A Self‐Healing Amalgam Interface in Metal Batteries

Abstract Poor cyclability and safety concerns caused by the uncontrollable dendrite growth and large interfacial resistance severely restrict the practical applications of metal batteries. Herein, a facile, universal strategy to fabricate ceramic and glass phase compatible, and self‐healing metal anodes is proposed. Various amalgam‐metal anodes (Li, Na, Zn, Al, and Mg) show a long cycle life in symmetric cells. It has been found that liquid Li amalgam shows a complete wetting with the surface of lanthanum lithium titanate electrolyte and a glass‐phase solid‐state electrolyte. The interfacial compatibility between the lithium metal anode and solid‐state electrolyte is dramatically improved by using an in situ regenerated amalgam interface with high electron/ion dual‐conductivity, obviously decreasing the anode/electrolyte interfacial impedance. The lithium‐amalgam interface between the metal anode and electrolyte undergoes a reversible isothermal phase transition between solid and liquid during the cycling process at room temperature, resulting in a self‐healing surface of metal anodes.