Bio-inspired, sustainable intermolecular network for enhanced longevity in lithium-sulfur batteries

Lithium-sulfur batteries (LiSBs) are a promising candidate for next-generation energy storage systems owing to their high theoretical capacity and cost efficiency, and their potential applicability in the aerospace field is being increasingly investigated. However, severe polysulfide (LiPS) shuttling and various side reactions involving LiPS shuttles prevent the practical application of LiSBs. Despite significant advancements, various practical factors, such as energy density, ease of manufacture, eco-friendliness, and improved cycling behavior, continue to present challenges. In this study, a bioinspired, sustainable intermolecular network is designed for extending the lifetime of LiSBs. The network consists of a three-dimensional crosslinking by various intermolecular forces between eco-friendly chitosan and tannic acid inspired by 3,4-dihydroxy-phenylalanine(DOPA)-Lysine interaction in marine mussels, which is applied as a polymer binder that significantly suppresses the LiPS shuttle and improves the structural, chemical, and electrochemical properties of sulfur cathodes. The developed LiSB with this binder demonstrated a highly stable cycling performance over 2000 cycles, showing 0.015 % capacity decay per cycle at a high rate of 2 C. This study provides a viable strategy for designing eco-friendly binders that extend the lifespan of LiSBs, contributing toward their practical application.