MnCo2O4/MoO2 Nanosheets Grown on Ni foam as Carbon- and Binder-Free Cathode for Lithium-Oxygen Batteries

Carbon is usually used as cathode material for Li-O-2 batteries. However, the discharge product, such as Li2O2 and LiO2, could react with carbon to form an insulating lithium carbonate layer, resulting in cathode passivation and capacity fading. To solve this problem, the development of non-carbon cathodes is highly desirable. Herein, we successfully synthesized MnCo2O4 (MCO) nanoparticles anchored on porous MoO2 nanosheets that are grown on Ni foam (current collector) (MCO/MoO2@Ni), acting as a carbon- and binder-free cathode for Li-O-2 batteries, in an attempt to improve the electrical conductivity, electrocatalytic activity, and durability. This MCO/MoO2@Ni electrode delivers excellent cyclability (more than 400cycles) and rate performance (voltage gap of 0.75V at 5000 mA g(-1)). Notably, the battery with this electrode exhibits a high energy efficiency (higher than 85%). The advanced electrochemical performance of MCO/MoO2@Ni can be attributed to its high electrical conductivity, excellent stability, and outstanding electrocatalytic activity. This work offers a new strategy to fabricate high-performance Li-O-2 batteries with non-carbon cathode materials.