Temperature Simulation for Prismatic Power Lithium-ion Battery based on Electrochemical-Thermal Coupling Model

Abstract

As one of the three core components of new energy vehicles, especially battery electric vehicles, lithium-ion power batteries have an important relationship with temperature during discharging and charging process, if the battery temperature is too high, it will affect the performance or even the safety of individual battery or the whole battery pack. In this paper, to investigate the battery thermal problem, the electrochemical-thermal coupling model based on NTGK model was built according to the principle of electrochemical reaction and heat production, and the key parameters U and Y in the NTGK model were obtained by fitting the experimental data, moreover, the battery material properties, boundary conditions and parameters were set in ANSYS Fluent software. Finally, the maximum temperature and temperature difference of the prismatic battery at 1C discharge rate was simulated by ANSYS. The simulation results show that the maximum temperature is 38.5 °C and occurs on the negative electrode ear of the battery, and the temperature gradient in the height direction of the battery is smaller, however, the temperature gradient in the length and thickness direction is larger. When the uneven temperature can easily cause local polarization in the battery, explosion risk increases with increasing discharge rates, and the established model could well reveal the battery’s temperature distribution during discharge.