Thermal stability and performance enhancement of layer-structured platinum cathode in solid oxide fuel cell by protecting layer of samarium doped ceria

Abstract

In this thesis, fabrication of multi-layered cathode structure with platinum and samarium doped ceria for enhancement of thermal stability is demonstrated. Platinum has superior catalytic activity for oxygen reduction reaction, but its nanoporous structure is vulnerable to thermally-driven agglomeration, resulting severe irreversible fuel cell performance drop. Samarium doped ceria has high oxygen ion conductivity despite of low operating temperature. Compared to monolayer platinum cathode, multi-layered sandwich structure cathode, alternatively stacked samarium doped ceria and platinum with 4 layers, and 8 layers, showed higher electrochemical reaction and thermal stability. Maximum fuel cell output power with 8 layered structure was more than two times higher compared to platinum monolayer at operating temperature 500°C.