Organic-inorganic composite artificial SEI layer for Improved Electrochemical Performance of Lithium Metal Anodes

Abstract

Lithium metal has garnered significant attention as an anode material due to its high theoretical capacity (3,860 mAh g-1), low redox potential (-3.04 V vs. the standard hydrogen electrode) as well as the lowest density (0.53 g cm-3 However, its practical application remains limited by critical challenges, including high chemical reactivity, substantial volume changes during cycling, unstable solid electrolyte interphase (SEI), dendrite growth, and the formation of inactive "dead" lithium during the plating/stripping process. To advance the commercialization of lithium metal anodes, the development of a stable and conformal artificial SEI layer is crucial to achieve uniform lithium deposition and reliable cycling performance. To address these issues, polymer-based SEI layers have been extensively studied due to their chemical stability, mechanical flexibility, and cost-effectiveness. Nonetheless, their inherently low ionic conductivity and mechanical strength necessitate further improvement. The integration of inorganic nanofillers into polymer matrices has emerged as a promising strategy to enhance both ionic conductivity and mechanical robustness. This composite SEI layer not only provides a strong physical barrier but also optimizes the chemical and electrical interactions with lithium ions, facilitating efficient ion transport. In this study, we investigate the effects of organic-inorganic composite artificial SEI layers on mitigating dendrite formation and improving lithium electrodeposition behavior. The influence of polymeric SEI layers on lithium electrodeposition is systematically analyzed, and comprehensive electrochemical performance results are presented to validate the approach.