INVESTIGATIONS OF THE NEGATIVE PLATE OF LEAD ACID CELLS .3. MODEL-CALCULATIONS OF THE IMPEDANCE OF SELF-SIMILAR POROUS-ELECTRODES

In this paper a model for the calculation of the admittance (reciproca l impedance) of a porous metal electrode is derived, under anodic cons tant-current conditions, during precipitation of an insoluble salt at the metal/electrolyte interface. An example of the discharge, at low c urrent density, of the negative plate in a lead/sulphuric acid battery during which lead sulphate is formed. The discussion is based on the assumption that porosity has a self-similar fractal character. The imp edance of fractal electrodes will be discussed in terms of geometrical and physical parameters.