Chemical reactions in lithium-sulfur batteries

Abstract

The sulfur redox pathways in lithium-sulfur (Li-S) batteries involve an intricate 16-electron conversion process featuring multiple polysulfide intermediates. These polysulfides show high solubility and reactivity in ether-based electrolytes, leading to complex electrochemical and chemical reaction branches. Unlike the much-discussed electrochemical reactions, chemical reactions associated with polysulfides have been largely overlooked in the literature. Herein, we comprehensively summarize these polysulfide-associated chemical reactions with different components in Li-S batteries and discuss their crucial impacts on electrochemical performance. We also propose several notable scientific challenges from the perspective of chemical reactions in practical Li-S batteries and outline feasible strategies to address them for future research.