An Internal Heating Strategy for Lithium-Ion Batteries Without Lithium Plating Based on Self-Adaptive Alternating Current Pulse

AC pulse heating is a promising preheating method for lithium-ion batteries due to its low energy cost and high efficiency. To avoid the lithium plating in the AC heating, upper bound of heating current (UBHC) should be obtained. In this paper, the dual RC model is developed, and coupled with the thermal model to predict the battery temperature and potential of negative electrode (PNE). PNE = 0 V is used as the lithium plating criteria. If the PNE falls to 0 V during the heating process, the lithium plating is triggered, and the corresponding pulse amplitude is the UBHC. Moreover, because the UBHC increases with the battery temperature, the pulse amplitude should be automatically raised to increase the heating efficiency. When the battery temperature is too low, the UBHC is so small that the AC pulse heating is inapplicable. Through the self-adaptive AC pulse based on the UBHC, the heat strategy is built, and the heating time is calculated. The total heating time reached by the proposed strategy increases with the increment of the initial SOC, and it falls with the decrease of the initial battery temperature. Moreover, the heating time has a temperature limit. If the battery temperature is lower than the limit, the battery cannot be heated to the target temperature in the required time. The proposed strategy is applied to heating the battery at the different SOCs, and its performance is compared to the constant amplitude pulse. In the same heating time, the battery temperature achieved by the proposed strategy is at least 7.6 degrees C higher than the constant amplitude pulse. Moreover, the UBHC is enlarged by 10% to prove the original UBHC can reduce the degradation. The cyclic heating experiment shows that the 110% UBHC reaches a capacity loss of 0.49 Ah after 60 heating cycles and that of the original UBHC is only 0.1 Ah.

Automated summary

AC pulse heating is a low-energy and high-efficiency preheating method for lithium-ion batteries. In this study, a dual RC model and a thermal model were used to predict the battery temperature and negative electrode potential. The upper bound of heating current (UBHC) was determined by the criteria of negative electrode potential reaching 0 V, indicating lithium plating. The proposed self-adaptive AC pulse heating strategy improved the heating efficiency compared to constant amplitude pulse heating.