Electrochemical Behavior of the Manganese‐Substituted Nickel Hydroxides

The electrochemical behavior of hydrated manganese‐substituted nickel hydroxides in Ni/Cd cells was studied. Partial substitution of manganese for nickel was shown to induce stabilization of the discharge capacity during long‐term cycling. Such behavior is related to the very small discrepancy between the interslab distances of the oxidized material (γ‐phase) and the reduced material (interstratified phase I E constituted of random distribution of γ‐ and α‐type interslab spaces), which strongly reduces the mechanical strains on cycling. Manganese also seems to slow noticeably the formation of the β(III)/β(II) couple on cycling, which was a crucial point for the homologous cobalt system, resulting in a significant decrease of the capacity vs. cycle number.