Fundamental Understanding of Oxygen Reduction Reaction Kinetics and Improving Electrochemical Performance of Solid Oxide Fuel Cell Cathode

X. Liu
West Virginia University, US

Keywords: fuel cells, cathode, solid oxide

Summary:

Solid oxide fuel cells (SOFCs) are promising candidates for future energy conversion systems because of their high energy conversion efficiency than those for conventional heat engine systems and other types of fuel cells. However, there are several major technical hurdles to overcome before SOFC’s wide applications, namely (1) impurity effects on anode, (2) developing interconnect coatings to mitigate Cr-poisoning related issues, and (3) developing highly efficient and stable cathode. Infiltration methods have been widely employed to improve the oxygen reduction reaction (ORR) kinetics of SOFC cathode. The principal assumption in infiltration is that infiltrants having high oxygen absorption capabilities enhance oxygen flux into the cathode and thus improve the cathode performance. However, few systematic investigations exist on ORR mechanisms in infiltrated SOFC cathodes. In this talk, we report our studies on several issues fundamental related to infiltrated SOFC cathode: (1) Improving Data Accuracy of Electrical Conductivity Relaxation (ECR) Method; (2) Using ECR to Characterize Oxygen Interfacial Exchange Behavior; and (3) ORR Modeling in infiltrated Cathode. The preliminary results show that over-potential, as well as other materials’ intrinsic characters, have important effect on ORR behavior in infiltrated cathode.