Artificial solid electrolyte interphase: The Holy Grail for Li-S batteries

Lithium metal exhibits exceptional characteristics, owing to its highest specific capacity (3860 mAh g−1) and the lowest electrochemical potential (−3.04 V vs. SHE) among all available metal anodes. The synergy effect of Li and sulfur, with specific capacity of 1670 mAh g−1, positions Li–S batteries (LSBs) as a highly promising candidate for the next generation of high-energy density batteries. Nonetheless, the full commercialization of LSBs is dependent upon overcoming a range of shortcomings that such batteries possess. One of the most formidable challenges is the pervasive issue of Li dendrite nucleation and growth on the anode surface, caused by the instability of the solid electrolyte interphase layer. Numerous efforts have been made so far to control the nucleation and growth of Li dendrites, with the establishment of a stable artificial solid electrolyte interphase (ASEI) layer proving to be one of the most effective approaches. This review provides a focused, comprehensive analysis of ASEI layers, addressing a critical gap in existing literature, which often broadly covers Li anode challenges without specifically targeting ASEI-related strategies. It explores recent advancements in ASEI fabrication methods, including dip coating, drop casting, roll pressing, magnetron sputtering, and other innovative techniques, with a thorough discussion of each method's strengths, limitations, and key influencing factors. Furthermore, the review examines the scalability, performance, and effectiveness of ASEI layers under real-world conditions, such as high sulfur loading, limited electrolyte volumes, and carbonate-based electrolytes, while assessing their impact on electrochemical performance across varied battery configurations.