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

Lithium -sulfur (Li-S) 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 Li-S 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.