Electrochemical Spectroscopy of Proton Intercalation in γ-Mno2

Abstract
We have performed electrochemical studies of proton intercalation in several varieties of γ/ε-MnO2 using an original method which combines linear sweep voltammetry and potentiostatic intermittent titration technique. This technique gave for the first time a direct evidence of a two step intercalation process in the ramsdellite units of these compounds. Either 0.5 or 1 proton per manganese are accommodated in the 1×2 channels, as previously suggested by Maskell. The reversibility of these steps has been studied and is discussed in relation to the structural modifications induced by the proton intercalation.