A Numerical Operando Approach for Lithium-Sulfur Batteries Based on Firedrake

Kurzfassung

Lithium-sulfur batteries are believed to be a promising candidate for aerospace applications considering their exceptionally high theoretical gravimetric energy density. However, this metric is just one side of the medal. On the other side, aerospace applications usually require a high-power demand for certain flight maneuvers. Experimental data for traditional sulfur–carbon composite cells point at the conclusion that matching both of these requirements, namely high energy density and high power, seems conflicting. There is a consensus that kinetic limitations as well as blockage and passivation effects are more pronounced for higher sulfur loadings. Still, even considering cutting-edge experimental operando methods, the understanding of these processes and their feedback on the cell performance is yet incomplete. Motivated by this, we present a simulation workflow based on the open-source tool Firedrake to support the development of optimized electrode design balancing energy and power density. Our workflow, which we call numerical operando approach, is an efficient partially scale-resolved three-dimensional continuum approach inferred from experimental data. The approach will be discussed alongside with the role of standard homogenized 1D models in order to consistently define detailed 3D models. The importance of appropriate closure models will be highlighted as well, eventually being critical for the success of detailed zoom-in simulations.