Quantifying Microstructural Degradation in GDC-Infiltrated Fuel Electrodes in Reversible Solid Oxide Cells

Abstract

Reversible solid oxide cells (RSOCs) can convert between hydrogen or other fuels and electricity in both directions, offering a promising application as tools for mitigating gaps between renewable energy supply and demand in the electric grid. Many advanced RSOC electrode materials achieve good performance stability during operation—for example, NNO | NNO-NDC50 | GDC10 | YSZ | Ni-YSZ cells have been shown to exhibit excellent performance stability over 500hr testing periods when operated reversibly. However, infiltration of a nanocatalyst species, such as GDC10, into the fuel electrode may further improve electrode performance and stability by mitigating Ni coarsening and offering more resilient paths to active reaction sites. In this study, the microstructural degradation of baseline and GDC10-infiltrated RSOC fuel electrodes are quantitatively compared in the context of in-depth electrochemical characterizations. Scanning electron microscopy (SEM) analysis of cell cross sections elucidates the role of GDC10 in improving and stabilizing electrode performance over long-term operation.