Influence of Electrode Design and Contacting Layers on Performance of Electrolyte Supported SOFC/SOEC Single Cells

Abstract

The solid oxide cell is a basis for highly efficient and reversible electrochemical energy conversion. A single cell based on a planar electrolyte substrate as support (ESC) is often utilized for SOFC/SOEC stack manufacturing and fulfills necessary requirements for application in small, medium and large scale fuel cell and electrolysis systems. Thickness of the electrolyte substrate, and its ionic conductivity limits the power density of the ESC. To improve the performance of this cell type in SOFC/SOEC mode, alternative fuel electrodes, on the basis of Ni/CGO as well as electrolytes with reduced thickness, have been applied. Furthermore, different interlayers on the air side have been tested to avoid the electrode delamination and to reduce the cell degradation in electrolysis mode. Finally, the influence of the contacting layer on cell performance, especially for cells with an ultrathin electrolyte and thin electrode layers, has been investigated. It has been found that Ni/CGO outperform traditional Ni/8YSZ electrodes and the introduction of a ScSZ interlayer substantially reduces the degradation rate of ESC in electrolysis mode. Furthermore, it was demonstrated that, for thin electrodes, the application of contacting layers with good conductivity and adhesion to current collectors improves performance significantly.

Electrochemical Impedance Analysis of Ni/CGO10-Based Electrolyte-Supported Cells

“…However, this approach has been proven to be more difficult for Ni/CGO10-based cells due to the occurrence of a low frequency electrode process at ~1 Hz, and therefore the convolution of anode, cathode, and mass transport contributions with similar relaxation frequencies (2,12). This low frequency process was attributed to a surface process, most likely the electrode charge transfer reaction (12).…”

Investigation of solid oxide fuel cell operation with synthetic biomass gasification product gases as a basis for enhancing its performance

“…The cell consisted of a 40 μm Ni/GDC anode, a 45 μm lanthanum strontium manganite (LSM) cathode and a 165 μm scandia stabilized zirconia (SSZ) electrolyte. A detailed description of the cell structure and materials can be found in [45] as well as in [46]. The cell was placed in an alumina housing developed in-house with nickel and platinum meshes used for the electrical contacting of anode and cathode, respectively.…”

Novel Composite Electrolytes of Zr0.92Y0.08O2-α(8YSZ)-Low Melting Point Glass Powder for Intermediate Temperature Solid Oxide Fuel Cells

“…The result is lower than that previous reported cathode supported thin film fuel cell with 200–400 mW·cm −2 at 800–850 °C [12,13,14,30], which can be attributed to the electrolyte thickness and the electrode/electrolyte interface. Further work is in progress to optimize the composition of composite electrolytes and develop the stable and high performance solid oxide fuel cell [31,32]. …”