Abstract
The dc and small‐signal ac impedances of a flooded‐agglomerate element of a porous gas‐diffusion electrode have been calculated. The complete solution involves a nonlinear concentration profile within the agglomerate and requires numerical integration. An approximate solution has been developed leading to a simple equivalent circuit that is valid for most practical situations. The complete agglomerate model was combined with a thin‐film diffusion element and the total impedance was calculated. Transfer functions were developed that also allow the simplified agglomerate representation to be combined with the thin‐film element, greatly facilitating numerical fitting of the model to measured impedance data.