N/P Codoped Carbon Nanofibers Coupled with Chrysanthemum-Like Cobalt Phosphide Hybrid for Stable Lithium–Sulfur Batteries

Lithium–sulfur batteries demonstrate enormous energy density and are promising forms of energy storage. Unfortunately, the slow redox kinetics and polysulfide shuttle effect are some of the factors that prevent its development. To address these issues, the combination of nitrogen/phosphorus codoped carbon nanofiber membrane with chrysanthemum-like cobalt phosphide hybrid (CoP@NP-CF) and utilized Li2S6 catholyte for lithium–sulfur battery. The conductive NP-CF facilitates fast electronic/ionic transport and chemisorption of lithium polysulfides, while the chrysanthemum-like CoP has a strong affinity for lithium polysulfides, effectively anchoring them, facilitating the redox conversion of polysulfide species, and effectively diminishing reaction barriers. The cell with CoP@NP-CF delivers the first discharge capacity of 1211.8 mAh g–1 and maintains 928.5 mAh g–1 after 300 cycles (0.2C) at a sulfur loading of 5.2 mg. In addition, its initial discharge capacity can remain at 8.6 mAh even at 10.5 mg for a duration of 100 cycles. This research indicates the potential application of CoP@NP-CF hybrid materials in lithium–sulfur (Li–S) batteries.