Proton electrochemical insertion in different crystalline forms of manganese dioxide

Abstract

The reduction in concentrated KOH electrolyte of three allotropic forms of MnO₂, ramsdellite (R), pyrolusite (p) and γ-MnO₂(material described as an intergrowth of ramsdellite and pyrolusite type blocks, R_1–xP_x), shows that the latter form has the highest reduction potential, demonstrating that structural disorder increases the Fermi-level energy of γ-MnO₂.