An examination and prospect of stabilizing Li metal anode in lithium–sulfur batteries: A review of latest progress

Abstract

The Li metal anode emerges as a formidable competitor among anode materials for lithium–sulfur (Li-S) batteries; nevertheless, safety issues pose a significant hurdle in its path toward commercial viability. This review enumerates three historical challenges inherent to the Li metal anode: unavoidable volume expansion, multifunctional solid electrolyte interface formation, and uncontrollable lithium dendrite growth. In particular, when paired with a sulfur cathode, the Li anode presents an additional unique hurdle: the shuttle effect. To address these issues, this article offers a thorough examination of the latest innovations aimed at stabilizing the Li metal anode within Li-S batteries. We categorize these approaches into five classifications: liquid electrolyte optimization, enhancement of non-liquid-state electrolytes, Li metal surface modification, Li anode architecture design, and Li alloy improvement. For several noteworthy results within these categories, we have compiled their electrochemical performance into tables, facilitating direct comparison. This detailed analysis illuminates feasible strategies and suggests directions warranting further exploration for optimizing the capability and safety of Li metal anodes in Li-S batteries.