The coating mold of lithium battery uses a special coating called coating agent. Coating agent is a high viscosity liquid, which usually consists of solvent, adhesive, filler and other additives. It has good fluidity and adhesion, and can be evenly coated on the anode and cathode materials of lithium batteries. In the coating process, the coating agent will be evenly coated on the pole piece of the lithium battery through the coating die. The adhesive in the coating agent will form a uniform film during the drying process, which will isolate the electrode sheet from the electrolyte and maintain the conductivity of the electrode sheet. Commonly used coating agents for lithium batteries are polyacrylonitrile (PAN) coating agent and polyacrylonitrile (PEN) coating agent. These coating agents usually have good chemical stability, electrical conductivity and mechanical strength, which can meet the requirements of lithium battery production.