NiS2-MoS2@MXene heterostructures for enhancing polysulfide adsorption and conversion of Li S battery

Lithium‑sulfur (LiS) batteries attract great interests due to their low cost and high energy density. However, the slow electrochemical reaction and shuttle effect hinder the commercial applications of LiS batteries. Herein, NMM (NiS2-MoS2@MXene) heterostructures containing a large number of defects were successfully prepared to provide more active sites for polysulfide catalysis and adsorption. The resulted battery exhibited exceptional electrochemical performance with the use of 20 wt% (NMM-20) conductive agent MXene. The battery assembled with NMM-20 has an excellent reversible capacity of 767.3 mAh g−1 after 800 cycles at 0.5C and the NMM-20 also showed excellent rate performance. Importantly, a favorable areal capacity of 5 mAh cm−2 was obtained under a high sulfur load of 7 mg cm−2. This work extends the preparation of heterogeneous materials and provides insight into the optimal addition amounts of conductive agents in heterostructures.