Analytical techniques for studying cell aging in lithium–sulfur batteries

Abstract

Lithium–sulfur batteries (LiSBs) hold promise for future energy storage due to their high theoretical energy density, but practical use faces challenges like capacity loss, short cycle life, and poor rate performance, primarily due to sulfur's complex redox reactions and polysulfide dissolution. Despite these challenges affecting LiSBs’ lifespan and durability, post-mortem analysis of aged cells with physicochemical techniques is increasingly essential for studying batteries, identifying new species, and monitoring electrode health and energy stability. This review explores the literature on analyzing aged LiSBs, encompassing disassembly methodologies and techniques (microscopic, spectroscopic, and electrochemical) to characterize materials retrieved from aged batteries. This discussion explores how these techniques have been crucial in studying structural, morphological, and chemical changes in LiSBs during cycling, highlighting key findings and insights, while also addressing challenges and future directions in post-mortem analysis, emphasizing the need for advanced analytical methods and multi-modal approaches to unravel complex degradation mechanisms, ultimately advancing the LiSBs.