Layered thermal model with sinusoidal alternate current for cylindrical lithium-ion battery at low temperature

The poor battery discharging performance and capacity, operated at low temperature, pose a technical barrier limiting their use in electric vehicles. Therefore, the purpose of this paper is proposed to improve the performance of battery at low temperature. And a sinusoidal alternate current (SAC) heating strategy is proposed to heat the battery. The battery is heated fast and uniformly, due to a large amount of heat generated at the inside of battery when sinusoidal alternate current is transited in a battery. Meanwhile, a layered thermal model is established to simulate the heating method. The SAC heating experimental results show that a lower frequency SAC within the scope of 100 Hz can heat battery effectively. And the simulation results show that the temperature error between outer layer of simulation and experimental tested actual surface temperature is no more than 1 °C. After heated by SAC at low temperature (−20°C), the battery capacity is promoted 45%. The proposed heating strategy is of great potential for rapidly improving operating performance of electric vehicles in cold weather. Furthermore, the confirmed layered thermal model could be applied to the investigation of lithium-ion battery.