An Interfacial Nanospike-Structured Cathode for Low Temperature Solid Oxide Fuel Cells

Lowering operating temperatures is a promising strategy to improve the durability and reduce the cost of solid oxide fuel cell (SOFC) systems. However, the ohmic and polarization resistance would increase significantly at low temperatures (500-700 ^oC), particularly that of cathode electrode due to sluggish oxygen reduction reactions (ORRs). To reduce polarization loss at low temperatures, cathode materials have been studied extensively. The high performance cathode electrodes were also obtained through nano-scale engineering enabled by infiltration technique. Essentially the infiltration is an additive approach to add catalytically active materials into porous cathode to enhance the ORRs. Here we report the fabrication and evaluation of a novel interfacial nanospike-structured cathode. The growth of interfacial nanospikes on the pore walls of the cathode was enabled by a discharge treatment under low-temperature sintering process. The electrochemical performance of the corresponding button cells was well demonstrated at low operating temperatures of 350-550 ^oC. The stability of interfacial nanospikes was also examined under thermal-cycling conditions.