A Comparative Study Between Resistance Measurements in Model Experiments and Solid Oxide Fuel Cell Stack Performance Tests

2006 ◽  
Vol 4 (1) ◽  
pp. 11-18 ◽  
Author(s):  
V. A. C. Haanappel ◽  
P. Batfalsky ◽  
S. M. Gross ◽  
L. G. J. de Haart ◽  
J. Malzbender ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Electrochemical Performance ◽  
Solid Oxide Fuel Cell ◽  
Glass Ceramic ◽  
Solid Oxide ◽  
Constant Current ◽  
Oxide Fuel ◽  
Chemical Interactions ◽  
Model Experiments ◽  
Sofc Stacks

Several combinations of glass-ceramic and steel compositions with excellent chemical and physical properties have been tested in the past in solid oxide fuel cell (SOFC) stacks, but there have also been some combinations exhibiting pronounced chemical interactions causing severe stack degradation. Parallel to the examination of these degradation and short-circuiting phenomena in stack tests, recently less complex model experiments have been developed to study the interaction of glass-ceramic sealants and interconnect steels. The sealants and steels were tested in the model experiments at operation temperature using a dual air/hydrogen atmosphere similar to stack conditions. The present work compares electrochemical performance under constant current load of SOFC stack tests with the resistance changes in model experiments. In addition, microstructural results of post-operation inspection of various sealant–steel combinations are presented. The model experiments have shown that under the chosen experimental conditions, distinct changes of the specific resistance of the specimens correlate well with the changes of the electrochemical performance of SOFC stacks, indicating that this method can be considered as an excellent comparative method to provide useful information on the physical and chemical interactions between glass-ceramic sealants and ferritic steels.

Tolerance Tests of Co-Feeding Cl2 and H2S Impurities in Biogas on a Ni-YSZ Anode-Supported Solid Oxide Fuel Cell

2010 ◽  
Author(s):  
Chunchuan Xu ◽  
John W. Zondlo ◽  
Mingyang Gong ◽  
Xingbo Liu ◽  
I. B. Celik
Keyword(s):  
Fuel Cell ◽  
Electrochemical Performance ◽  
Solid Oxide Fuel Cell ◽  
Cost Effective ◽  
Renewable Resource ◽  
Solid Oxide ◽  
Constant Current ◽  
Oxide Fuel ◽  
Trace Impurities ◽  
Fuel Gas

Biogas is a renewable resource which comes from numerous sources, such as biomass, manure, sewage, municipal waste, green waste and energy crops. It is a variable mixture of CH4, CO2, N2 and other gases. Ni-YSZ cermet is commonly used as the anode of a solid oxide fuel cell (SOFC) because it has excellent electrochemical performance and is cost effective. It can utilize not only hydrogen fuel, but also a clean synthesized biogas mixture of varying CH4 and CO2 concentrations with steam (H2O) and air (O2). However, trace impurities, such as H2S, Cl2, and F2 in biogas may cause degradation of cell performance. In this work, Ni-CeO2 coated Ni-YSZ anode-supported cells were exposed to two different compositions of synthesized biogases (biogas) with 100 ppm Cl2 under a constant current load at 850°C. The electrochemical performance was evaluated periodically using standard electrochemical methods. 20 ppm H2S impurity was also added to the fuel stream during the Cl2 impurity testing and its effect was noted. Post-mortem analyses of the SOFC anode were performed using XRD, SEM and XPS. The results show that Cl2 did not cause any electrochemical degradation of the cell during the 200 h test. However, after adding 20 ppm H2S, the cell started to degrade and eventually lost all its performance. The experimental data showed that 100 ppm Cl2 impurity in the fuel gas can postpone the degradation caused by addition of the H2S impurity.

