Gadolinium-Doped Ceria Room-Temperature Sputtered Thin Barrier Layers in Large-Area Solid Oxide Fuel Cells: Influence of Their Thickness and Thickness Gradient on the Cathodic Processes

Understanding the intricate electrochemical processes in solid oxide fuel cell (SOFC) components, especially air electrodes, is crucial for enhancing device performance and durability. In this work, following recent results showing important improvements in the electrochemical performance of SOFCs with room-temperature sputtered gadolinium-doped ceria (GDC) barrier layers, we investigate by standard Distribution of Relaxation Time (DRT) analysis the influence of the GDC thickness and uniformity on the cathodic reaction kinetics. The outcomes highlight the role played by the GDC thickness in the oxygen reactions at the electrolyte/cathode interface and the GDC thickness uniformity in the anode electrochemical charge transfer reactions involving oxygen ions from the cathode. The results of our work, obtained for industrial-scale SOFCs, are particularly interesting in view of enhancing both their performance and stability.