A novel semi-analytical solution for calculating the temperature distribution of the lithium-ion batteries during nail penetration based on Green's function method

Lithium-ion batteries are now becoming the primary energy storage device for electric vehicles. However, thermal runaway caused by the internal short circuit in lithium-ion batteries draws attention to the safety issues. The dramatic temperature change of lithium-ion batteries can lead to fatal accidents. This paper aims to find a better way to estimate the lithium-ion batteries' temperature distribution under the nail penetration condition. Then a semi-analytical solution based on Green's function is derived at three different punching positions. A three-dimensional battery model is constructed by utilizing COMSOL Multiphysics software to simulate the characteristics of temperature distribution's variation. The results show that the temperature distribution is related to the nail penetration position. When the punching position is near to the positive electrode of the battery, the temperature can reach the highest value compared with the other two nail penetration positions, the middle of the battery and the position that is far from the positive electrode. In addition, the simulation results are compared with the temperature curve drawn by solving the semi-analytical solution. It shows that these temperature curves follow a similar trend, and the difference between the simulation results and the semi-analytical solution is small with an error less than 5%.