A reversible long-life lithium-air battery in ambient air

Electrolyte degradation, Li dendrite formation and parasitic reactions with H2O and CO2 are all directly correlated to reversibility and cycleability of Li-air batteries when operated in ambient air. Here we replace easily decomposable liquid electrolytes with a solid Li-ion conductor, which acts as both a catholyte and a Li protector. Meanwhile, the conventional solid air cathodes are replaced with a gel cathode, which contacts directly with the solid catholyte to form a closed and sustainable gel/solid interface. The proposed Li-air cell has sustained repeated cycling in ambient air for 100 cycles (similar to 78 days), with discharge capacity of 2,000 mAhg(-1). The recharging is based largely on the reversible reactions of Li2CO3 product, originating from the initial discharge product of Li2O2 instead of electrolyte degradation. Our results demonstrate that a reversible long-life Li-air battery is attainable by coordinated approaches towards the focal issues of electrolytes and Li metal.