Synthesis, Characterization and Electrochemical Properties of Board-like Al-substituted Alpha Nickel Hydroxides

Abstract

A board-like Al-substituted α-Ni(OH)2 has been synthesized via a optimizing chemical precipitation method, in which polyethylene glycol is used as the structure-directing reagent. Structural and morphological characterizations of these nanomaterials are performed using powder X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The component and thermal stability of the sample are respectively measured by FT–IR and thermogravimetry (TG). Its electrochemical properties are evaluated by cyclic voltammetry (CV) and galvanostatic charge-discharge technique in 6 M KOH aqueous electrolyte. The results show that the maximum capacity of 331 mAh g–1 for 10 mol% Al-substituted α-Ni (OH)2 is obtained at 0.2 C rate. Furthermore, the electrodes have very high discharge rates being able to maintain 93% and 85% of the nominal capacity at the discharge rates of 1.0 and 2.0 C, respectively.