Simulation and experimental research on the lithium-ion battery thermal behavior considering discharge rate and ambient temperature

Thermal behavior is a key factor in lithium-ion batteries, and it is highly sensitive to discharge rate and ambient temperature. A single lithium-ion battery testing platform was constructed to obtain thermodynamic parameters of lithium-ion batteries at different discharge rates and ambient temperatures. Based on the experimental results, internal resistance and discharge capacity are selected as the optimization target parameters, and the internal resistance correlation and discharge capacity correlation considering the impact of discharge rate and ambient temperature are fitted. The optimized model was verified with experimental battery temperature. Compared with the Bernardi model, the Mean Absolute Percentage Error (MAPE) between the simulation and experimental results decreased from 11.4% to 6.0%, and the accuracy improved by 47.4%.