Morphology Engineering of Co3O4 Nanoarrays as Free-Standing Catalysts for Lithium-Oxygen Batteries

The effective shape-controlled synthesis of Co3O4. nanoarrays on nickel foam substrates has been achieved through a simple hydrothermal strategy; When they served as, the binder and conductive-agent-free porous cathodes for nonaqueous Li-O-2 batteries, they sufficiently reflect the favorable catalytic characteristic of Co3O4 and alleviate the problems of serious pore blocking and surface passivation caused;by insoluble and insulating discharge products. In,particular, Co3O4 rectangular nanosheets-exhibit superior electrocatalytic performance comparing with Co3O4, nano wires and hexagonal nanosheets, leading to higher specific capacity and better cycling stability over 54 cycles at 100 mA g(-1), which relate to their good pore structure, large specific surface area, and highly active {112} exposed plane, effectively promoting the-mass transport and reversible formation and-decomposition of discharge products in the cathode. These comparisons further indicate the morphology effect, of nanostructured Co3O4 on their performances as free-standing catalysts for Li-O-2 batteries, which also have been proved through the further analysis of discharge products on different shapes of Co3O4 nanoarrays electrodes.