A Self‐Healing Amalgam Interface in Metal Batteries

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.