and the surface of the porous silicon and the activated carbon is coated with a layer of pyrolytic carbon with a thickness of 3-50 nm The coating layer, in which porous silicon accounts for 5-50% of the mass of the primary particles, activated carbon accounts for 20-30% of the mass of the primary particles, and pyrolytic carbon accounts for 20-75% of the mass of the primary particles; the secondary particles are the primary particles and graphite uniformly dispersed The agglomerates formed in the pyrolytic carbon have a particle size of 5-100um, the total carbon content of the silicon carbon negative electrode material is 80-90%, and the compaction density is 1.1-1.7g/cm 3 . |