Determination of contact angle in porous molten-carbonate fuel-cell electrodes

A method of capillary rise (gravimetrically measured) has been investigated for determination of the electrolyte contact angle in porous electrodes for the molten-carbonate fuel cell. The experiments were conducted on LiCoO2 electrodes in air, at different temperatures (555 to 740 degrees C), to monitor the influence of the temperature an the contact angle. The results indicate that the contact angle decreases with increasing temperature. The results obtained were of good reproducibility, and the method shows promise as a useful tool in characterization of wetting phenomena in porous fuel-cell electrodes, making it possible to study electrodes as manufactured, and under electrochemical conditions. The wetting-in was characterized also by post-test measurements, and it was found that the wetting-in front (i.e., from no electrolyte to fully flooded), extends over several millimeters.