화학공학소재연구정보센터
Journal of Power Sources, Vol.438, 2019
Nickel-copper based anodes for solid oxide fuel cells running on hydrogen and biogas: Study using ceria-based electrolytes with electronic short-circuiting correction
Cerrnet compositions based on Nickel-Copper alloys with gadolinium doped ceria as the ceramic matrix, Ni1-xCuxO (x = 0, 0.4 and 0.8 mol%) with 50 wt% CGO (Ce0.9Gd0.1O1.95), are assessed as possible anodes for SOFCs operating in H-2 and biogas fuels. Equivalent circuit modelling is employed to evaluate the total polarisation resistance of cermet anodes with correction of data for electronic short-circuiting that may arise when using Ce0.9Gd0.1O1.95 (CGO) electrolytes under reducing conditions. Data analysis highlights that presence of electronic leakage in CGO electrolyte can lead to severe underestimation of total polarisation resistance in the case of H-2 fuel, with this deviation becoming more serious with increasing temperature. In contrast, less significant effects are noted under biogas in similar conditions, due to a less reducing nature of this fuel. The results underscore that anode characteristics are highly dependent on the effective oxygen partial pressure of working gas atmosphere and that suitable correction of data is imperative before discussion. Corrected values for polarisation resistance in each fuel reveal the Nickel-Copper alloy cermet with copper content of x = 0.4 to be beneficial under the biogas atmosphere, while, conversely, the pure Ni-cermet is shown to be the peak performing composition in H-2 fuel.