Preparation of ZnO Nanorods with Lattice Vacancies and Their Application in Ni-Zn Battery

Abstract

As a type of environmental benign secondary battery with high power density, Ni-Zn battery is often limited by the weakness of negative electrode materials in the applications. In this work, ZnO nanorods (NRs) with high performance were synthesized by Sol-Gel process with hexamethylenetetramine (HMT) as template and subsequent thermal annealing treatment. Morphology, crystalline structure and surface functional groups of ZnO NRs were characterized by transmission electron microscope (TEM), X-ray powder diffraction (XRD) and Fourier-transform infrared spectroscope (FT-IR), respectively. X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) measurements reveal that ZnO NRs have carbon layers on the surface and vacancies in the lattice. Tafel tests and electrochemical impedance spectroscopy (EIS) show that the corrosion current and charge transfer resistance of ZnO NRs-based electrodes are reduced by 40% and 62%, respectively, compared with commercial ZnO. Further investigation show that Ni-Zn batteries fabricated with ZnO NRs have better cycling performances. After 100 cycles at a current density of 1 A•g-1 , the capacity retention rate of ZnO NRs is 92%, which is significantly higher than that of commercial ZnO powder (32%).