Solid Oxide Steam Electrolysis Anodes with Precisely Controlled Microstructure for Performance Analysis

Oxygen electrodes of Solid Oxide Electrolysis Cells (SOECs) have been manufactured using a spray deposition method with strictly controlled parameters to understand electrode transport, improve performance and extend electrolyser life time. The controlled parameters were the; particle size distribution, solid fraction of the ink, and spray deposition rate. The effect on physical properties; porosity, pore size, and the mass fraction of the individual ceramics in the solid phase as a function of distance from electrolyte, caused by controlling the above mentioned parameters was studied. The changes in performance of the cells with differing parameters were observed as; polarization responses, long term current-voltage behaviour, impedance spectroscopy and effective conductivities, measured with the van der Pauw method. The polarization responses gave valuable information to compare cells to those commercially available. The impedance spectroscopy of the cells allowed for the study of the changing physical properties effect on the electrochemical behaviour. Specifically the individual electrochemical processes; cell conductivity, oxygen gas diffusion, and oxygen evolution.