NiO nanorod array anchored Ni foam as a binder-free anode for high-rate lithium ion batteries†
Here we report the preparation of 3D binder-free NiO nanorod-anchored Ni foam electrodes, and their application as anode materials for rechargeable lithium-ion batteries. By anodization followed by thermal annealing, blooming flower-like NiO arrays were anchored to Ni foam, and were characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and N2 adsorption–desorption experiments. Electrochemical properties were evaluated by cyclic voltammetry (CV) and galvanostatic cycling. Cycling performance shows that after 70 cycles the NiO nanorod-anchored Ni foam electrode can still deliver a stable reversible capacity up to 705.5 mA h g−1 and 548.1 mA h g−1 with a high coulombic efficiency (≥98%) at a constant current density of 1 A g−1 and 2 A g−1, respectively. The superior performance of the NiO electrode can be attributed to its favorable morphology and the excellent electrical contact between NiO and the current collector of Ni foam. The present strategy can be extended to fabricate other self-supported transition metal oxide nanostructures for high-performance lithium-ion batteries.