Sinteractive anodic powders improve densification and electrochemical properties of BaZr0.8Y0.2O3-δ electrolyte films for anode-supported solid oxide fuel cells

The difficult sintering of BaZr0.8Y0.2O3-delta (BZY20) powders makes the fabrication of anode-supported BZY20 electrolyte films complex. Dense BZY20 membranes were successfully fabricated on anode substrates made of sinteractive NiO-BZY20 powders, prepared by a combustion method. With respect to traditional anode substrates made of powders prepared by mechanical mixing, the anode substrates made of the wet-chemically synthesized composite NiO-BZY20 powders significantly promoted the densification of BZY20 membranes: dense BZY20 films were obtained after co-pressing and co-firing at 1300 degrees C, a much lower temperature than those usually needed for densifying BZY20 membranes. Improved electrochemical performance was also observed: the supported BZY20 films maintained a high proton conductivity, up to 5.4 x 10(-3) S cm(-1) at 700 degrees C. Moreover, an anode-supported fuel cell with a 30 mu m thick BZY20 electrolyte film fabricated at 1400 degrees C on the anode made of the wet-chemically synthesized NiO-BZY20 powder showed a peak power density of 172 mW cm(-2) at 700 degrees C, using La0.6Sr0.4Co0.2Fe0.8O3-delta-BaZr0.7Y0.2Pr0.1O3-delta as the cathode material, with a remarkable performance for proton-conducting solid oxide fuel cell (SOFC) applications.