Design of cooling system for lithium ion battery at different discharge rates with thermal electrical modeling

Using renewable energies instead of fossil fuels can reduce environmental problems. In this way, batteries can play an important role as energy storage. Lithium-ion batteries have been very much considered in recent years due to their high energy density and long life time. The use of electric vehicles is increasing to prevent air pollution in various countries. In these cars, electric motors that work with batteries are used instead of internal combustion engines. In this paper, a lithium-ion battery was modeled electrically and thermally. It was indicated the temperature increase and the battery voltage decrease in discharging process. The numerical solution of the energy and electrical equation was made using a finite volume method in computational fluid dynamics. The results showed that when the battery is discharged at a discharge rate of 1c, the battery temperature reaches 54°C and at a discharge rate of 2c, the battery temperature reaches 83°C, which can damage the battery. To avoid this problem, a cooling system was designed which, with a flow rate of 0.2 m / s and 25°C at a discharge rate of 1c cooled battery to 31°C and at a discharge rate of 2c to 40°C. To increase cooling, with a flow rate of 0.2 m / s used a temperature of 15, in this condition the temperature of the battery at discharge rate of 2c reached a discharge temperature of 37°C, which falls within the permissible range.