A variable PBC low temperature preheating strategy fully exploiting heat generation characteristics of lithium-ion batteries

Lithium-ion batteries are prone to lithium plating at low temperatures, which poses a threat to their health. To address this issue, a variable bidirectional pulsed current (BPC) method for rapid and nondestructive preheating is proposed. First, an electrothermal coupled model was developed, and parameter identification was performed using neural networks and polynomial fitting. To fully utilize the heat generation characteristics of both positive and negative pulses, BPC parameter calculation rules were subsequently established, and a rapid, nondestructive BPC heating strategy was designed using the developed model and rules. The experimental results demonstrate that the proposed method achieves preheating rates of 5.98 °C/min at a 40 % state of charge (SOC) and 3.18 °C/min at an 80 % SOC. After 300 thermal cycles, the charging capacity decreased by only 0.13 %, and the discharging capacity showed negligible loss, indicating that rapid and nondestructive heating was successfully achieved.