Thermal Regulation Fast Charging for Lithium-Ion Batteries

Fast charging of lithium-ion batteries can shorten the electric vehicle's recharging time, effectively alleviating the range anxiety prevalent in electric vehicles. However, during fast charging, lithium plating occurs, resulting in loss of available lithium, especially under low-temperature environments and high charging rates. Increasing the battery temperature can mitigate lithium plating, but it will also aggravate other side reactions of aging, thereby contributing to the degradation of usable capacity and increasing potential safety hazards. This paper studies a commercial 18650 NCM lithium-ion battery and proposes a universal thermal regulation fast charging strategy that balances battery aging and charging time. An electrochemical coupling model considering temperature effects was built to determine the relationship between the allowable charging rate of the battery and both temperature and SOC (state of charge). Then the Pareto frontier is calculated using the NSGA-II algorithm, with the lithium plating boundary as the constraint and the battery aging and charging time as the optimization objectives. By weighing the battery aging and charging time, the temperature control strategy for the fastest charging speed when the battery meets the aging requirements is obtained.