A Bifunctional Fibrous Scaffold Implanted with Amorphous Co2P as both Cathodic and Anodic Stabilizer for High-Performance Li─S Batteries.

Abstract

The shuttling of lithium polysulfides (LiPSs) and the formation of lithium dendrites have substantially impeded the practical application of lithium-sulfur (Li─S) batteries. To simultaneously solve these issues, a porous carbon fibrous scaffold embedded with amorphous Co₂P (A─Co₂P) is designed as both a cathodic and anodic stabilizer to construct high-rate and long-life Li─S batteries. The meticulously designed self-supporting membrane with an integrated carbon network and porous structure offers superior conductivity and copious spaces for uniform Li₂S precipitation in the cathode and Li deposition in the anode. Moreover, the incorporated A─Co₂P provides abundant unsaturated sites, which can not only facilitate the exposure of active sites but also modulate the electronic configuration for enhanced LiPSs adsorption and catalysis capability. Concurrently, the presence of lithiophilic A─Co₂P sites also reinforces the stability of Li anode with the suppressed formation of dendrites. The constructed full Li─S batteries deliver a high areal capacity of 6.6 mAh cm^-2 with a sulfur loading of 8.5 mg cm^-2 and a low capacity decay rate of 0.047% per cycle after 800 cycles. This work provides a simple yet effective strategy to construct practical Li─S batteries by simultaneously addressing LiPSs shuttling and Li dendrite growth.