The effect of water content on the electrochemical impedance response and microstructure of Ni-CGO anodes for solid oxide fuel cells

2009 ◽  
Vol 189 (2) ◽  
pp. 1060-1065 ◽  
Author(s):  
P. Kim ◽  
D.J.L. Brett ◽  
N.P. Brandon
2015 ◽  
Vol 69 (16) ◽  
pp. 39-48 ◽  
Author(s):  
N. Yang ◽  
E. Strelcov ◽  
A. Belianinov ◽  
A. Tebano ◽  
V. Foglietti ◽  
...  

Author(s):  
Seung-Wook Baek ◽  
Joongmyeon Bae

Samarium (Sm) is a rare earth material that shows promise for use in cathodes of intermediate temperature-operating solid oxide fuel cells (IT-SOFCs). Perovskite-structured oxide containing Sm has very attractive electrocatalytic properties, and spinel-structured oxide generally exhibits low thermal expansion, indicating its suitability for application as a SOFC cathode. In this paper, the characteristics of the various Sm-based oxide materials (Sm-Sr-(Co,Fe,Ni)-O) deposited on Sm0.2Ce0.8O1.9 (SDC) electrolyte pellets were investigated in terms of their microstructure, sinterability and electrochemical properties. The relationship between the composition and the sintering temperature was studied and discussed. Results show that the substitution of iron (Fe) and nickel (Ni) in Co-sites affects the sinterability, adhesion to the electrolyte and electrochemical activity, such that the different sintering temperatures for these compositions should be considered. The microstructure and sinterability of the cathodes were investigated using a scanning electron microscope (SEM). Area specific resistance (ASR) values for all cathode compositions were measured using AC electrochemical impedance spectroscopy (EIS).


2012 ◽  
Vol 727-728 ◽  
pp. 769-774
Author(s):  
A. Ávila ◽  
J. Poveda ◽  
D. Gómez ◽  
D. Hotza ◽  
J. Escobar

Solid oxide fuel cells (SOFCs) have emerged as an efficient way to transform chemical energy into electrical energy. However, a major disadvantage of this technology is related to the high temperatures required for SOFC operation. In this way, new materials are necessary to maintain the electrical properties of the cell at intermediate temperatures. Based on these ideas, it is necessary to study both the structural variation of the cells components at different temperatures and their electrochemical behavior. In this work, a crystallographic characterization is presented, which was performed in a commercial SOFC cell using X-ray diffraction (XRD). An equivalent linear electrical model to predict SOFC losses is developed as well. Keywords: Solid oxide fuel cells (SOFCs); AC impedance; Electrochemical impedance spectroscopy (EIS); Equivalent circuit models.


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4702
Author(s):  
Roberto Spotorno ◽  
Marlena Ostrowska ◽  
Simona Delsante ◽  
Ulf Dahlmann ◽  
Paolo Piccardo

A commercially available glass-ceramic composition is applied on a ferritic stainless steel (FSS) substrate reproducing a type of interface present in solid oxide fuel cells (SOFCs) stacks. Electrochemical impedance spectroscopy (EIS) is used to study the electrical response of the assembly in the temperature range of 380–780 °C and during aging for 250 h at 780 °C. Post-experiment analyses, performed by means of X-ray diffraction (XRD), and along cross-sections by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis, highlight the microstructural changes promoted by aging conditions over time. In particular, progressive crystallization of the glass-ceramic, high temperature corrosion of the substrate and diffusion of Fe and Cr ions from the FSS substrate into the sealant influence the electrical response of the system under investigation. The electrical measurements show an increase in conductivity to 5 × 10−6 S∙cm−1, more than one order of magnitude below the maximum recommended value.


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