Materials Research Bulletin, Vol.86, 257-267, 2017
Differences in the effects of aluminum/ytterbium/cobalt on the structural stability and electrochemical properties of nickel hydroxide
Alpha nickel hydroxide has better performance than commercial beta nickel hydroxide. However, the main defect is that alpha-phase is easily transformed to beta-phase Ni(OH)(2) upon aging in a strong alkaline solution. The different effects of the doping cations Al3+, Yb3+ and Co2+ on the chemical composition, morphology, structure and electrochemical properties of Ni(OH)(2) are studied, with the same doping ratio. The results demonstrate that the synergistic effect of the ternary doping samples is better than the binary. The Al-Yb-Co-Ni(OH)(2) exhibits excellent structural stability, which can stay the pure alpha-phase in strong alkaline solutions over 60 days. The CV measurements demonstrate that the relevant electrode has the highest proton diffusion coefficient, indicating a higher electrochemical activity and faster reaction kinetics due to the fast ionic transportation. Moreover, the above electrode has the higher charge efficiency, better reversibility and cycle stability. (C) 2016 Elsevier Ltd. All rights reserved.
Keywords:Nanostructures;Chemical synthesis;Crystal structure;Electrochemical measurements;Electrochemical properties