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Solid Oxide Cell (SOC) electrodes have been fabricated by infiltration of a porous gadolinia-doped ceria (GDC) scaffold with nickel nano-particles. Interconnected Ni structures were achieved with a conductivity of 620S/cm at 700 • C at a Ni content of only 14 wt%. Electrochemical performance in fuel cell mode was evaluated using both two-electrode symmetrical cell and three-electrode fuel cell measurements over a range of temperatures (580-750 • C) and hydrogen concentrations (20-80%). At 750 • C and in 50%H 2 -50%N 2 the area specific resistance was as low as 0.14 • cm 2 . The charge transfer activation energy of hydrogen oxidation on these electrodes was ∼0.53-0.58 eV, lower than that previously reported for conventional Ni-YSZ electrodes. The microstructure of the electrode was studied using Scanning Electron Microscopy. Formation of Ni agglomerates and increased ohmic resistance was observed over approximately 100 hrs of cell operation at 690 • C and 50%H 2 -50%N 2 , though charge transfer resistance was little affected. The results indicate the feasibility of percolated Ni-infiltrated GDC electrodes for future application in SOCs and highlight some of their challenges.

Additive manufacturing can potentially offer a highly-defined electrode microstructure, as well as fast and reproducible electrode fabrication. Selective laser sintering is an additive manufacturing technique in which three-dimensional structures are created by bonding subsequent layers of powder using a laser. Although selective laser sintering can be applied to a wide range of materials, including metals and ceramics, the scientific and technical aspects of the manufacturing parameters and their impact on microstructural evolution during the process are not well understood. In the present study, a novel approach for electrode fabrication using selective laser sintering was evaluated by conducting a proof of concept study. A Ni-patterned fuel electrode was laser sintered on an yttria-stabilized zirconia substrate. The optimization process of laser parameters (laser sintering rate and laser power) and the electrochemical results of a full cell with a laser sintered electrode are presented. The challenges and prospects of using selective laser sintering for solid oxide cell fabrication are discussed.

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