A record fast ACP self-heating for lithium-ion batteries without capacity loss based on electrochemical-thermal coupling model

Lithium-ion batteries exhibit a notable decline in performance at low temperatures, including capacity reduction and impedance growth. Therefore, adopting an alternating current pulse (ACP) self-heating is a viable approach for improving battery performance at low temperatures. However, improper selection of ACP amplitude and frequency may induce capacity loss during heating. To overcome this challenge, a novel electrochemical-thermal coupling (ETC) model has been constructed by simultaneously considering the double layer and lithium plating, and combining model accelerated computation. The model can efficiently and accurately calculate capacity loss and temperature rise of batteries under high-frequency (> 10 Hz) currents. The effects of ACP self-heating on the batteries are analyzed using the model, revealing the mechanism by which the combined effects of ACP frequency and amplitude contribute to lithium plating during self-heating. Furthermore, a Bayesian optimization framework is established by combining the model to effectively identify the optimal ACP parameters at different temperatures, accompanied by the proposal of a self-heating strategy that adapts to temperature variations. The self-heating strategy can enhance the temperature rise rate while eliminating capacity loss due to lithium plating. The experimental validation illustrates that batteries can be rapidly heated from −20 °C to 11.1 °C within five minutes via the optimized strategy without capacity loss after 90 heating cycles. The proposed self-heating strategy achieves a record fast battery temperature rise compared to other studies.