Artificial SEI Transplantation – A Pathway to Enabling Lithium Metal Cycling in Water Containing Electrolytes

The activity of metallic anodes, such as Li, in water containing electrolytes is essential for the development and realization of high energy-density battery systems like Li-air. Due to the inherent incompatibility between Li and water, pathways must be established to allow these two materials to coexist in a battery system. In this work, the formation and transplantation of water protective SEIs on the surface of Li metal using ionic liquid electrolytes, allowed for the cycling of Li metal in water containing organic electrolytes. Further, we found that these SEIs could be utilized to successfully cycle Li from air-containing organic electrolytes as well. This discovery opens an avenue of research wherein Li metal anodes find a practical use in Li-air batteries, allowing further development of a battery system capable of delivering the highest theoretical specific energy among rechargeable battery systems.