Stable Lithium Anode of Li-O₂ Batteries in a Wet Electrolyte Enabled by a High-Current Treatment

Rechargeable Li-air (O₂) batteries have attracted a great deal of attention because of their high theoretical energy density and been regarded as a promising next-generation energy storage technology. Among numerous obstacles to Li-air (O₂) batteries preventing their use in practical applications, water is a representative impurity for Li-air (O₂), which could hasten the deterioration of the anode and accelarate the premature death of cells. Here, we report an effective in situ high-current pretreatment process to enhance the cycling performance of Li-O₂ batteries in a wet tetraethylene glycol dimethyl ether-based electrolyte. With the help of certain levels of H₂O (from 100 to 2000 ppm) in the electrolyte, adequate Li₂O formed on the lithium anode surface after high-current pretreatment, which is necessary for a robust and uniform solid electrolyte interphase layer to protect Li metal during the long-term discharge-charge cycling process. This in situ high-current pretreatment method in a wet electrolyte is shown to be an effective approach for enhancing the cycling performance of Li-O₂ batteries with a stable Li metal anode and promoting the realization of practical Li-air batteries.