Nanostructured and functionally graded cathodes for intermediate-temperature SOFCs

Nanostructured composite cathodes graded in both composition and microstructure have been successfully fabricated for the first time using a combustion chemical vapor deposition (CCVD) process. The functionally graded structures of these cathodes dramatically increase the rates of electrode reactions, enhance the transport of oxygen molecules to the active reaction sites, and significantly improve the compatibility between the electrodes and other cell components. As a result, extremely low interfacial polarization resistances and high power densities have been achieved at operating temperatures of 600–850°C, suggesting that the CCVD process has great potential for cost-effective fabrication of nanostructured fuel cell electrodes.