Integrated ion–electron-conducting interspace for high-performance lithium–sulfur batteries

Developing multifunctional separators is essential for mitigating the polysulfide shuttle effect and unstable lithium deposition in lithium–sulfur (Li–S) batteries. In this work, a series of antiperovskite nitrides was synthesized via a hydrothermal nitridation–reduction method and coated onto polypropylene (PP) separators to fabricate composite membranes. Due to its abundant metallic active sites and high electronic conductivity, the ZnNNi 3 modification enables strong chemisorption and accelerated catalytic conversion of polysulfides. Simultaneously, it provides rapid Li + transport pathways that guide uniform Li plating and effectively suppress dendrite growth. Consequently, Li–S batteries with the ZnNNi 3 @PP separator retain 76.5% capacity after 100 cycles at 0.5 C and deliver 589.9 mAh g −1 at 3 C. At a high sulfur loading of 6.4 mg cm −2 , the ZnNNi 3 @PP achieves 910.5 mAh g −1 at 0.2 C and maintains 80.5% retention over 240 cycles with an ultralow fading rate of 0.08% per cycle. Li‖Li symmetric batteries further exhibit stable cycling for over 2000 h at 0.2 mA cm −2 , confirming that ZnNNi 3 @PP enables uniform lithium deposition. This antiperovskite nitride-based modification strategy represents a promising technical route for advancing high-performance Li–S batteries.