Porous, robust highly conducting Ni-YSZ thin film anodes prepared by magnetron sputtering at oblique angles for application as anodes and buffer layers in solid oxide fuel cells

Abstract

a b s t r a c tPolyactive ® membranes show promising properties for CO 2 separation from flue gas. An investigation of different module types using Polyactive ® membranes was carried out for this paper. A test rig was built to explore, amongst other process parameters, the pressure drop in envelope-type membrane modules. The experimental data and simulation results were compared with quite good consistency. This validation enabled further simulations for different modules in a virtual pilot plant configuration. Applying the data from the pilot plant simulation to a reference power plant, the scaled-up cascaded membrane system was analyzed using different membrane modules. Considering the required membrane area, energy consumption and pressure drop in different modules, a counter-current membrane module configuration exhibited the best performance and had a marginal advantage in comparison with the chemical absorption process.

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

“…It is important to note that these films exhibited major differences in structure and porosity compared to dense non-porous films deposited at normal incidence angle, as previously described [6,7]. The small amount of available material and the opacity of our films precluded conventional BET and optical measurements of porosity, respectively.…”

“…We have previously shown [6,7] that anode nanostructure can favorably affect the performance of very thin film anodes of the type investigated here. In the present, our aim was to investigate the effect of systematically varying anode nano-scale structure by (i) changing the thickness of alternating layers in a composite anode and (ii) fully intermixing the components, in each case varying the number of three phase boundaries and hence, hopefully, anode performance.…”

“…The target-substrate distance was 5 cm with an angle of 80°between target and substrate normal and the deposition rate was in the order of 2 μm h −1 in all cases. A more detailed description of the deposition procedure may be found elsewhere [5][6][7]. Oblique angle deposition resulted in formation of highly porous thin film anodes, crucial for achieving superior structural and electrical properties.…”

“…Instability due to mechanical stresses caused by differences in thermal expansion coefficients at key interfaces can result in cell failure [2][3][4]. We have shown that Ni-YSZ thin film anodes deposited on YSZ electrolyte by means of magnetron sputtering at oblique incidence yield thermally robust anode/electrolyte structures that resist delamination under temperature cycling and also provide good electrochemical performance under SOFC conditions [5][6][7]. The columnar anode architecture generated by this method provides excellent porosity and extensive triple-phase boundaries well suited to the intended application.…”

“…The columnar anode architecture generated by this method provides excellent porosity and extensive triple-phase boundaries well suited to the intended application. Moreover, this microstructure in conjunction with the extreme thinness of the anodes (a few microns), allows them to accommodate interfacial strain far better than the corresponding dense thin film cermets [7,8].…”