Fundamental Understanding and Construction of Solid-State Li-Air Batteries.

Nonaqueous Li-air batteries with ultrahigh theoretical energy density have attracted much attention in the development of clean energy technology. However, a series of safety challenges including the flammable, volatile organic liquid electrolyte, together with the electrolyte decomposition have greatly hindered their practical development. Solid-state electrolytes with superior mechanical strength, good chemical stability under open-air system, wide electrochemical window, nonflammable properties provide a feasible strategy to overcome the safety issues and achieve a stable, applicable Li-air battery system. In this article, a comprehensive review of solid-state Li-air batteries is provided. Based on the overall understanding of the necessity of developing a solid-state Li-air battery and ion migration mechanism in solid electrolytes, the construction strategies of solid-state Li-air battery including cathode fabrication, Li anode optimization, electrolyte design, and the interface regulation between electrodes and electrolyte are presented. The prospects of solid-state Li-air batteries are also proposed at the end. It is expected that this review would provide a systematic understanding and theoretical guidance in designing and developing safe, stable, applicable solid-state Li-air batteries.