Towards Rigorous Validation of Li-S Battery Models

TL;DR

This paper proposes a simple, predictive zero-dimensional model for Li-S batteries, along with validation procedures, to enhance understanding and standardize model evaluation in this promising energy storage technology.

Contribution

It introduces a new simple zero-dimensional Li-S battery model and a validation framework, with open-source implementation for widespread adoption.

Findings

Model outperforms existing models in key predictions

Validated with out-of-sample experimental data

Open-source code facilitates rapid modifications

Abstract

Achieving Li-S batteries' promise of significantly higher gravimetric energy density and lower cost than Li-ion batteries requires researchers to delineate the most important factors affecting the performance of this technology. By encoding this knowledge into a mathematical model, understanding is made precise, quantitative, and predictive. However, the complex and unknown mechanisms of Li-S batteries have multiple proposed models with relatively few informative quantitative comparisons to experimental data. Consequently, a minimum set of testing procedures for model validation is proposed. Moreover, in the absence of an accepted standard model, a zero dimensional model is proposed in this work. The model improves upon several existing models while remaining as simple as possible. The model is quantitatively predictive, as demonstrated by out-of-sample predictions of experimental discharge resistance. Finally, this model and others have been implemented using PyBaMM. Therefore, the open access code allows rapid modifications of this model by all researchers.