Synergistic Catalysis by Heterostructures Constructed with Transition Metals for Lithium–Sulfur Batteries

Lithium–sulfur batteries (LSBs) show great potential as next-generation energy storage systems due to their high energy density. However, their practical application is hindered by the slow conversion of lithium polysulfides (LiPSs) and the resulting severe shuttle effect. Catalysis has emerged as a promising solution to address these challenges, but a single catalyst often falls short of meeting all of the requirements for efficient LiPS conversion. This review highlights synergistic catalytic strategies employing metal-based heterostructures with engineered interfaces between distinct materials having complementary properties, including metal/metal compound-based heterostructures, metal-doped metal-compound-based heterostructures, and single-atom heterostructures. These catalysts exhibit exceptional performance by accelerating LiPS conversion to enhance sulfur utilization and enable long-cycling stability. The methods with advanced characterization techniques and theoretical approaches to understand the functions of heterostructures are also discussed, offering insights into catalyst design and optimization. This review provides perspectives and future directions to advance LSB commercialization through catalyst development.