Femtosecond Laser-Induced Surface Modification of the Electrolyte in Solid Oxide Electrolysis Cells

Abstract

Electrolyte-supported solid oxide cells are often used for steam electrolysis. Advantages are high mechanical stability and a low degradation rate. The aim of this proof of concept study was to use a femtosecond laser to process the electrolyte of an electrolyte-supported solid oxide cell and evaluate the effect of this laser treatment on the electrochemical performance. The femtosecond laser treatment induces a macroscopic and a superimposed microscopic structure. It can be proven that the electrolyte remains gas tight and the electrochemical performance increases independently of the laser parameters. The initial area-specific resistance degradation during a constant current measurement of 200 h was reduced from 7.9% for a non-treated reference cell to 3.2% for one of the laser-treated cells. Based on electrochemical impedance measurements, it was found that the high frequency resistance of the laser-treated cells was reduced by up to 20% with respect to the reference cell. The impedance spectra were evaluated by calculating the distribution of relaxation times, and in advance, a novel approach was used to approximate the gas concentration resistance, which was related to the test setup and not to the cell. It was found that the low frequency polarization resistance was increased for the laser-treated cells. In total, the area-specific resistance of the laser-treated cells was reduced by up to 14%.

Laser Machining of Nickel Oxide–Yttria Stabilized Zirconia Composite for Surface Modification in Solid Oxide Fuel Cells

“…Accordingly, laser parameters selected for the processing of laser tracks were at 4.3 J/cm 2 and 1.0 kHz, thus obtaining a valley depth close to 2 µm with a roughness lower than 0.20 µm and a minimized pile-up size. This laser track presented a valley depth smaller than that required for a remarkable modification of the electrode-electrolyte interface in an anode-supported SOFC, as the valley typically presents from a few to tens of micrometers [32][33][34][35][36][37][38][39][40][41]58]. Therefore, it is assumed that this laser track was satisfactory for subsequent studies related to microstructure and phase changes, and chemical and mechanical tests.…”

“…The extension of material pile-up mainly depends on the accuracy of the laser. Compared with pico-or femtosecond lasers, the accuracy of our laser is much lower, which also generates a wider laser track [58]. On the other hand, laser machining produces splashes of redeposited material and cracks, which generates significant roughness along the valley and pile-up surfaces.…”

“…Furthermore, the presence of this roughness may enhance the electrode and electrolyte adhesion. The specific goal of this work was to reproduce laser tracks within the typical range of energy density (3.3-6.4 J/cm 2 ) [31,49,58] for SOFC materials with good surface quality to analyze the damage and possible microstructure changes. Accordingly, laser parameters selected for the processing of laser tracks were at 4.3 J/cm 2 and 1.0 kHz, thus obtaining a valley depth close to 2 µm with a roughness lower than 0.20 µm and a minimized pile-up size.…”

Electrochemical Carbon Dioxide Reduction on Femtosecond Laser-Processed Copper Electrodes: Effect on the Liquid Products by Structuring and Doping

“…To assess the role of these parameters, we structure copper electrodes through femtosecond laser (fs-laser) irradiation. , Laser-induced surface structures can be tuned from tens of nanometer to 100 μm . The enhanced surface structures have been proved beneficial in electrocatalytic reactions, especially in electrolysis technologies. − Although it is an ablation process, elements from the femtosecond laser process environment are incorporated. , Therefore, additional features are enabled, such as hyperdoping , or an increased catalytic activity due to further added catalyst elements, thus allowing us to assess the role of dopants on the CO 2 RR selectivity.…”

Comparative Analysis of Loss Mechanism Localization in a Semi-2D SOEC Single Cell Modell: Non-Equilibrium Thermodynamics versus Monocausal-Based Approach

“…Additional details pertaining to the experimental configuration and the measurement methodology can be found in Ref. 38. To ensure a direct comparison of the U, j-characteristic curves, the same conditions were selected in the experiment as for Kerafol, cf.…”