High-capacity sulfur copolymer cathode with metallic fibril-based current collector and conductive capping layer

Abstract

Highly conductive and porous current collectors that can provide favorable interfacial interaction with sulfur components play a critical role in the performance of lithium-sulfur (Li-S) batteries. Although three-dimensional (3D) porous textiles have emerged as promising current collector materials, most reported approaches have reached a limit in producing textiles with metal-like conductivity and do not effectively utilize the large surface area of textiles. Here, we introduce a Li-S copolymer cathode with high areal/specific capacity and good rate capability using a metallic cotton textile (CT)-based current collector that exhibits strong interfacial interaction with sulfur. To fabricate the metallic current collector, CT was first carbonized and subsequently electroplated with nickel (Ni). When a sulfur copolymer-based hybrid slurry and layer-by-layer-assembled conductive capping layer were deposited onto the Ni-electroplated CT, the resulting Li-S copolymer cathode displayed significantly enhanced areal capacity, specific capacity, and rate capability. These improvements were realized due to the full utilization of the large conductive surface area of Ni-electroplated CT as well as the effective chemical confinement of soluble lithium polysulfides by a conductive capping layer. The Li-S copolymer cathode prepared in this study outperforms previously reported sulfur copolymer-based cathodes and provides a basis for the development and design of future high-performance electrodes.