An Image Based 3D Modelling Framework for Li-S Batteries

Abstract

Abstract Lithium Sulfur batteries the represent the next generation battery chemistry that is closest to commercialisation. Having particular advantages in gravimetric energy density, they still suffer from low-rate performance and capacity fade, linked to the complex multi-step electrochemistry and heterogenous electrode structures. Physics-based models of batteries have long been used to understand and predict their behaviour; traditionally, 1D volume-averaged continuum approaches are used, not accounting for the heterogenous structure of the electrode. For the first time, we present a three-dimensional electrochemical model of a Li-S battery based on real electrode microstructure. The extent of heterogeneities present in the electrode architecture and the adequacy of using the representative elementary volume to capture the effect of complex electrode microstructure on the cell performance were analysed and compared with the 1D model. Finally, the future modelling framework that would aid in optimising the S/C structure for improved and uniform cell performance is discussed.