Heteroepitaxial growth of ZnO nanosheet bands on ZnCo2O4 submicron rods toward high-performance Li ion battery electrodes

We report the direct synthesis of ZnCo2O4 and ZnO/ZnCo2O4 submicron rod arrays grown on Ni foil current collectors via an ammonia-evaporation-induced method by controlling the ratio of Zn to Co. These three-dimensional (3D) hierarchical self-supported nanostructures are composed of one-dimensional (1D) ZnCo2O4 rods and two-dimensional (2D) ZnO nanosheet bands perpendicular to the axis of the each ZnCo2O4 rod. We carefully deal with the heteroepitaxial growth mechanisms of hexagonal ZnO nanosheets from a crystallographic point of view. Furthermore, we demonstrate the ability of these high-surface-area ZnO/ZnCo2O4 heterostructured rods to enable improved electrolyte permeability and Li ion transfer, thereby enhancing their Li storage capability (similar to 900 mA center dot h center dot g(-1) at a rate of 45 mA center dot h center dot g(-1)) for Li ion battery electrodes.