A Li-Air Battery with Ultralong Cycle Life in Ambient Air

The Li-air battery represents a promising power candidate for future electronics due to its extremely high energy density. However, the use of Li-air batteries is largely limited by their poor cyclability in ambient air. Herein, Li-air batteries with ultralong 610 cycles in ambient air are created by combination of low-density polyethylene film that prevents water erosion and gel electrolyte that contains a redox mediator of LiI. The low-density polyethylene film can restrain the side reactions of the discharge product of Li₂ O₂ to Li₂ CO₃ in ambient air, while the LiI can facilitate the electrochemical decomposition of Li₂ O₂ during charging, which improves the reversibility of the Li-air battery. All the components of the Li-air battery are flexible, which is particularly desirable for portable and wearable electronic devices.