Facile synthesis of MgCo2O4 nanowires as binder-free flexible anode materials for high-performance Li-ion batteries

MgCo2O4 nanowires are synthesized for the first time through two-step synthesis method, followed by annealing of the MgCo2O4 precursors. The microstructure and morphology of MgCo2O4 nanowires are examined by powder X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. MgCo2O4 nanowires give rise to a BET surface area of 45.1 m2 g−1 and the adsorption average pore size of 11.5 nm. When tested as an anode for lithium-ion batteries, the MgCo2O4 nanowires electrode exhibit exceptional properties in terms of specific capacity, cycling performance, and rate capacity compared with previously reported Co-based binary metal oxides. For instance, when the current densities increase from 5, 10, 15, and 20 A g−1, the discharge capacities of the MgCo2O4 nanowires electrode are about 649, 348, 188, and 121 mAh g−1, respectively. The enhanced electrochemical performance of the MgCo2O4 nanowires can be mainly attributed to the nanostructures which lead to decreased lithium-ion diffusion distances and increased active sites for Li insertion/extraction reactions.