Facile synthesis of partially oxidized Mn₃O₄-functionalized carbon cathodes for rechargeable Li-O₂ batteries

High charging overpotential (low energy efficiency) is one of the most important challenges preventing the use of current nonaqueous Li-O₂ batteries. This study demonstrates direct in situ-incorporation of metal oxides on carbon during synthesis and the associated application to nonaqueous Li-O₂ battery catalysts. The partially oxidized Mn₃O₄ (Mn₃O₄/Mn₅O₈)-incorporating carbon cathode shows an average overpotential reduction of ∼8% charge/discharge during 40 cycles in a rechargeable nonaqueous Li-O₂ cell. Here, we suggested the possibility that only a small amount of the oxide species (<5%) could show catalytic effects during charge in a rechargeable Li-O₂ cell.