화학공학소재연구정보센터
Journal of Power Sources, Vol.224, 236-240, 2013
Enhanced cycling performance of Al-substituted alpha-nickel hydroxide by coating with beta-nickel hydroxide
Al-substituted alpha-nickel hydroxide is modified by coating with pure beta-nickel hydroxide in an attempt to improve its cycling performance. The crystal structure and morphology of the prepared samples are examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical performances of the bare and the beta-nickel hydroxide coated Al-substituted alpha-nickel hydroxides are characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and charge/discharge tests. The results show that a beta-nickel hydroxide coating on Al-substituted alpha-nickel hydroxide decreases the charge-transfer resistance and increases the specific discharge capacity. In particular, the enhancement of the capacity retention of beta-nickel hydroxide coated Al-substituted alpha-nickel hydroxide is significant, maintaining 92.5% of the maximum capacity after 100 cycles at a charge/discharge rate of 0.5 C, whereas that of bare Al-substituted alpha-nickel hydroxide is only 53.6%. (C) 2012 Elsevier B.V. All rights reserved.