Structurally resolved Lattice Boltzmann simulations of battery systems

Abstract

Theoretical modeling and computational simulations are important approaches to gain a detailed insight into mesoscopic processes that are hard to study experimentally. Regarding lithium-sulfur batteries, several one-dimensional continuum models are published in the literature, which focus mainly on charge and discharge processes [1,2], e.g. the dissolution and precipitation of solid Li2S and S8 [3], as well as degradation mechanisms, such as the polysulfide shuttle. However, those models lack from dimension-related details such as the influence of the effect of the cell geometry and the electrolyte distribution as well as the electrolyte content [3,4]. Therefore, in our current research, a structurally resolved three-dimensional battery model is developed based on the Lattice Boltzmann method. The model will be applied to study the following aspects in the context of battery technology: (1) wetting processes during the electrolyte filling of realistic three-dimensional porous battery electrodes; (2) multi-species transport through the three-dimensional porous electrode; (3) chemical reactions such as dissolution and precipitation of species at the electrode surface. As part of the present poster, besides the methodological background, first interesting results as well as the future steps in model development will be presented. All in all, it is shown that the Lattice Boltzmann method is especially useful for understanding phenomena on the pore-scale of lithium-sulfur batteries and, thus, is a promising tool for the optimization of different aspects related to battery production, performance, and lifetime.

[1] K. Kumaresan et al.; J. Electrochem. Soc., 155 (8) (2008), pp. A576 [2] M. Marinescu et al.; Phys. Chem. Chem. Phys., 18 (1) (2016), pp. 584-593 [3] T. Danner et A. Latz; Electrochim. Acta, 322 (2019), pp. 646-656 [4] T. Li et al.; Adv. Funct. Mater., 29 (32) (2019), pp. 1-56