A Co-Simulation Method Based on Coupled Thermoelectric Model for Electrical and Thermal Behavior of the Lithium-ion Battery

Abstract

Nowadays, the lithium-ion battery (LIB) has been widely used as an energy source for electric vehicles or the auxiliary power supply for rail transit. However, the sensitivity of LIB to temperature greatly limits its application condition. Due to internal impedance and entropy change, temperature of LIB varies during charging and discharging. This variation conversely affects the electrical characteristics of batteries, and then the heat generation rate. In order to accurately model this coupled thermoelectric process of the lithium-ion battery, a co-simulation method based on coupled thermoelectric model is developed in this paper, which combines equivalent circuit model (ECM) and Computational Fluid Dynamics (CFD) software. For purpose of verifying the feasibility and accuracy of the proposed method, Experiments are performed at different temperatures and C-rates conditions, using a large-format pouch cell applied in rail transit projects. The comparison indicates that this method joined with temperature correction has higher accuracy than the traditional thermal simulation without temperature correction and the simulated result shows good agreement with measurements.

Keywords

• Lithium-ion battery
• coupled thermoelectric model
• co-simulation method