scholarly journals Early-Stage Detection of Solid Oxide Cells Anode Degradation by Operando Impedance Analysis

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 848
Author(s):  
Antunes Staffolani ◽  
Arianna Baldinelli ◽  
Linda Barelli ◽  
Gianni Bidini ◽  
Francesco Nobili
Keyword(s):  
Electrochemical Impedance ◽  
Early Stage ◽  
A Priori ◽  
Relaxation Times ◽  
Impedance Analysis ◽  
Solid Oxide ◽  
Hydrogen Energy ◽  
Electrochemical Impedance Spectra ◽  
Ex Post ◽  
Anode Degradation

Solid oxide cells represent one of the most efficient and promising electrochemical technologies for hydrogen energy conversion. Understanding and monitoring degradation is essential for their full development and wide diffusion. Techniques based on electrochemical impedance spectroscopy and distribution of relaxation times of physicochemical processes occurring in solid oxide cells have attracted interest for the operando diagnosis of degradation. This research paper aims to validate the methodology developed by the authors in a previous paper, showing how such a diagnostic tool may be practically implemented. The validation methodology is based on applying an a priori known stress agent to a solid oxide cell operated in laboratory conditions and on the discrete measurement and deconvolution of electrochemical impedance spectra. Finally, experimental evidence obtained from a fully operando approach was counterchecked through ex-post material characterization.

Performance of Ba0.5Sr0.5Co0.8Fe0.2O3-δ-Ag Composite Cathode Materials for IT-SOFCs

2011 ◽  
Vol 311-313 ◽  
pp. 2309-2314 ◽  
Author(s):  
Wen Xia Zhu ◽  
Zhe Lü ◽  
Le Xin Wang ◽  
Xiao Yan Guan ◽  
Xin Yan Zhang
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Electrochemical Impedance ◽  
Composite Cathode ◽  
Solid Oxide ◽  
Electrode Polarization ◽  
Impedance Spectra ◽  
Electrochemical Impedance Spectra ◽  
Composite Cathodes ◽  
Reduced Temperature ◽  
Resistance Value

°Abstract. In order to develop new cathodes for reduced temperature SOFCs, Ba0.5Sr0.5Co0.8Fe0.2O3-δ-Ag composite cathode was investigated in intermediate-temperature Solid Oxide Fuel Cells (IT-SOFCs). The XRD results suggested that no chemical reactions between BSCF and Ag in the composite cathode were found. The resistance measurements showed that the addition of Ag into BSCF improved electrical conductivity of pure BSCF, and the improved conductivity resulted in attractive cathode performance. In addition, electrochemical impedance spectra exhibited the better performance of BSCF-Ag composite cathodes than pure BSCF, e.g., the polarization resistance value of BSCF-Ag was only 0.36Ω cm2 at 650°C, which was nearly 80% lower than that of BSCF electrode. Polarization curves showed the overpotential decreased with the addition of Ag. The current density value of BSCF-Ag was 0.88Acm-2 under –120mV, about five times of that BSCF measured at 650°C. As a summary, compared to a pure BSCF cathode, it was found that adding Ag in the cathode enhanced the BSCF performance significantly.

scholarly journals Application of Promising Electrode Materials in Contact with a Thin-Layer ZrO2-Based Supporting Electrolyte for Solid Oxide Fuel Cells

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1190 ◽  
Author(s):  
Denis A. Osinkin ◽  
Ekaterina P. Antonova ◽  
Alena S. Lesnichyova ◽  
Evgeniy S. Tropin ◽  
Mikhail E. Chernov ◽  
...  
Keyword(s):  
Electrode Materials ◽  
Electrochemical Impedance ◽  
Supporting Electrolyte ◽  
Tape Casting ◽  
Relaxation Times ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Casting Technique ◽  
Triple Layer ◽  
Oxygen Electrodes

The paper presents the results of an investigation into thin single- and triple-layer ZrO2-Sc2O3-based electrolytes prepared using the tape-casting technique in combination with promising electrodes based on La2NiO4+δ and Ni-Ce0.8Sm0.2O2-δ materials. It is shown that pressing and joint sintering of single electrolyte layers allows multilayer structures to be obtained that are free of defects at the layer interface. Electrical conductivity measurements of a triple-layer electrolyte carried out in longitudinal and transverse directions with both direct and alternating current showed resistance of the interface between the layers on the total resistance of the electrolyte to be minimal. Long-term tests have shown that the greatest degradation in resistance over time occurs in the case of an electrolyte with a tetragonal structure. Symmetrical electrochemical cells with electrodes fabricated using a screen-printing method were examined by means of electrochemical impedance spectroscopy. The polarization resistance of the electrodes was 0.45 and 0.16 Ohm∙cm2 at 800 °C for the fuel and oxygen electrodes, respectively. The distribution of relaxation times method was applied for impedance data analysis. During tests of a single solid oxide fuel cell comprising a supporting triple-layer electrolyte having a thickness of 300 microns, a power density of about 160 mW/cm2 at 850 °C was obtained using wet hydrogen as fuel and air as an oxidizing gas.

Sign in / Sign up

Export Citation Format

Share Document