Nitrogen and sulfur co-doped MXene@FeCoNiP as an efficient catalyst for enhanced lithium-sulfur batteries

Abstract

Lithium-sulfur (Li–S) batteries have been regarded as be one of the most promising energy storage systems on account of its high theoretical energy and power density. Nevertheless, it is limited by the severe shuttle effect of lithium polysulfides (LiPS) and retarded sulfur reaction kinetics. Herein, a thermal migration route was used to design nitrogen/sulfur co-doped MXene@FeCoNiP (N,S-MXene@FeCoNiP) composites as a promising catalyst for Li–S batteries. The prepared N,S-MXene@FeCoNiP possessing three-dimensional framework can promote rapid electron/ion transfer during battery cycling. The nitrogen/sulfur co-doping could not only improve electronic conductivity, but also provide more catalytic sites. Moreover, the synergy of highly polar MXene and FeCoNiP as well as N/S co-doping can hinder the shuttling of polysulfides and facilitate the LiPS conversion. Benefiting from these advantages, N,S-MXene@FeCoNiP–S cathode showed high specific capacity, remarkable rate capability and good cycling stability. This work is expected to provide inspiration for the reasonable design of catalysts toward advanced Li–S batteries.