Interface Between Solid-State Electrolytes and Li-Metal Anodes: Issues, Materials, and Processing Routes

Li metal, which has a high theoretical capacity and negative electrochemical potential, is regarded as the "holy grail" in Li-ion batteries. However, the flammable nature of liquid electrolyte leads to safety issues. Hence, the cooperation of solid-state electrolyte and Li-metal anode is demanded. However, the short cycle life induced by interfacial issues is the main challenge faced by their cooperation. In this review, dendrite and interfacial side reactions are comprehensively analyzed as the main interfacial problems. Meanwhile, the "state-of-the-art" interphase materials are summarized. The challenges faced by each kind of material are underscored. Moreover, different processing routes to fabricate artificial interphase are also investigated from an engineering perspective. The processing routes suitable for mass production are also underscored.