▎ 摘　　要

NOVELTY - A composite coating comprises 0.5-2 parts mass ionic liquid, 0.5-2 parts mass lithium salt, 1-5 parts mass modified graphene and 10-20 parts mass binder. The ionic liquid is N-methyl-N-propylpiperidine bromide. USE - Composite coating is used in preparation of composite negative plate for lithium-ion battery (all claimed). ADVANTAGE - The lithium-ion battery obtained using the composite negative plate provided with the composite coating has excellent high-temperature performance such as cycle characteristics and storage performance. The composite coating improves the structural stability of solid-electrolyte interphase film and electrolyte at high temperature, and heat dissipation property of electrodes, and has high decomposition temperature and conductivity, and excellent thermal performance. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) composite cathode plate; and (2) preparation of composite negative plate.