Document Type
Article
Abstract
The growing demand for high-energy-density batteries has renewed interest in lithium–sulfur (Li/S) systems, which offer significant advantages but suffer from severe self-discharge during rest. While prior studies attribute this degradation to chemical parasitic reactions or polysulfide shuttling, they overlook the inherently electrochemical nature of anode-side processes. In this work, a 1D physics-based model of a Li/S battery was developed to explicitly incorporate lithium-metal oxidation and the stepwise electrochemical reduction of polysulfides at the anode. Using COMSOL Multiphysics, galvanostatic discharge followed by open-circuit rest under two conditions was analyzed - with and without parasitic anode reactions. The results show that when anode reactions are excluded, species concentrations stabilize, and voltage remains constant during rest. In contrast, the inclusion of electrochemical reactions at the anode results in slow voltage decay and continued reduction of sulfur species, including the growth of lower order polysulfides and Li2S(s) precipitation. These findings reproduce key trends observed in experimental data. This study demonstrates that electrochemical anode reactions are central to self-discharge. Resolving these mechanisms through Faradaic kinetics yields a mechanistic foundation for predictive models and underscores the need to reconsider self-discharge as an electrochemically driven phenomenon.
Digital Object Identifier (DOI)
Publication Info
Published in Journal of The Electrochemical Society, Volume 172, Issue 7, 2025.
Rights
This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, https://creativecommons.org/licenses/by/4.0/)), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited.
APA Citation
Coman, P. T., & White, R. E. (2025). Modeling Self-Discharge in Li/S Batteries Through Electrochemical Anode Reactions: A Theoretical Perspective. Journal of the Electrochemical Society, 172(7), 070517. https://doi.org/10.1149/1945-7111/adeb32