124 / 2021-06-18 23:26:54

Deformation behavior of Lithium-ion battery using electrochemical-thermal-mechanical coupling model

Due to the characteristic of high energy density, long-life cycle and other special properties, LIB has been widely used in electrical vehicles and energy storage station [1,2]. However, in recent years, explosion accidents caused by the abuses of the batteries such as overcharge, short circuit, over heating occurred frequently. The safety of the LIB has become the vital problem to the further development of the LIBs. Among various of abuses conditions, overcharge is one of the most important common abuses for LIBs [3]. Therefore, investigating the performance of the LIBs under overcharge state is vital for ensuring the safety of the LIB. The establishment of theoretical model of LIB can achieve the prediction and control of the battery without the constraint of experimental conditions, which has become a key step in the performance research of LIB at present [4]. Among many models, the electrochemical model of the LIB is the most accurate one to describe the electrochemical performance of the battery. In this paper, To find out a more effective way to detect the overcharge of Lithium-ion battery (LIB), the electrochemical-thermal-mechanical coupling model of the LIB is constructed in the COMSOL Multiphysics using the LIB module, heat transfer module and mechanics module. The deformation of the LIB under different state of charge (SOC) including overcharge are studied using the coupling model. The simulation results are shown in Fig.1. When the LIB is overcharged, the deformation of the battery shell will increase, which can be used as an indicator to detect the overcharge of LIB. In addition, the temperature and deformation of the overcharged LIB under different charge currents and ambient temperature are studied using the coupling model, and the results shown in Fig.2 and Fig.3 indicate that both the charge current and the ambient temperature have some effect on the overcharged battery. With the increase of the charge current and ambient temperature, the deformation of the battery shell will increase and the rate of battery temperature rise will be larger. Therefore, it is of great significance to select the appropriate charge current and ambient temperature to ensure the safety of LIBs.