Interface Engineering Toward Expedited Li S Deposition in Lithium-Sulfur Batteries: A Critical Review.

Lithium-sulfur batteries (LSBs) with superior energy density are among the most promising candidates of next-generation energy storage techniques. As the key step contributing to 75% of the overall capacity, Li S deposition remains a formidable challenge for LSBs applications because of its sluggish kinetics. The severe kinetic issue originates from the huge interfacial impedances, indicative of the interface-dominated nature of Li S deposition. Accordingly, increasing efforts have been devoted to interface engineering for efficient Li S deposition, which has attained inspiring success to date. However, a systematic overview and in-depth understanding of this critical field are still absent. In this review, the principles of interface-controlled Li S precipitation are presented, clarifying the pivotal roles of electrolyte-substrate and electrolyte-Li S interfaces in regulating Li S depositing behavior. For the optimization of the electrolyte-substrate interface, efforts on the design of substrates including metal compounds, functionalized carbons, and organic compounds are systematically summarized. Regarding the regulation of electrolyte-Li S interface, the progress of applying polysulfides catholytes, redox mediators, and high-donicity/polarity electrolytes is overviewed in detail. Finally, the challenges and possible solutions aiming at optimizing Li S deposition are given for further development of practical LSBs. This review would inspire more insightful works and, more importantly, may enlighten other electrochemical areas concerning heterogeneous deposition processes.