基于区域电压的锂离子电池不均匀发热模型

The non-uniformity of the temperature spatial distribution of lithium-ion battery increases with the increase of the discharge rate, which seriously affects the battery life and safety. Aiming at the uneven temperature distribution during the discharge of lithium-ion battery, a new nonuniform heating model based on regional voltage is proposed to predict the battery temperature distribution in real time. Considering the battery size and thermal characteristics, the battery is divided into nine regions and the open circuit voltage test is carried out. The surface temperature change of each area is recorded in real time. Calculate the regional voltage using the surface temperature and ambient temperature data measured during every 10% of the state of charge (SOC) drops. Obtain the regional heat production of the battery according to the regional voltage, and establish a three-dimensional simulation model to obtain the spatial distribution of battery temperature. The non-uniform heating model is used to predict the spatial evolution of battery temperature when the discharge rate is 0.5C, 1C, 2C, 3C and 4C. The simulation results show that the model captures the uneven distribution of temperature. And the experimental results verify that the temperature errors are within 1℃, the relative errors are within 5%. It shows that the model can effectively monitor the temperature distribution.