Vacancy Engineering for Stable and Fast Li–S Electrochemistry: A Review

Lithium‐sulfur batteries are regarded as strong candidates for the next‐generation high‐energy storage systems due to their exceptionally high theoretical energy density. However, their practical application is hindered by the lithium polysulfide shuttle effect and sluggish sulfur conversion kinetics. Vacancy engineering offers a promising strategy to enhance catalytic performance by tailoring material properties, while comprehensive reviews on its design and mechanisms in Li–S systems remain limited. This review aims to systematically summarize recent advances and discuss vacancy functions in accelerating reactions and guiding future catalyst optimization. We comprehensively summarize the recent progress in utilizing vacancy engineering to enhance the electrochemical kinetics of Li–S batteries. It begins by outlining the core challenges in sulfur chemistry and systematically introduces common strategies for generating various vacancies, such as thermal reduction, chemical etching, plasma treatment, and ion doping. The discussion then focuses on elucidating the critical roles of vacancies (oxygen, sulfur, and metal vacancies, etc.) in anchoring lithium polysulfides and catalyzing their conversion. Finally, this work not only organizes the latest advancements in vacancy engineering for Li–S batteries but also offers valuable insights for defect optimization in other complex electrochemical conversion systems.