Implanting MoS₂ quantum dots on MgB₂ nanosheets for lithium–sulfur batteries

Abstract As a new generation of high‐efficiency energy storage devices, lithium–sulfur (Li–S) battery attract increasing attention. However, slow conversion kinetics of lithium polysulfides (LiPSs) and severe shuttle effect are bottlenecks. Developing efficient sulfur host materials to suppress the shuttling of LiPSs and accelerate their conversion kinetics is a general strategy to enhance the performance of Li–S batteries. Herein, MoS₂ quantum dots (QDs)@MgB₂ nanosheet was synthesized using a simple liquid‐phase mixing method. The MoS₂ QDs not only inhibit the stacking of MgB₂ nanosheets but also expose more unsaturated metal active sites, which can effectively improve the adsorption of LiPSs, accelerate its catalytic conversion and suppress its shuttle effect. Moreover, MgB₂ nanosheets can be used as polypropylene (PP) separator modifier. The battery using MoS₂ QDs@MgB₂ as the sulfur host material and MgB₂@PP as the separator has high rate capability and excellent stability. In addition, the discharge‐specific capacity shows a good application prospect.image