Application of high frequency square wave pulsed current on lithium-ion batteries at subzero temperature

Abstract

The performance degradation of lithium-ion batteries in low-temperature environments significantly impedes their application in power battery and electrochemical energy storage sectors. This study investigates the application of HF (high-frequency) square-wave pulsed current to mitigate capacity degradation and charging/discharging challenges in lithium-ion batteries at subzero temperatures. Initially, an electrochemical impedance-thermal coupling model, applicable to the preheating of pulsed currents across the full frequency spectrum, is formulated. Subsequently, the model parameters are ascertained through the design of thermo-physical experiments and an enhanced particle swarm optimization algorithm. The investigation proceeds to examine the impact of HF pulsed current parameters on the preheating and aging of cells with varying initial SOC (State of Charge). Experimental outcomes reveal that the temperature estimation error is confined to within 1.5 °C for pulsed amplitudes of 5A, 7A, and 9A, at a pulsed frequency of 2.5 kHz and an ambient temperature of −17 °C. Comparative assessments of the influence of HF pulsed current parameters on low-temperature warm-up rates and battery longevity demonstrate minimal capacity loss across batteries with differing SOCs. Specifically, at a pulsed current of 3.6C, the capacity retention rate surpasses 96 % after 50 heating cycles. The optimization of pulsed current parameter design, in conjunction with pulsed charging applications, presents practical significance and furthers the exploration of low-temperature applications for HF pulsed operation in lithium-ion batteries.