Research Progress of Structural Optimization of Lithium-Sulfur Battery Cathode Materials for Suppressing the Polysulfide Shuttle Effect

Since lithium-sulfur (Li-S) batteries are inexpensive, environmentally friendly, and have an extraordinary theoretical energy density (2600 Wh/kg), they have emerged as viable candidates for future energy storage systems. However, the polysulfide shuttle effect leads to the loss of active material, capacity degradation, and reduced cycle stability which severely hindering their practical application. This review elaborates on the working principles of lithium-sulfur batteries, analyzes mechanisms behind the shuttle effect and its impact on battery performance, and summarizes recent strategies for optimizing cathode materials including nano-modification (e.g., Co-PB@S and Fe3C/PB@S cathode materials), polymer modification (e.g., PEDOT-S@PAN nanofiber structures) and composite modification (e.g., multifunctional MXene/CNT-1Zr and Ti3C2/S@PDA composites). These materials effectively suppress polysulfide migration through physical confinement, chemical adsorption, and catalytic conversion mechanisms, thereby improving sulfur utilization and cycling stability. Finally, this review emphasizes that upcoming studies should prioritize evaluating performance in practical scenarios, including minimal electrolyte amounts and high sulfur loading, to advance the practical application of Li-S batteries. The findings provide theoretical insights and technical prospects for improving Li-S batteries.