Recent Progress in Cathode Side for Lithium-Sulfur Batteries to Mitigate the Shuttle Effect

The great potential theoretical specific capacity (1675 mAh g-1) and the energy density (2600 Wh kg-1) of sulfur combined with the costeffectiveness and environmental sustainability of this substance have catapulted lithium-sulfur (Li-S) batteries to become a leader in future energy storage. Irrespective of these merits, a ubiquitous “shuttle effect” caused by lithium polysulfides (LiPS x) is still a tough obstacle to commercialization that induces rapid capacity decay and reduced Coulombic efficiency. This is a review of the Li-S electrochemical environment with special focus on the mechanistic bases of polysulfide shuttling. On the migration of the shuttle effect, this review paper has given the summation of the existing modification directions with emphasis on the modification strategies of cathodes and three discrete illustrations namely modification of carbonbased composite material, modification of transition metal catalyst, and modification of polymeric sulfur structure. Moreover, the chemical anchoring of the redox rate, physical sequestration, is broken down into the interplay between the two and synergistic strategies are revealed. The review ends with the determination of the long-term technical bottlenecks and the description of future directions of the achievement of high-performance and practical Li-S systems.