Experimental Study on DC Pulse Discharge Preheating of Lithium Ion Batteries at low temperature over a wide frequency range

The severe degradation of Lithium-ion batteries (LIBs) performance at low temperatures needs to be recovered by preheating, while pulsed preheating is often considered as a good internal preheating method. In this paper, a heating experimental platform for Li-ion power batteries under pulse excitation is built, and the electrochemical impedance spectrum (EIS) and the convective heat transfer coefficient h of experimental 18650 Li-ion batteries are tested to carry out pulse excitation temperature rise experiments in the frequency range of 1Hz similar to 80kHz. The experiments show that the temperature rise rate of lithium-ion battery decreases with increasing frequency in the range of 1Hz-6kHz, and becomes faster with increasing frequency in the range of 6kHz-80kHz, which verifies the validity of the temperature rise model of lithium-ion battery.