Degradation Effects in Metal-Sulfur Batteries

Kurzfassung

Metal–sulfur (Me–S) batteries are one of the most promising battery technologies and might even outperform future Li-ion batteries. However, these systems generally show a relatively fast capacity loss, low power density, and fast self-discharge. Furthermore, the underlying mechanisms are insufficiently understood, making it difficult to systematically improve cell performance. In the present study, we use a pseudo-two-dimensional continuum model to analyze the degradation behavior during cycling of Li–S and Mg–S batteries. The simulations reproduce charge and discharge curves of both systems and allow detailed investigations on the influence of material properties on degradation mechanisms. Special attention is paid to the redistribution of active sulfur during cycling and its effect on long-term stability. Finally, we demonstrate the application of the model for qualitative predictions of battery performance and lifetime of cathode designs with improved sulfur loading.