An optimal self-heating strategy for lithium-ion batteries with pulse-width modulated self-heater

Battery self-heating technology has emerged as a promising approach to enhance the power supply capability of lithium-ion batteries at low temperatures. However, in existing studies, the design of the heater circuit and the heating algorithm are typically considered separately, which compromises the heating performance. In this paper, an optimal self-heating strategy is proposed for lithium-ion batteries with a pulse-width modulated self-heater. The heating current could be precisely controlled by the pulse width signal, without requiring any modifications to the electrical characteristics of the topology. Meanwhile, the heating process is further optimized with a particle swarm optimization algorithm to balance the heating time and energy efficiency. The effectiveness of the proposed heating strategy is validated on the designed self-heater. Experimental results show that the proposed heating strategy can effectively shorten the heating time by at least 12.5% and improve energy efficiency by more than 3.4% when compared with existing heating strategies. Moreover, no obvious capacity fade is observed after 500 repeated heating processes.