High performance novel gadolinium doped ceria/yttria stabilized zirconia/nickel layered and hybrid thin film anodes for application in solid oxide fuel cells

• Published in: Journal of power sources Vol. 363; pp. 251 - 259
• Main Authors: Garcia-Garcia, F.J., Beltrán, A.M., Yubero, F., González-Elipe, A.R., Lambert, R.M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 30.09.2017
• Subjects: Layered and hybrid structures; Magnetron sputtering; Oblique angle deposition; SOFC; Thin film anodes; Oblique angle deposition; Layered and hybrid structures; Magnetron sputtering; Thin film anodes; SOFC
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2017.07.085

Magnetron sputtering under oblique angle deposition was used to produce Ni-containing ultra thin film anodes comprising alternating layers of gadolinium doped ceria (GDC) and yttria stabilized zirconia (YSZ) of either 200 nm or 1000 nm thickness. The evolution of film structure from initial deposition, through calcination and final reduction was examined by XRD, SEM, TEM and TOF-SIMS. After subsequent fuel cell usage, the porous columnar architecture of the two-component layered thin film anodes was maintained and their resistance to delamination from the underlying YSZ electrolyte was superior to that of corresponding single component Ni-YSZ and Ni-GDC thin films. Moreover, the fuel cell performance of the 200 nm layered anodes compared favorably with conventional commercially available thick anodes. The observed dependence of fuel cell performance on individual layer thicknesses prompted study of equivalent but more easily fabricated hybrid anodes consisting of simultaneously deposited Ni-GDC and Ni-YSZ, which procedure resulted in exceptionally intimate mixing and interaction of the components. The hybrids exhibited very unusual and favorable IV characteristics, along with exceptionally high power densities at high currents. Their discovery is the principal contribution of the present work. •MS at oblique angle is effective to fabricate alternating YSZ-Ni and Ni-GDC anodes.•MS-OAD allows the fabrication of nanostructured hybrid Ni-YSZ-GDC anodes in one pot.•Such films have enhanced porosity compared to typical magnetron sputtered cermets.•They have extensive three phase boundaries and so very high electrical conductivity.•Enhanced porosity permits large volume expansions and relief of thermal stresses.