A method for producing ultra-high power density solid oxide fuel cells
(SOFCs). The method involves the formation of a multilayer structure
cells wherein a buffer layer of doped-ceria is deposited intermediate a
zirconia electrolyte and a cobalt iron based electrode using a colloidal
spray deposition (CSD) technique. For example, a cobalt iron based
cathode composed of (La,Sr)(Co,Fe)O(LSCF) may be deposited on a zirconia
electrolyte via a buffer layer of doped-ceria deposited by the CSD
technique. The thus formed SOFC have a power density of 1400 mW/cm.sup.2
at 600.degree. C. and 900 mW/cm.sup.2 at 700.degree. C. which constitutes
a 2-3 times increased in power density over conventionally produced
SOFCs.