Hollow and Hierarchical CuCo-LDH Nanocatalyst for Boosting Sulfur Electrochemistry in Li-S Batteries

Lithium-sulfur batteries (LSBs) are promising candidates for next-generation high-efficiency energy storage, yet their practical implementation is seriously impeded by the parasitic shuttle effect and sluggish reaction kinetics. Herein, we develop a unique Cu, Co layered double hydroxide (CuCo-LDH) with a hollow and hierarchical structure as an advanced electrocatalyst to tackle these challenges. Combining the compositional, architectural, and chemical advantages, the as-developed CuCo-LDH enables facile charge transfer, fully exposed active interfaces, and strong interactions with polysulfides via metal-sulfur bonding. When employed in the functional separator, a reliable polysulfide barrier can be established against the shuttling behavior, while the excellent catalytic activity realizes fast and efficient sulfur electrochemistry. As a result, the CuCo-LDH-based LSBs achieve a well-restrained capacity decay of 0.049% per cycle over 500 cycles together with a good rate capability up to 5 C. Moreover, a favorable areal capacity of 4.39 mAh cm-2 and decent cyclability are still attainable even under a high sulfur loading of 4.2 mg cm-2 and a low E/S ratio of 6 ml g-1. This work affords a feasible and instructive pathway toward advanced sulfur electrocatalysts as well as high-performance LSBs.