Stable Lithium\nAnode of Li–O2 Batteries\nin a Wet Electrolyte Enabled by a High-Current Treatment

Rechargeable Li–air (O2) batteries\nhave attracted\na great deal of attention because of their high theoretical energy\ndensity and been regarded as a promising next-generation energy storage\ntechnology. Among numerous obstacles to Li–air (O2) batteries preventing their use in practical applications, water\nis a representative impurity for Li–air (O2), which\ncould hasten the deterioration of the anode and accelarate the premature\ndeath of cells. Here, we report an effective in situ high-current\npretreatment process to enhance the cycling performance of Li–O2 batteries in a wet tetraethylene glycol dimethyl ether-based\nelectrolyte. With the help of certain levels of H2O (from\n100 to 2000 ppm) in the electrolyte, adequate Li2O formed\non the lithium anode surface after high-current pretreatment, which\nis necessary for a robust and uniform solid electrolyte interphase\nlayer to protect Li metal during the long-term discharge–charge\ncycling process. This in situ high-current pretreatment method in\na wet electrolyte is shown to be an effective approach for enhancing\nthe cycling performance of Li–O2 batteries with\na stable Li metal anode and promoting the realization of practical\nLi–air batteries.