Free-standing ZIF-8 derived nitrogen and sulfur co-doped porous carbon nanofibers host for high mass loading lithium-sulfur battery

Abstract

Lithium–sulfur batteries are promising next-generation energy storage device, but polysulfide shuttling which results in the capacity decay, still remains a great challenge. In this work, we proposed a sulfur and nitrogen co-doped strategy to increase interaction between the lithium sulfides and host. Herein, free-standing S and N dually doped porous carbon nanofibers (donated as SN-PCNF) are prepared and serve as efficient sulfur host materials. Benefitting from the S and N co-doped strategy, the chemical adsorption of lithium polysulfides increases, thus the free-standing SN-PCNF@S cathode delivers an initial discharge capacity of 1133 mA h·g−1 with 80% sulfur loading. Furthermore, the DFT calculations reveals the stronger polysulfide binding with nitrogen and sulfur co-doped carbons than that with nodoped or nitrogen single-doped carbons.