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

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 and exhibit electron conductivity. Gel zones are composed of hydrated lead dioxide, , 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.