Fabrication of Ni_0.5Cu_0.5Ba_0.05O_x coated SDC stereoscopic anode by hard template method for solid oxide fuel cells

The fabrication of porous and stereoscopic anode is crucial for the effective use of dry methane as fuel in solid oxide fuel cells (SOFCs). In this work, tubular SDC coated with Ni_0.5Cu_0.5Ba_0.05O_x (Ni_0.5Cu_0.5Ba_0.05O_x/SDC) was prepared by hard template method combined with wet impregnation method. For comparison, Ni_0.5Cu_0.5Ba_0.05O_x powder was also prepared by sol-gel method and then mixed with SDC to get anode Ni_0.5Cu_0.5Ba_0.05O_x-SDC. Corresponding electrolyte-supported unit cells Ni_0.5Cu_0.5Ba_0.05O_x/SDC|YSZ|LSM-YSZ and Ni_0.5Cu_0.5Ba_0.05O_x-SDC|YSZ|LSM-YSZ were then fabricated for the power generation performance and long-term stability test. Fueled with dry methane at 800℃ on a fuel cell with Ni_0.5Cu_0.5Ba_0.05O_x-SDC as anode, the maximum power density is only 324.99 mW/cm² and the voltage drops 5.60% after 10 h operation; however, with Ni_0.5Cu_0.5Ba_0.05O_x/SDC as the anode, the maximum power density reaches 384.54 mW/cm² and no degradation in voltage is observed for 100 h. As reveled by SEM, the narrow pores in Ni_0.5Cu_0.5Ba_0.05O_x-SDC anode are prone to block by carbon deposition; in contrast, Ni_0.5Cu_0.5Ba_0.05O_x/SDC has a three-dimensional porous structure for the diffusion of fuel and reactant gas. The surface of SDC fiber tube is coated by the catalyst particles, which can improve the three phase boundary and enhance the cell stability.