Hierarchical Co3O4 Nanowires as Binder Free Electrodes for Reversible Lithium Storage

Abstract

AbstractTo develop a long cycle life and good rate capability electrode, tricobalt tetraoxide (Co3O4) nanowires with hierarchical structure composed of ultra‐small nanoparticles are directly grown on nickel foam current collector. The size of the nanoparticles is about 10 nm. They are synthesized via a facile hydrothermal route followed by calcination and evaluated as an anode of binder‐free lithium‐ion batteries. The concentration of reactant and duration of reaction are considered as important synthesis parameters. Co3O4 nanowires electrode exhibits excellent electrochemical performance including outstanding cycling performance, a high reversible discharge capacity and good rate capability, owing to the hierarchical architecture composed of micro‐/nanostructures. After rate capacity performance measurements, a capacity of 1060.1 mAh·g−1 is retained. At a rate of 500 mA·g−1, a reversible capacity remains stable as high as 957 mAh·g−1. The enhanced performance is owing to the hierarchical structure of the nanowires and good contact with the substrate which can make electrons efficiently transport from Co3O4 nanowires to the current collectors. The mesoporous structure may facilitate the lithium ion diffusion and mitigate the internal mechanical stress induced by volume variations of the electrode upon cycling, which lead to outstanding electrochemical performance.