Electrocatalyzing S Cathodes via Multisulfiphilic Sites for Superior Room-Temperature Sodium-Sulfur Batteries
Room-temperature sodium-sulfur (RT-Na/S) batteries hold great promise for sustainable and cost-effective applications. Nevertheless, it remains a great challenge to achieve high capacity and cycling stability due to the low activity of sulfur and the sluggish conversion kinetics between polysulfide intermediates and sodium sulfide. Herein, an electrocatalyzing S cathode is fabricated, which consists of porous core-shell structure and multisulfiphilic sites. The flexible carbon structure effectively buffers volume changes during cycling and provides enclosed spaces to store S8 with exceptional conductivity. Significantly, the multisulfiphilic sites (ZnS and CoS2) enhance catalysis toward multistep S conversion, which effectively suppresses long-chain polysulfides dissolution and improves the kinetics of short-chain polysulfides. Thus, the obtained S cathodes achieve an enhanced cycling performance (570 mAh g-1 at 0.2 A g-1 over 1000 cycles), decent rate capability (250 mAh g-1 at 1.0 A g-1 over 2000 cycles), and high energy density of 384 Wh kg-1 toward practical applications.