Recent advances in charge mechanism of noble metal-based cathodes for Li-O2 batteries

Lithium-oxygen(Li-O2)batteries are considered as the next generation for energy storages systems due to the higher theoretical energy density than that of Li-ion batteries.However,the high charge over-potential caused by the insulated Li2O2 results in low energy efficiency,side reaction from electrolyte and cathode,and therefore poor battery performance.Designing noble metal-based catalysts can be an effective strategy to develop high-performance Li-O2 batteries with low charge overpotentials and out-standing cycle stability.However,the charge mechanism for noble metal-based catalysts is not clear and even contradictory.Herein,several charge mechanisms of Li2O2 are first discussed.Subsequently,the pos-sible charge processes of Li-O2 batteries with noble metal-based catalysts are illustrated.In addition,the future development for noble metal-based catalysts is outlined.