Computational Fluid Dynamics Modeling of Lithium/Thionyl Chloride Battery

Investigators:  W.B. Gu, C.Y. Wang, John Weidner (Univ. South Carolina), Ruldoph Jungst (Sandia)

A two-dimensional model is developed to simulate discharge of a primary lithium/thionyl chloride battery. The model accounts for not only transport of species and charge but also the electrode porosity variations and electrolyte flow induced by the volume reduction upon electrochemical reactions. Numerical simulations are performed using a finite volume method of computational fluid dynamics. The predicted discharge curves for various temperatures are compared to the experimental data with excellent agreement. Moreover, the simulated results in conjunction with computer visualization and animation techniques reveal that the cell performance in the parametric range of interest is limited by pore plugging at the front side of the cathode as a result of LiCl precipitation. The detailed two-dimensional flow simulation also shows that the electrolyte flow is predominantly in the horizontal direction from the separator to the cathode. This finding explains why an earlier one-dimensional model of Jain et al. (1998) accounting for unidirectional electrolyte flow is successful in predicting the cell discharge performance.

• Click here for a most recent manuscript prepared for submission to J of Electrochemical Society.
• Click here to view animated movies of electrolyte flow, reaction rate and porosity distributions.