Thin BaCe[sub 0.8]Gd[sub 0.2]O[sub 3−δ] Protonic Electrolytes on Porous Ce[sub 0.8]Gd[sub 0.2]O[sub 1.9]–Ni Substrates

Thin proton-conducting electrolytes with thickness and a nominal composition were prepared over porous substrates composed of (CGO)–Ni. The fabrication method includes the simultaneous cofiring and solid-state reaction at of three screen-printed layers: mixed conducting anode layer, CGO, and an upper-coated layer. The resulting asymmetric membranes with geometry are gastight. The solid-state reaction resulted in the formation of ( i ) an electrolyte with large grains and high packing density and ( ii ) anode layer comprising finely grained and Ni particles with a thickness around . The layer morphology, phase distribution, and lattice composition has been investigated by X-ray diffraction, energy-dispersive spectroscopy scanning electron microscopy, and secondary-ion mass spectrometry. The preparation of the substrate by warm-pressing and tailoring of the porosity and sintering activity are also thoroughly described. DC-electrical conductivity and ac-electrochemical characterization showed that the supported Gd-doped barium cerate electrolyte produced by solid-state reaction has interesting proton-conduction properties for application in solid oxide fuel cells, hydrogen separation, and sensors.