Parameter Sensitivity Analysis of Cylindrical LiFePO4 Battery Performance Using Multi-Physics Modeling

A multi-physics model for a cylindrical Li-ion battery has been developed by coupling a model of the thermal distribution in the radial direction to an electrochemical P2D model. The model can predict both terminal voltage and surface temperature, which has the advantage that it can be readily validated by measurement. A sensitivity analysis of up to 30 parameters was carried out using model simulation. A parameter sensitivity matrix was established to describe the parameter sensitivity under different operating conditions and clustering theory used to group the parameters according to their average sensitivity. Finally, a stepwise experiment was designed to validate the results of the sensitivity analysis. It was shown that the stepwise approach to parameter identification results in significantly higher accuracy.