The Lead‐Acid Battery Lead Dioxide Active Mass: A Gel‐Crystal System with Proton and Electron Conductivity

Abstract

Up to now, the positive lead dioxide active mass (PAM) has been treated as a crystal system. Its behavior, however, could not be fully explained by its crystal nature. In the present paper, a new approach is suggested which views PAM as a gel-crystal system. Crystal zones are built of PbO~. and exhibit electron conductivity. Gel zones are composed of hydrated lead dioxide, PbO(OH)~, that forms linear polymer chains. These allow electrons to move in the gel hopping from one Pb 4 § ion to the other along the polymer chain and from one polymer chain to the other between the crystal zones. This determines the electron conductivity of the gel. Besides, PAM seems to meet all requirements of a good proton (ion) conductor. This gel-crystal structure of PAM explains more deeply its electrochemical behavior during charge, discharge, and overcharge as well as the relation between PAM crystallinity and polarization and plate capacity.

The influence of F− doping on the activity of PbO2 film electrodes in oxygen evolution reaction

“…6 presents the style of the linear chain of F-doped ␤-PbO 2 [16]. The polymer has electron and proton conductivity [19]. On the other hand, the polymer chains are connected to crystal zones of PbO 2 .…”

Electrodeposition of fluorine-doped lead dioxide

“…An association of fluorine with Pb(II) is not surprising if it is seen in the light of the models of PbO 2 proposed by Pavlov et al [41][42][43] and by Giovanoli and Rüetschi [44]. The latter authors proposed the following composition formula for lead dioxide:…”

Electrocrystallization of lead dioxide: Influence of early stages of nucleation on phase composition

“…Lead ions replacement both in hydrated and crystal zone would cause not only the change of amount of oxygen-containing particles in each zone, but their binding energies, that in turn will change the electrocatalytic activity of materials. The radii of the ions [12] in the oxidation state + 2, + 3 (Bi 3+ In the present work we examine early stages of electrocrystallization of PbO 2 from methanesulfonate electrolytes that contain various ionic additives (Bi 3+ , Ce 3+ , Sn 4+ , [NiF 6 ] 2-, [SnF 6 ] 2-) and identify correlations between the deposition conditions and phase composition of coatings. It should be pointed out that such data is currently absent in the literature.…”