Flower-like ZnCo2O4 nanowires: toward a high-performance anode material for Li-ion batteries

Abstract

Rising interest in lightweight, thin, and flexible energy storage devices has led to numerous studies that aim to fulfill the special needs of next-generation, high-performance flexible electronics. In this study, flower-like ZnCo2O4 nanowires are fabricated by a facile hydrothermal method followed by heat treatment in air at 400 °C. The structures and morphologies of as-prepared ZnCo2O4 nanowires are characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The data indicate that the as-synthesized flower-like ZnCo2O4 nanowires are approximately 2.5 μm in length and range from 50 nm to 150 nm in diameter. The as-prepared flower-like ZnCo2O4 nanowire products are evaluated as anode materials for lithium-ion battery application. The special structural features of ZnCo2O4 nanowires, including high coating uniformity, high coating density, and porous architecture, exert a significant effect on the electrochemical performance of the nanowires. The discharge capacity of ZnCo2O4 flower-like nanowires can reach first discharge capacity at 1430 mA h g−1 to ∼900 mA h g−1 after 50 discharge–charge cycles at a current density of 200 mA g−1, indicating its potential applications for next-generation, high-performance flexible electronics. High battery performance is mainly attributed to the dense and porous nanowire structures composed of interconnected ZnCo2O4 nanoparticles, which provide good electrolyte diffusion and large electrode–electrolyte contact area while reducing volume change during the charge–discharge process. The fabricated electrode can be used to light up commercial light emitting diodes.