Multi-functional W,N-co-doped nanoporous carbon contributes to high-performance Li-S batteries

Li-S batteries (LSBs), with their exceptional theoretical energy density, are widely recognized as a leading option for future energy storage solutions. Nevertheless, on the way to commercialization, the poor conductivity of the positive electrode, the easy dissolution loss of the active substance, and the serious dendrite growth of the negative electrode are stumbling blocks. Therefore, this work designs a novel tungsten and nitrogen-co-doped nanoporous carbon (W,N-C) with multifunction: chemically adsorbs the polysulfides to inhibit shuttling behavior, accelerates Li + transfer, and catalyzes polysulfides redox to address the aforementioned issues of LSBs. As expected at the beginning of the design, the prepared W,N-C-5/S composites cathodes demonstrate excellent performances, i.e., delivering an initial capacity of 944.9 mAh g −1 and a reversible capacity of 771.7 mAh g −1 after 500 cycles at 1 ​C, significantly outperforming the N-C/S contrast sample. The proposed method offers a feasible solution for boosting the electrochemical performance of LSBs. In this work, a multifunctional W, N co-doped porous carbon (W,N-C) was successfully synthesized using tungsten salt and ramie degumming waste, and used as a sulfur host to accelerate the redox of LiPSs and inhibit the shuttle of LiPSs. The prepared W,N-C-5/S composite cathode can maintain a high reversible capacity of 771.7 mAh g −1 after 500 cycles at a high discharge rate of 1.0C.