▎ 摘　　要

NOVELTY - Preparing silicon carbon material cathode based on functionalized polyethyleneimine and poly-dopamine copolymer comprises (i) adding ethanol dispersion of silicon nano-particles into deionized water, continuously ultrasonically dispersing and continuously stirring, at last, adding polyethylenimine solution, stirring to obtain the primarily functionalized silicon nano particle dispersion liquid, (ii) centrifuging polyethylenesimine poly-Dopamine/graphene oxide precursor for multiple times, washing with water, removing the redundant polyethylensimine-poly-dopedamine copolemer, dispersing to deionization water, (iii) ultrasonicating graphene oxide in the deionizing water to obtain a graphene oxide dispersion solution, (iv) dropping the washed polyethylenedopamine-functionalized silicon nanoparticle dispersion fluid to the graphene oxide dispersing solution, continue stirring, collecting precipitate by centrifugation. USE - Preparation method of silicon carbon material cathode for lithium ion battery. ADVANTAGE - The high specific capacity silicon carbon cathode material prepared by the method has good multiplying power performance and stability, and the technique is simple, and it has industrialization prospect. The method uses the special form of polyethylene imine trigger aggregate secondary functionalization treatment to the silicon nanometre particle. The graphene oxide with carboxyl on the surface is self-assembled by electrostatic attraction and hydrogen bond force under the liquid phase condition, the two are tightly combined such that the silicon particles are anchored on the graphene oxide layer, then reducing the carbon coating layer after the carbonization of the copolymer further ensures the interface combination degree of the silicon and the graphite, the nano silicon is not easy to fall off in the circulation and the stability of the material is ensured. DESCRIPTION OF DRAWING(S) - The drawing prepared according to Example 1 based on polyethylene imine and poly-dopamine copolymer functionalized high specific capacity silicon carbon material cathode different magnification of scanning electric mirror image.