Electrochemical active interlayer with porous architecture for reliable lithium–sulfur batteries

Although lithium–sulfur batteries have excellent theoretical specific capacity (1675 mAh g−1) and high energy density (2600 wh kg−1), their practical application is hampered by the severe "shuttle effect" of polysulfides in ether-based electrolytes. Soluble polysulfides can migrate across separator and react with lithium metal, resulting in the rapid capacity decay. In this study, we proposed an electrochemical active porous architecture (EPA) interlayer to address the tricky issue. Firstly, the porous architecture guarantees efficient electrolyte diffusion. Additionally, the catalytic vanadium nitride particles within the conductive skeleton can capture soluble polysulfides, accelerate their redox reaction, and suppress the "shuttle effect", thereby further restraining the parasitic reaction between the lithium metal anode and polysulfides. Therefore, integrating the EPA interlayer in the battery enables an initial capability of 1465.8 mAh g−1 at 0.1C and delivers a good rate performance at 2.0C (668.0 mAh g−1). The battery achieves an average capacity of 796.7 mAh g−1 within the 500cycles under 0.5C, with a high average Coulombic efficiency of 99.8 %, indicating the practical potential of EPA interlayer design for application in reliable lithium–sulfur batteries.