Influences of Zn-Sn-Al-Hydrotalcite Additive on the Electrochemical Performances of ZnO for Zinc-Nickel Secondary Cells

Zn-Sn-Al-LDH as a novel additive of ZnO electrode has been prepared through a simple hydrothermal process. The effects of novel additive on electrochemical performances of ZnO have been investigated by charge-discharge cycling test, cyclic voltammetry (CV), Tafel polarization tests and electrochemical impedance spectroscope (EIS) measurement. The Scanning electron microscopy (SEM) of ZnO electrodes after cycling show that Zn-Sn-Al-LDH as ZnO electrode additive can suppress the dendrite growth of ZnO, due to its special layer structure and better stability in alkaline electrolyte. Compared with the pure ZnO electrode, the ZnO electrodes added with Zn-Sn-Al-LDH additive, especially the ZnO electrode added with 24% Zn-Sn-Al-LDH additive, show better cycle performance. Meanwhile, the results of CVs exhibit better reversibility, the Tafel polarization curves reveal the better anti-corrosion property and the EIS show a lower charge-transfer resistance for the ZnO electrodes added with Zn-Sn-Al-LDH additive than those of pure ZnO electrode. Zn-Sn-Al-LDH with the special layered structure is a novel, high efficient additive of ZnO and can significantly improve electrochemical performances of ZnO. (C) 2014 The Electrochemical Society. All rights reserved.