Strategies for balancing catalytic activity and stability in lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries have great promise for next-generation energy storage devices due to the high theoretical specific capacity (1675 mAh g^-1) of sulfur with chemical conversion for charge storage. However, their practical use is hindered by the slow redox kinetics of sulfur and the “shuttle effect” arising from dissolved lithium polysulfides (LiPSs). In recent years, various carbon-based materials have served as sulfur hosts and catalysts for accelerating sulfur conversion redox kinetics and alleviating LiPS shuttling. However, they often suffer from irreversible passivation and structural changes that destroy their long-term performance. We consider the main problems limiting their stability, including excessive LiPS adsorption, passivation by insulating Li₂S, and surface reconstruction, and clarify how these factors lead to capacity fade. We then outline effective strategies for achieving long-term sulfur catalysis, focusing on functional carbon, such as designing suitable carbon-supported catalyst interfaces, creating well-distributed active sites, adding cocatalysts to improve electron transfer, and using carbon-based protective layers to suppress unwanted side reactions. Using this information should enable the development of stable, high-activity catalysts capable of long-term operation under practical conditions in Li-S batteries.

1. Download: Download high-res image (152KB)
2. Download: Download full-size image