At present

the automobile has become an indispensable transportation tool of work and life. At the same time the automobile also becomes the main source of environmental pollution. To save the energy

reduce the environmental pollution and realize sustainable development

the research of new energy vehicles has become the main trend and a basic policy of world's automobile production and usage. Temperature control of power battery is one of the key technologies of electric vehicle. The temperature control technology and thermal properties of PCM used in lithium batteries have been studied by scholars to solve the temperature instability and improve the safety performance of lithium batteries in new energy vehicles. By adding compounds such as metal

graphite and cellulose

the heat transfer performance of the battery had been improved. The mathematical equation of heat conduction established by computer simulation provides a theoretical basis for the application of PCM in lithium battery. In addition

the applications of PCM in energy recovery of vehicle exhaust and indoor temperature control are the research direction of vehicle energy saving. These process of indoor temperature control by PCM can be active or passive. This not only reduces the pollution during automobile operation

but also saves energy and enhances the safety of automobiles. Meanwhile

it keeps the temperature constant during the process of move and stop

and then the passengers will be more comfortable.