Interfacial Layers with Desolvation Function Induced Stable Deposition of Lithium Metal for Long-Cycling Lithium...

The unstable solid electrolyte interface (SEI) formed by uncontrollable electrolyte degradation, which leads to dendrite growth and Coulombic efficiency decay, hinders the development of Li metal anodes. A controllable desolvation process is essential for the formation of stable SEI and improved lithium metal deposition behavior. Here, we show a functional artificial interface protective layer comprised of chondroitin sulfate-reduced graphene oxide (CrG), on which polar functional groups are distributed to effectively reduce the energy barrier for desolvation of Li⁺ and effectively alienate solvent molecules to avoid solvent involvement in SEI formation, thus promoting the formation of a LiF-rich SEI. Consequently, stable Coulombic efficiencies of 98.4% were achieved after 500 cycles in a Li//Cu cell. Moreover, the LiFePO₄ full cells achieve steady circulation (470 cycles at 80%, 1 C) with a negative/positive electrode capacity ratio of 2.87. Our multifunctional artificial interface protective layer provides a new way to advance Li metal batteries.