Thermal simulation and prediction of high-energy LiNi_0.8Co_0.15Al_0.05O₂//Si-C pouch battery during rapid discharging

Accurate thermal simulation of lithium-ion batteries is of great significance for evaluating and predicting the battery performance to avoid safety hazards. In this paper, research focused on the effects of current rates and ambient temperature on the thermal behavior of high-energy LiNi_0.8Co_0.15Al_0.05O₂//Si-C pouch battery is presented. The heat generation rate as a function of discharge rate is calculated by the means of electrochemical calorimetric study. Then by using the finite element analysis method, a three-dimensional model is developed to predict the battery temperature distribution at different discharge rates (0.33, 1.0, 3.0, and 5.0 C). The results reveal a minimum temperature difference of less than 1 °C between simulations and experiments even at 5.0 C rate. Notably, the increased rate leads to an enlarged temperature gradient field of battery, where the maximum battery temperature appears at its geometric center, then it gradually decreases from the center to edges in an annular gradient radiation manner. Accordingly, the simulation results provide a comprehensive evaluation and prediction for the thermal behavior of high-energy battery, which are well consistent with the experimental measurements.