Status and prospects of polymer electrolytes for solid-state Li-O2 (air) batteries

Li-air batteries have drawn considerable attention due to their high energy density and promising implementation in long-range electric vehicle and wearable electronic devices. Nevertheless, safety concerns, mainly derived from the use of flammable organic liquid electrolytes, have become a major bottleneck to the strategically crucial applications of Li-air batteries. Polymer electrolytes with non-toxicity, low vapor pressure, and non-flammable properties provide a feasible solution to safety issues through the replacement of organic liquid electrolytes, although fundamental understanding of polymer electrolytes for Li-air batteries is still insufficient. Accordingly, substantial research efforts have been devoted to achieving next-generation solid-state Li-air batteries with polymer electrolytes. Herein, we provide a specific review on the development of polymer electrolytes for Li-O-2 (air) batteries, from comprehensive insight to emerging horizons, especially in understanding the underpinning chemistry and electrochemistry that govern the properties of polymer electrolytes for the solid-state lithium-air batteries. The discussion will highlight the recent progress in and challenges associated with polymer electrolytes for Li-O-2 (air) batteries, as well as corresponding strategic perspectives.