Design and fabrication of three-dimensional solid oxide fuel cells

A novel design for a three-dimensional (3-D) solid oxide fuel cell (SOFC) along with its method of fabrication is reported. This structure utilizes two 3-D channels that are separated by unique anode/electrolyte/cathode walls that thereby increases the active volumetric surface areas of the electrodes used for the chemical reactions. To implement this structure, a graphite template having one 3-D interconnected channel is successively coated with anode (NiO–YSZ), electrolyte (YSZ), and cathode (LSM–YSZ) slurries, followed by heat-treatment at elevated temperatures. This produces an additional 3-D channel that has the NiO–YSZ layer as a replica of the graphite template, while preserving the pre-existing channel that has the LSM–YSZ layer. The thickness of the NiO–YSZ layer, which provides mechanical stability, is controlled by adjusting the number of dip-coating cycles. Using this approach, it is possible to fabricate a ∼10 mm cubic SOFC without any notable defects, as well as to control the microstructures of the NiO–YSZ/YSZ/LSM–YSZ walls.