Synthesis and application of single-atom catalysts in sulfur cathode for high-performance lithium–sulfur batteries

Lithium–sulfur (Li-S) batteries are regarded as one of the most promising energy storage devices because of their low cost, high energy density, and environmental friendliness. However, Li-S batteries suffer from sluggish reaction kinetics and serious “shuttle effect” of lithium polysulfides (LiPSs), which causes rapid decay of battery capacity and prevent their practical application. To address these problems, introducing single-atom catalysts (SACs) is an effective method to improve the electrochemical performance of Li-S batteries, due to their high catalytic efficiency and definite active sites for LiPSs. In this paper, we summarized the latest developments in enhancing the electrochemical performance of cathode for Li-S batteries through introducing different SACs. Furthermore, we briefly introduced the catalytic mechanism of SACs and discussed the strategies of synthesizing SACs, including the spatial confinement strategy and the coordination design strategy. Finally, the challenges and prospects in this field are proposed. We believe that this review would help to design and fabricate high-performance Li-S batteries via introducing SACs and boost their practical application.