Synthesis, spectroscopic and electrochemical performance of pasted β-nickel hydroxide electrode in alkaline electrolyte

Abstract

β-Nickel hydroxide (β-Ni(OH)2) was successfully synthesized using precipitation method. The structure and property of the β-Ni(OH)2 were characterized by X-ray diffraction (XRD), Fourier Transform infra-red (FT-IR), Raman spectra and thermal gravimetric–differential thermal analysis (TG–DTA). The results of the FTIR spectroscopy and TG–DTA studies indicate that the β-Ni(OH)2 contains water molecules and anions. The microstructural and composition studies have been performed using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) analysis. A pasted-type electrode is prepared using β-Ni(OH)2 powder as the active material on a nickel sheet as a current collector. Cyclic voltammetry (CV) and Electrochemical impedance spectroscopy (EIS) studies were performed to evaluate the electrochemical performance of the β-Ni(OH)2 electrode in 6M KOH electrolyte. CV curves showed a pair of strong redox peaks as a result of the Faradaic redox reactions of β-Ni(OH)2. The proton diffusion coefficient (D) for the present β-Ni(OH)2 electrode material is found to be 1.44×10−12cm2s−1. Further, electrochemical impedance studies confirmed that the β-Ni(OH)2 electrode reaction processes are diffusion controlled.