In‐situ construction of WN‐Ni ₂ P heterostructures embedded in nitrogen‐doped carbon nanoflakes as lithium sulfide hosts for advanced lithium‐sulfur batteries

Abstract Lithium sulfide (Li 2 S) is widely regarded as the next‐generation cathode material for rechargeable batteries due to its satisfactory theoretical capacity and excellent compatibility with lithium‐free anodes. However, the large‐scale applications of Li 2 S cathodes are limited by the shuttle effect of soluble intermediate lithium polysulfides (LiPSs) and the sluggish redox kinetics of the interconversion between Li 2 S and sulfur (S). Herein, we report novel nitrogen‐doped carbon nanoflakes in‐situ embedded with WN‐Ni 2 P heterostructures (WN‐Ni 2 P@NCN) as a multifunctional host to promote the cycling performance and reaction kinetics of Li 2 S. After loading Li 2 S, the WN‐Ni 2 P@NCN/Li 2 S exhibits stable reversible capacity of 597 mAh g −1 at 0.5 A g −1 over 150 cycles, and superior cycling stability over 800 cycles. The high reversible capacities, excellent cycling properties and superior reaction kinetics of WN‐Ni 2 P@NCN/Li 2 S are attributed to the strong LiPSs fixation, remarkable catalytic activation and high electronic/ionic conductivity of the WN‐Ni 2 P@NCN framework, confirmed by the experiment and the density function theory calculation results. This work offers a new strategy for designing heterostructure nanoflakes with metal nitride and metal phosphide to facilitate the applications of advanced lithium‐sulfur batteries.