Infiltration of mixed ionic/electronic conducting nanocatalysts into the anodes of solid oxide fuel cells allows the hydrogen oxidation reaction to occur at double-phase boundaries (DPBs) rather than being confined only to the triplephase boundaries (TPBs). In this research, we use a combination of crosssectional scanning electron microscopy, three-dimensional (3D) reconstruction, and electrochemical methods to characterize both baseline and gadolinium-doped ceria (GDC)-infiltrated symmetric cells, with the goal of establishing a comparison between the density of electrochemically active sites in uninfiltrated and GDC-infiltrated cells. Electrochemical impedance spectroscopy and distribution of relaxation times analysis showed GDC infiltration decreased the overall polarization of the anode by a factor of 8.789 and decreased the resistance associated with the reactions at the TPBs/DPBs by a factor of over 219. By quantifying expected GDC deposition morphology in the Ni/YSZ anode, it is estimated that reactions occur in the baseline cell up to 84 nm from the active TPB lines.

Solid oxide electrolysis cells (SOECs) are highlighted as promising power-to-gas (P2G) devices that can provide a reliable supply of hydrogen gas to store renewable energy. Despite the potential of SOECs, there are many challenges facing their commercialization. In this work, the influence of process parameters and fuel electrode optimization on initial SOEC performance (500 hours) is investigated. Electrolysis experiments were performed with both GDC (gadolinia doped ceria)-infiltrated and uninfiltrated Ni-YSZ (yttria stabilized zirconia) fuel electrodes under various hydrogen flow rates with different ratios of H2-H2O and current densities. All cells marginally improve in performance initially, then undergo a brief period of rapid performance degradation followed by stabilization. The observed three stages of cell performance, in terms of length of time and rate of change, are found to be dependent on the type of fuel electrode and experimental process parameters used.

Stainless steel interconnects in solid oxide fuel cells can lead to chromium poisoning of the cathode, necessitating the use of protective coatings. Electrophoretic deposition is an efficient method to deposit coatings on substrates with complex microstructures. In this study, four spinel coatings; CuMn2O4, CuNi0.2Mn1.8O4, MnCo2O4, and MnFe0.34Co1.66O4, were deposited by direct-current electrophoretic deposition on flat SUS430 stainless steel substrates. The coatings were evaluated on multiple criteria, including microstructural stability, conductivity, Cr gettering ability, and the ability to act as a diffusion barrier at 700°C and 800°C. It was concluded that CuNi0.2Mn1.8O4 is an excellent candidate at temperatures at and below 700oC, while MnFe0.34Co1.66O4 coatings perform better at higher temperatures.

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