Modelling Dynamic Limitations of Lithium Transport in Lithium-Sulfur Batteries

Abstract

A common, yet unmodelled experimental phenomenon is explained first through the experimental data and then through modelling efforts. The phenomenon is a large, temporary loss in voltage during constant current discharge. This effect can be observed in several independent experimental settings, such as during low-temperature operation, under high currents, with low Electrolyte-to-Sulfur (E/S) ratios, as well as in cells with high salt concentrations. The model presented here is the first to prove to capture this effect. Moreover, several other related experimental results are presented, discussed, and predicted by the model. A fundamental explanation for why most Li-S models are unlikely to be able to capture the large voltage loss effect is also given.