Analysis Method of Oxygen Permeation Resistance of Ionomer in Cathode Catalyst Layer in PEFC

• Published in: ECS transactions 2022-09, Vol.109 (9), p.153-167
• Main Authors: Ogawa, Hikaru, Kageyama, Miho, Gyoten, Hisaaki, Kawase, Motoaki
• Format: Article
• Language: English
• ISSN: 1938-5862; 1938-6737
• DOI: 10.1149/10909.0153ecst

For oxygen to reach platinum surface and react with protons, oxygen has to permeate through ionomer which is ion conductive polymer on the platinum surface. The oxygen permeation resistance of ionomer lowers the current density. In order to investigate governing factors of oxygen reduction reaction (ORR) rate, the oxygen permeation resistance should be analyzed. In this study, instead of commercial supported catalyst, a platinum slits catalyst was prepared by coating the platinum slabs with ionomer and ORR rate was measured. In order to determine the oxygen permeance, a dimensionless cathode isothermal one-dimensional model was applied. Although we had reported that the effectiveness factor of cathode catalyst layer (CCL) was a function of 4 dimensionless moduli derived from mass balance, new dimensionless moduli to quantitatively evaluate the oxygen permeance were introduced. Oxygen permeance at the temperature of 80 °C and inlet relative humidity (RH) of 0.76 was determined.