ELECTROCHEMICAL IMPEDANCE OF DISTRIBUTED IONIC STRUCTURES

Impedance of the cells employing reversible electrodes and a mixture o f powdered AgI and Ag4RbI5 as the solid electrolyte is measured. The e xistence of the intergrain impedance is discovered. The bulk conductiv ity, the capacitance of the electrical double layer, and resistance of the faradaic reaction of the mixture are shown to depend on the mixtu re composition in accordance with the percolation theory. Unlike these parameters, the dependence of the Warburg diffusion impedance on the composition does not obey equations of the percolation theory, but is defined by changes in the geometric contact area. This fact is explain ed within the model of adsorption relaxation of the electrical double layer.