Recent progress and strategies of cathodes toward polysulfides shuttle restriction for lithium-sulfur batteries

Lithium-sulfur batteries (LSBs) have already developed into one of the most promising new-generation high-energy density electrochemical energy storage systems with outstanding features including high-energy density, low cost, and environmental friendliness. However, the development and commercialization path of LSBs still presents significant limitations and challenges, particularly the notorious shuttle effect triggered by soluble long-chain lithium polysulfides (LiPSs), which inevitably leads to low utilization of cathode active sulfur and high battery capacity degradation, short cycle life, etc. Substantial research efforts have been conducted to develop various sulfur host materials capable of effectively restricting the shuttle effect. This review firstly introduces the fundamental electrochemical aspects of LSBs, followed by a comprehensive analysis of the mechanism underlying the shuttle effect in Li–S batteries and its profound influence on various battery components as well as the overall battery performance. Subsequently, recent advances and strategies are systematically reviewed, including physical confinement, chemisorption, and catalytic conversion of sulfur hosts for restricting LiPSs shuttle effects. The interplay mechanisms of sulfur hosts and LiPSs are discussed in detail and the structural advantages of different host materials are highlighted. Furthermore, key insights for the rational design of advanced host materials for LSBs are provided, and the upcoming challenges and the prospects for sulfur host materials in lithium-sulfur batteries are also explored. Graphical abstract: (Figure presented.)