Fabrication and lithium storage performance of three-dimensional porous NiO as anode for lithium-ion battery

Three-dimensional porous NiO is prepared on Ni foam by a thermal treatment method at various temperatures. The morphology and structure of porous NiO are characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The electrochemical properties of three-dimensional porous NiO anode are evaluated by galvanostatic discharge-charge cycling, cyclic voltammery, and impedance spectral measurements on cells with lithium as the counter and reference electrodes. Results show that porous NiO delivers a stable capacity of 520 ± 20 mAh g^-1 with no noticeable capacity fading up to 30 cycles when cycled in the voltage range 0.05-3.0 V at rate of 0.2 C. The porous NiO exhibits higher reversible capacity, better cycleability, as well as higher rate capability in comparison to NiO foil. The observed cyclic voltammograms and impedance spectra are analyzed and interpret a redox reaction of NiO-Ni⁰ with formation and decomposition of Li₂O. The excellent electrochemical performance of porous NiO can be attributed to its large surface area, which lowers the current density of NiO reaction interface, and then an alternative anode is provided for lithium-ion batteries.