A one-dimensional model of gas-diffusion electrodes for O-2 reduction

A one-dimensional mathematical model of gas-diffusion electrodes for oxygen reduction is presented to investigate the effect of gas composition and ma ss-transport limitation on the current-potential curve. A simple explicit a nalytical solution has been obtained, which works well for conditions relat ively far from the limiting current situation. In the proximity of the limi ting current this basic model has to be slightly modified and an explicit a nalytical solution cannot be found. Nevertheless, the form of the equations remains simple, making possible direct and easy identification of the para meters of the electrode. The proposed models have been compared favorably w ith experimental data and with the results of a more complex electrode mode l, developed by other authors. In addition, they have been used as a tool t o estimate the gradual aging of an air electrode. (C) 2001 The Electrochemi cal Society.