Electrochemical and thermal coupled modeling of high power lithium ion battery

An electrochemical-thermal coupled model was developed for high power lithium ion batteries based on the porous electrode and concentrated solution theory. The model allows for predicting the distribution of reaction current density in electrodes and temperature gradient inside the battery, and also for simulating the dynamic responses of the battery's terminal voltage and the transient changing processes of the surface temperature of the battery. To verify the validity of the model, the terminal voltage response processes of a 3.6V/8Ah lithium ion battery during 10s pulse charge/discharge with various current magnitudes, and the surface temperature of the battery under different cooling conditions were measured based on Arbin test bench. The experimental results indicate that the relative errors of the predicted terminal voltage are less than ±1% when the pulse time exceeds 1s, and the deviations of the simulated surface temperature from the measured one are not bigger than 1°c.