Perovskite La_0.5Sr_0.5CoO_3−δ Grown on Ti₃C₂T_x MXene Nanosheets as Bifunctional Efficient Hybrid Catalysts for Li–Oxygen Batteries

Li–oxygen batteries (LOBs) have drawn widespread attention in the past decades. Herein, bifunctional hybrid catalysts based on perovskite La0.5Sr0.5CoO3−δ with Ti3C2Tx MXene nanosheets have been prepared for Li–oxygen batteries as effective catalysts. It is the first time using high Li ionic diffusion Ti3C2Tx in Li–oxygen batteries system and making it, as substrate, in situ increase the high oxygen adsorption and O2– transport perovskite La0.5Sr0.5CoO3−δ. In this way, the hybrid catalysts show outstanding catalytic performance to facilitate the reaction kinetics, which display overpotential of only 0.87 V, lower than the Ti3C2Tx by about 540 mV and La0.5Sr0.5CoO3−δ by about 430 mV. The Li–oxygen batteries with LaSrCoO/Ti3C2Tx electrodes run more than 80 cycles at 500 mA g–1 with capacity restriction of 1000 mAh g–1, much better than Ti3C2Tx (9 cycles), La0.5Sr0.5CoO3−δ (15 cycles), and other reported catalysts based on the perovskite. Moreover, the Li–oxygen batteries with LaSrCoO/Ti3C2Tx electrodes deliver the highest initial discharge capacity of about 11 340 mAh g–1 at 500 mA g–1, which is about twice those of the LaSrCoO cathode (6700 mAh g–1) and Ti3C2Tx (5210 mAh g–1). All the results suggest that the strategy would be a promising approach to enhance the performance of LOBs.