Manganese dioxide in dry cell electrodes

The working mode of manganese dioxide as the active constituent of battery electrodes is described. Only 30 p.c. of the electrode volume is occupied by the manganese dioxide itself. About 50 p.c. are the pore volume, and another 10 p.c. are filled by the electron conducting material, e.g. carbon black. The remaining 10 p.c. by volume are occupied by solid salts. The complicated electric processes within the porous electrodes are treated concisely.

In spite of numerous theoretical and experimental investigations, the discharging reaction of manganese dioxide is known only in a formalistic or thermodynamic approximation. The processes in the interface between the phases can only be studied by the application of analogous conclusions, so far. Nevertheless, there is no doubt that the knowledge and deeper insight into the electronic conductivity of manganese dioxide will influence the future battery development very much.