Oxygen-permeable and moisture-proof membrane for stable Li-O2/air batteries in humid working environment

The deleterious shuttle of H2O in humid atmosphere causes fatal/irreversible Li-metal anode corrosion and continuous destruction of solid electrolyte interface (SEI) at the Li/electrolyte interface as well as cathode discharge product varies in Lithium-Oxygen/Air batteries (LOBs/LABs), which critically limits their electrochemical performance of LOBs/LABs. Herein, we employ a scalable/flexible [email protected] ([email protected]) membrane with excellent oxygen-permeability and moisture-proofing capability to effectively shield Li anode and entire battery systems from H2O corrosion. The stable dual phobicity of [email protected] membrane is evidenced by contact angle and penetration experiments, and its ability to block H2O crossover is demonstrated via spectroscopy characterizations of the SEI layer in cycled Li-metal surface. The success of the [email protected] membrane has been illustrated by the significantly enhanced cyclability of the Li-metal anodes, depth of full-discharge and cyclability of the LOBs/LABs operated in a humid O2 and practical ambient air atmosphere (RH: 70%). Cycled at limited capacity of 500 mAh/g, the cycle performance of LOBs assembled with [email protected] membranes is five times that of that without [email protected] membranes. This work reveals how the crossover of H2O damages the Li-metal anode (SEI structure/components) and entire LOBs/LABs, and offers a practically effective approach to improve battery operation stability in humid atmosphere.