STUDY ON Mn-SUBSTITUTED α-NICKEL HYDROXIDE

摘要

We have studied charge / discharge reaction and other electrochemical characteristics of Mn-substituted α-Ni(OH)_2 in terms of the oxidation state of Ni, Mn and the phase transition by X-ray diffraction, XAFS and by cyclic voltammetry. Two reactions of the material were identified as α / γ reaction and P(II) / γ reaction, respectively. In both of these two reactions, it was found Ni transferred more than one electron, and Mn stabilized in IV+ state. It was assumed that Mn-substitution induced local deformations in the metal-oxygen layer, and thus promoted the generation of γ-phase.