Ti3C2T MXene cathode catalyst with efficient decomposition Li2O2 and high-rate cycle stability for Li-O2 batteries

MXenes have been theoretical predicted as one of the most promising materials for catalytic cathode materials in Li-O2 batteries (LOBs). Herein, we demonstrated the outstanding electrocatalytic performance of Ti3C2Tx MXene as cathode catalyst for LOBs. The Ti3C2Tx MXene exhibited highly efficient catalytic capability for the formation/decomposition of discharge product, large specific capacity and high-rate cycle stability. The Ti3C2Tx MXene provided a heterogeneous surface condition and dominated the discharge/charge products evolution with multi-formation kinetics of Li2O2 and Li2-xO2 at high-rate conditions. Furthermore, the porous structure of discharge products composed by the vertical growing Li2O2 nanoflakes favored the mass transport between the electrode/electrolyte interfaces. As a consequence, the Ti3C2Tx MXene cathode delivered a large capacity of 15468 mAh g−1 and an excellent high rate cyclability of 155/80 cycles at a high current of 500/1000 mA g−1. This work provides intrinsic insights into designing high-performance MXene based electrocatalysts for LOBs.