Flexible Lithium–Air Battery in Ambient Air with an In Situ Formed Gel Electrolyte

Abstract Flexible Li‐air batteries (LABs) have been considered as promising power sources for wearable electronics owing to its higher energy density. However, when operated in ambient air, problems arise, such as Li anode passivation, poor cycle life as well as leakage of liquid electrolyte. Herein, we present a LAB with a tetraethylene glycol dimethyl ether (TEGDME, G4) gel electrolyte, in which the gel is formed in situ through a cross‐linking reaction between the liquid G4 and the lithium ethylenediamine (LiEDA) grown on the surface of Li anode. We demonstrate that the gel can efficiently alleviate the corrosion of the Li anode, and thus the LAB shows a cycle performance over 1175 hours (humidity: 10 % to 40 %), which is much superior to previous reports. Furthermore, the in situ formed gel enhances the electrode/electrolyte interfacial contact, which thus enables the cable‐type LAB to exhibit a great flexibility.