Development of Solid Oxide Fuel Cell Anodes Using Metal-Coated Pore-Forming Agents

Adding Ni-coated graphite particulates to a tape casting colloidal suspension is capable of creating a sintered solid oxide fuel cell anode with a critical percolation threshold for conductivity significantly lower than conventional anode materials. For example, conductivity at 800°C reached over 1200 Ω⁻¹·cm⁻¹ in these anodes at a Ni volume below the percolation threshold reported for conventional anode materials. This behavior was explained based on an "effective" Ni content, V _Nieff, which includes the graphite portion of the particle. In the green tape, V _Nieff controls the creation of a percolating network of Ni. However, when the graphite burns away, it leaves a percolated Ni network at a much lower volume fraction than would otherwise be required.