Ni/YSZ and Ni-CeO_2/YSZ anodes prepared by impregnation for solid oxide fuel cells

摘要

In this paper, Ni/YSZ and Ni-CeO_2/YSZ anodes for a solid oxide fuel cell (SOFC) were prepared by tape casting and vacuum impregnation. By this method, the Ni content in the anode could be reduced compared to the traditional tape casting method. It was found that adding CeO_2 into the Ni/YSZ anode by a Ni(NO_3)_2 and Ce(NO_3)_3 mixed impregnation could further enhance cell performance. This was investigated in H_2 at 1073 K. XRD patterns indicated that CeO_2 and Ni were separate phases, and the CeO_2 addition could enhance the Ni dispersion on the YSZ framework surface which was observed by SEM images. It was shown that adding CeO_2 into the Ni anodes could decrease the cell polarization resistance. The maximum power density for cells with 25 wt.% Ni, 5 wt.% CeO_2-25 wt.% Ni/YSZ, or 10 wt.% CeO_2-25 wt.% Ni/YSZ anode was 230mWcm~(-2), 420mWcm~(-2) and 530mWcm~(-2), respectively, in H_2 at 1073 K. The OCV for these cells was 1.05-1.09 V, indicating that a dense electrolyte film was obtained by co-firing porous YSZ layer and dense YSZ layer.