▎ 摘　　要

Polyacrylonitrile (PAN)-based carbon fibers are widely used as reinforcement materials and heating elements for their excellent mechanical and electric heating properties. But fiber oxidation at high temperature can easily cause electric heating device failure. Herein, the electrothermal effect of the carbon fiber modified by graphene epoxy resin coating was investigated, and the mechanism of electrothermal enhancement of the fiber was explored by detailed analysis of the surface structure and finite element simulation. The results showed that graphene coating and sintering under N-2 environment have effective protective effects on the carbon fiber, which greatly improves the electrothermal performance of the carbon fiber. Graphene coating-modified carbon fibers reached about 35 degrees C at 3 V within 20 s, and the equilibrium temperature is about 21% higher than that of the pristine carbon fiber. At the same time, in 20 electric heating and cooling tests at 5 V, the electric temperature can quickly reach 82 degrees C with good stability. Further simulation showed that the electrothermal performance may be enhanced by the current accumulation caused by the surface defect structure of modified carbon fibers. The modification method of graphene coating on carbon fiber surface presented in this paper is simple and easy to control and has great potential to be applied to industrial and civil electric heating equipment. [GRAPHICS]