Multi‐Phase Heterostructured NiMoN Nanoflower as Bifunctional Separator Coatings for High‐Performance Lithium–Sulfur Batteries

ABSTRACT

Lithium–sulfur (Li–S) batteries are considered promising candidates for next‐generation energy storage owing to their high theoretical energy density and the abundance of sulfur. However, the practical application of Li–S systems is limited by the polysulfide shuttle effect and sluggish redox kinetics. Herein, we report the synthesis and electrochemical evaluation of multi‐phase heterostructured nickel molybdenum nitride (NiMoN) nanoflowers as multifunctional separator coatings for Li‐S batteries. Structural and morphological analyses reveal porous NiMoN nanostructures composed of coexisting Ni, MoN, and Ni _0.2 Mo _0.8 N phases forming abundant heterointerfaces throughout the nanoflower architecture. These interfaces create highly active catalytic sites that promote strong polysulfide adsorption and accelerate their conversion. Electrochemical studies demonstrate that NiMoN significantly reduces charge transfer resistance, enhances Li ⁺ diffusion, and accelerates polysulfide redox reactions compared to NiN and uncoated Celgard separators. While NiN exhibits higher initial specific capacities, the interface‐rich NiMoN heterostructure demonstrates superior cycling stability, and lower capacity fading, maintaining 864.8 mAh g ⁻¹ after 50 cycles at 0.2 C and exhibiting excellent rate performance with strong reversibility at varying C‐rates. These results highlight multi‐phase heterostructured NiMoN nanoflowers as a promising dual‐metal nitride catalyst for suppressing the shuttle effect and enabling high‐performance Li–S batteries.