Growth of Ultrathin ZnCo₂O₄ Nanosheets on Reduced Graphene Oxide with Enhanced Lithium Storage Properties

The growth of ultrathin ZnCo₂O₄ nanosheets on reduced graphene oxide (denoted as rGO/ZnCo₂O₄) via a facile low-temperature solution method combined with a subsequent annealing treatment is reported. With the assistance of citrate, interconnected ZnCo₂O₄ nanosheets can assemble into hierarchically porous overlays on both sides of rGO sheets. Such a hybrid nanostructure would effectively faciliate the charge transport and accommodate volume variation upon prolonged charge/discharge cycling for reversible lithium storage. As a result, the rGO/ZnCo₂O₄ nanocomposite manifests a very stable high reversible capacity of around 960 mAh g⁻¹ over 100 cycles at a low current density of 90 mA g⁻¹ and excellent rate capability.