Combined Cu-CeO2/YSZ and Ni/YSZ dual layer anode structures for direct methane solid oxide fuel cells

Abstract

In this study, a conventional Ni/yttria-stabilized zirconia (YSZ) anode and a new Cu-CeO2-YSZ anode structure were assembled in an attempt to combine the advantages of both structures for use in direct methane solid oxide fuel cells. For this purpose, only a limited region (20m) of NiO/YSZ was deposited at the boundary of the electrolyte to benefit from the superior catalytic activity of Ni in the cells, while the rest of the cell benefited from the Cu-CeO2-YSZ anode structure, which does not cause cracking reactions. First, the effects of different pore formers on the anode skeleton, as well as the interactions of the Ni-Cu species in the anode skeleton, are discussed. Then, the NiO/YSZ-interlayer-containing button cells with different thicknesses (20) and different ratios of NiO (40wt%, 50wt%, and 60wt%) were studied. After the examination of the cells, 2 model cells with outstanding performance and 2 additional internal reference cells, conventional Ni/YSZ and Cu-CeO2-YSZ, were scaled up, and performance analysis and long-term stability studies were carried out. As a result, for solid oxide fuel cells with increased carbonization resistance (around 6% performance loss due to carbonization after 100-hour stability testing) and 86.1% of the initial performance of the conventional Ni/YSZ anode structure, a 15-m-thick 40wt% NiO/60wt% YSZ interlayer with a dual layer anode structure is proposed.