Electrochemical properties of lead dioxides formed on various lead alloy substrates

Electrochemical properties of lead dioxides, formed on various lead alloy substrates (Pb–In, Pb–Sn, Pb–Sb, Pb–Tl and Pb–Bi), were investigated using electrochemical techniques with X-ray diffraction (XRD) and electron probe micro analyzer (EPMA). Additive elements, selected by applying Hume-Rothery rules, have similar atomic radius and electronegativity to lead. The reduction capacity of lead dioxides that were formed on Pb–Sb and Pb–Sn alloy substrates decreased, whereas the reduction capacity of lead dioxides formed on Pb–In, Pb–Tl and Pb–Bi alloy substrate increased, compared with those formed on the pure lead substrate. The change of the lattice constant of β-lead dioxides and the existence of additive elements in the lead dioxide layer were confirmed from the analysis results of XRD and EPMA. We concluded that the substitution of additive elements for lead in the β-lead dioxide caused the change of its lattice constant to affect the reduction capacity.