10.26165/JUELICH-DATA/6RNQAR Wolf, Stephanie E.0000-0002-9627-7121(IET-1 Forschungszentrum Jülich, IPC RWTH Aachen)Vibhu, Vaibhav0000-0001-9157-2722(IET-1 Forschungszentrum Jülich)Chakraborty, Pritam0000-0001-8237-3828(IET-1 Forschungszentrum Jülich, IPC RWTH Aachen)Coll, Carla L.(IET-1 Forschungszentrum Jülich)Schönert, Sandro0000-0001-6591-9462(IET-1 Forschungszentrum Jülich, IPC RWTH Aachen)Basak, Shibabrata0000-0002-4331-4742(IET-1 Forschungszentrum Jülich)Vinke, Izaak C.0000-0002-1361-9983(IET-1 Forschungszentrum Jülich)de Haart, L.G.J. (Bert)0000-0001-6908-1214(IET-1 Forschungszentrum Jülich)Eichel, Rüdiger-A.0000-0002-0013-6325(IET-1 Forschungszentrum Jülich, IPC RWTH Aachen) Jülich DATA 2025 This data repository contains the data sets associated with the manuscript 'Electrochemical Performance and Durability of High-Temperature Solid Oxide Electrolysis Cells with SFM and SFM-GDC Fuel Electrodes for Hydrogen and Syngas Production'. Published in J. Mater. Chem. A link Motivation: The increasing need to valorize emitted CO2 and close the carbon cycle through the production of synthesis gas, fuel, and hydrogen has driven the development of high-temperature electrolysis technology. SOEC offers a promising solution with its ability to produce pure H2 at elevated temperatures (650°C-900°C) without the use of precious metal catalysts, making it cost-effective and more efficient than low-temperature technologies like alkaline and polymer exchange membrane cells due to advantageous kinetics and thermodynamics. By utilizing pre-existing chemical industry heat, SOEC can achieve high electrical efficiencies of up to 100%. The long-term stability and performance of current Ni-based fuel electrodes is preventing the wide industrial implementation though, prompting the search for alternative Ni-free materials with good electrochemical performance and long-term stability, such as perovskite fuel electrodes like Sr2FeMoO6-δ (SFM). Central Research Question: In this work, solid oxide electrolysis cells with SFM and the composite ceramic-ceramic (cercer) SFM-GDC fuel electrode materials were investigated in steam- and co-electrolysis conditions for the first time, regarding performance and long-term stability of up to 500 h in 50% steam and 50% H2. Description of folder contents (switch to tree view): 01_In Situ Transmission Electron Microscopy: Contains the taken TEM Images taken and the experimental procedure. 02_X-Ray Diffraction_Temperature_Atmosphere Variation: Contains raw data files of the XRD measurements, the TOPAS6 fit criteria, the Rietveld Report as well as the data over the whole in operando Experiment. 03_X-Ray Photoelectron Spectroscopy: Contains the raw data and the data evalution for the measurements in air and after reduction in H2. 04_Powder_Scanning Electron Microscopy: Contains the SEM Image of the unreduced and reduced sample. 05_Conductivity Measurement: Contains the raw data for SFM and SFM-GDC conductivty measurements in air and in H2. 06_Transmission Electron Microscopy: Contains the Image of one exsoluted nanoparticle observed for SFM. 07_Electrochemistry_Initial Performance Characterization: Contains the raw data of the initial AC and DC characterization of the cells with an SFM and an SFM-GDC fuel electrode. The data are seperated by the operating gas atmospheres for steam electrolysis (50%H2O + 50%H2) and co-electrolysis (40%H2O + 40% CO2 + 20%H2) and then subdivided regarding the varied Parameter (Temperature, Polarization, Partial Pressure Variations). 08_Electrochemistry_ResistancePlots: Contains the evaluation data of the electrochemical impedance measurements for SFM and SFM-GDC. 09_Electrochemistry_Degradation_Testing: Contains the raw data of the electrochemical Degradation testing for SFM and SFM-GDC. 10_Posttest Scanning Electron Microscopy: Contains the SEM-EDS Images of the post-test characterized single cells regarding oxygen and fuel electrodes in comparison to pristine cell microstructure. 11_Dilatometry: Contains raw data of dilatometry measurements to analyse the thermal Expansion coefficient of SFM and SFM-GDC in air. List of abbreviations : AC - Alternating Current DC - Direct Current FE - Fuel Electrode OE - Oxygen Electrode SEM - Scanning Electron Microscopy EDS - Energy-Dispersive X-ray Spectroscopy OCV - Open Circuit Voltage Vibhu, Vaibhav(IET-1)Eichel, Rüdiger-A.(IET-1)