Electric vehicle is the key direction of the development of new energy vehicles. Its core component is power battery pack, which is responsible for providing the power of the vehicle and the energy supply of on-board equipment. At present, the power used by the mainstream electric vehicles in the market is the power battery pack composed of the 18650 standard lithium iron phosphate battery. The 18650 lithium battery has the advantages of high energy density, good stability, low cost and high reliability. However, 18650 lithium battery also has a very big disadvantage is that it generates large heat during work. If the battery working temperature is too high, the battery discharge speed will be too fast and the endurance of electric vehicle will be affected.

The liquid cooling part of power lithium battery pack consists of liquid cooling tube and thermal conductive silicone gasket. The liquid cooling tube includes the internal coolant, which mainly completes the heat dissipation of the heat generated by the work of the lithium battery. The thermal conductive silicone gasket mainly completes the heat conduction between the electric cell and the liquid cooling tube. The selection of thermal conductivity silicone gasket is an important consideration factor in thermal design of power lithium battery, which usually has the following requirements:

1) In order to complete the good heat transfer between the electric core and the liquid cooling tube, the thermal conductivity material is required to have high thermal conductivity.
2) The gap between the core and the liquid cooling tube is filled with the thermal conductive gap filling material. Only under a certain pressure can the gap be guaranteed without air residue. Therefore, the thermal conductive material is required to have low thermal resistance and not affect the heat transfer under a certain pressure.
3) As a part of electric vehicles, power lithium battery requires thermal conductivity materials to meet automotive application temperature standards.