▎ 摘　　要

NOVELTY - Modified lithium ion battery anode material comprises a core-shell structure, which includes a lithium ion battery anode material core, a polycation polymer layer and a graphene oxide layer from the inside to the outside. The surface of the anode material of the lithium ion battery is negative. USE - The modified lithium ion battery anode material is useful for lithium ion battery (claimed). ADVANTAGE - The node material has excellent cycle stability, stable charge and discharge, and a low degree of capacity decline after multiple charge and discharge, very small amount of graphene oxide can be used to modify the anode material of lithium ion batteries, which improves the cycle stability of the anode material, is suitable for a variety of lithium ion battery cathode materials, has a wide coating range and strong applicability and can carry out multi-layer coating according to demand, and the coating thickness can be adjusted. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) a modified lithium ion battery cathode material, comprising a core-shell structure, which includes lithium ion battery cathode material core, polyanionic polymer layer, polycationic polymer layer and graphene oxide layer from the inside to the outside, where the surface of the cathode material is positively charged; and (2) preparation method of modified lithium ion battery anode material, comprising (i) detecting the electrical properties of the surface of the anode material of the lithium ion battery, (ii) when the surface of the anode material of the lithium ion battery is negatively charged, coating the anode material of the lithium ion battery using polycation polymer to obtain polycation polymer layer on the surface of the anode material of the lithium ion battery and coating graphene oxide layer on the surface of the polycationic polymer layer, and (iii) when the surface of the anode material of the lithium ion battery is positively charged, coating the anode material of the lithium ion battery using a polyanionic polymer to obtain polyanionic polymer layer on the surface of the anode material of the lithium ion battery, covering the surface of the polyanionic polymer layer with a polycationic polymer layer, and covering the surface of the polycationic polymer layer with a graphene oxide layer.