Comparison between detailed model and simplified models of a Li-ion battery heated at low temperatures

Abstract

With the development of hybrid electric vehicles (HEVs) and electric vehicles (EVs), more and more attention has been paid to Li-ion batteries (LIBs). Since the charge-discharge performances of LIBs are affected by the temperature, an effective thermal management system is the key to solve the problem. Therefore, it is necessary to establish different simulation models to simulate the effects of the various thermal management systems. The prismatic pouch LIB cell is composed of multiple cell units connected in parallel, to reduce the calculation, the simplified models are used to simulate the LIB. In this paper, one detailed model and two simplified models are established to simulate temperature uniformity of heating LIB cells, and heating methods are the self-heating LIB structure heating method (SHLBHM) and the wide-line metal film heating method (WLMFHM). The simulation results of the detailed model and two simplified models are compared and analyzed. The results show that there are difference between the detailed model and two simplified models about temperature difference of the LIB cell, and the two simplified models have the same simulation results. Finally, the simulation results of the detailed models with different footprint areas are compared. The comparison results show that different footprint areas have no effect on the simulation results for both the self-heating LIB structure heating method and the wide-line metal film heating method.