In‐situ construction of WN‐Ni <sub>2</sub> P heterostructures embedded in nitrogen‐doped carbon nanoflakes as lithium sulfide hosts for advanced lithium‐sulfur batteries
Sheng Liang, Zihao Chen, Kunhong Hu, Xin Liang, Lei Hu, Ningning Zhou, Li‐Li Wang, Lingli Liu, Xin‐Kai Ding, Hongge Pan, Bin Chen, Chu Liang
Abstract
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.