A technical report on the surface-energy and morphology-based screening for electrode/electrolyte interface compatibility in SOFC/ReSOC materials

Abstract

The performance and durability of solid oxide fuel cells and reversible solid oxide cells are strongly affected by the electrode-electrolyte interface, where charge transfer, ionic transport, adhesion, morphology and thermomechanical stability interact. Early-stage compatibility screening is usually based on electrochemical or compositional criteria, whereas surface-related descriptors are rarely included in a unified framework. This work proposes a surface-based methodology to assess the expected compatibility of candidate electrode-electrolyte pairings. Contact-angle measurements with water and glycerol are used to determine total, dispersive and polar surface free energy components through the Owens-Wendt-Rabel-Kaelble method. Confocal topography is used to extract ISO 25178 roughness parameters, including average roughness, peak-to-valley height, valley depth, skewness, kurtosis and surface slope. A compatibility matrix is constructed by combining energetic affinity and morphological suitability, with emphasis on the electrolyte surface, since the electrode is deposited directly onto the electrolyte substrate. The results indicate that the most promising interfaces are not necessarily those with the highest surface free energy, but those combining high adhesion work, low interfacial energy and a substrate morphology suitable for continuous electrode deposition. The proposed approach provides a rational pre-electrochemical screening tool to prioritize electrode-electrolyte combinations for subsequent validation by electrochemical impedance spectroscopy, area specific resistance, electrical contact resistance, microstructural analysis and durability testing. Although it does not replace electrochemical characterization, it offers a physically grounded way to connect surface chemistry, topography and interface formation in solid oxide cell materials.