Determination of the interfacial fracture energies of cathodes and glass ceramic sealants in a planar solid-oxide fuel cell design

2003 ◽  
Vol 18 (4) ◽  
pp. 929-934 ◽  
Author(s):  
Jürgen Malzbender ◽  
Rolf W. Steinbrech ◽  
Lorenz Singheiser
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Fracture Energy ◽  
Glass Ceramic ◽  
Current Collector ◽  
Interfacial Fracture ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Composite Cathodes ◽  
Sofc Stacks

A notched bimaterial bar bend test was applied to identify weak interfaces that influence the thermomechanical performance of solid-oxide fuel cell (SOFC) stacks with planar design. The experiments were focused on the weakest interface of the multilayered cells and on the rigid glass ceramic sealants between metallic interconnects of SOFC stacks. The fracture energies of these interfaces were determined. To test interfaces within the cells, they were glued to steel strips, and the notched cell was used as a stiffener in the test. The weakest part of the cells with composite cathodes was the interface between the functional part of the cathode and the remaining current collector. Values for the interfacial fracture energies of composite cathodes both freshly prepared and after aging were determined. Taking advantage of the crack extension within the anode from the notch-tip to the interface, the fracture energy of the oxidized and reduced anodes was calculated. Sandwich specimens with glass ceramic between the interconnect steel were used to determine the fracture energies for different glass ceramic–steel interfaces. Different combinations of ferritic steel and glass ceramic were tested. The fracture path developed partly along the interface and partly in the glass ceramic, which did not influence the fracture energy. However, a significant improvement of the fracture energy with annealing time was found.

Phase Inversion Tape Casting and Electrochemical Performance of Solid Oxide Fuel Cell Anode

2015 ◽  
Vol 30 (12) ◽  
pp. 1291
Author(s):  
ZHANG Yu-Yue ◽  
LIN Jie ◽  
MIAO Guo-Shuan ◽  
GAO Jian-Feng ◽  
CHEN Chu-Sheng ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Electrochemical Performance ◽  
Solid Oxide Fuel Cell ◽  
Phase Inversion ◽  
Tape Casting ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Cell Anode ◽  
Fuel Cell Anode

A high performance ceria-based solid oxide fuel cell operating on underground coal gasification gas

RSC Advances ◽  
2015 ◽  
Vol 5 (106) ◽  
pp. 87477-87483 ◽  
Author(s):  
Jie Xiong ◽  
Chengran Jiao ◽  
Minfang Han ◽  
Wentao Yi ◽  
Jie Ma ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Electrochemical Performance ◽  
Solid Oxide Fuel Cell ◽  
High Performance ◽  
Coal Gasification ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Underground Coal Gasification ◽  
Long Term Stability

A NiO-GDC‖GDC‖Ba0.9Co0.7Fe0.2Nb0.1O3−δ cell fed with UCG gas demonstrated exceptional electrochemical performance and desirable long term stability.

Investigation on the Performance and Durability Behavior for the Anode-Supported Solid Oxide Fuel Cell with Composite Cathodes

2019 ◽  
Vol 962 ◽  
pp. 101-111
Author(s):  
Tai Nan Lin ◽  
Yang Chuang Chang ◽  
Maw Chwain Lee ◽  
Wei Xin Kao
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Solid Oxide ◽  
Cell Performance ◽  
Constant Current ◽  
External Loading ◽  
Testing Time ◽  
Oxide Fuel ◽  
Transfer Resistance ◽  
Composite Cathodes

The anode-supported solid oxide fuel cell (SOFC) comprises of NiO-8YSZ | 8YSZ | LSM-GDC | LSCF and the performance durability is executed for over 1000 hours. It shows low degradation phenomena under constant current operation during the complete testing period. The cell performance decreases with the decreasing of the temperature, and the maximum power densities are 408, 265, and 163 mW cm-2at 800, 750, and 700 °C, respectively. According to the EIS analysis with the equivalent circuit model of five serial components, all resistances decrease with the testing time except the non-charge transfer resistance of the cathode. However all resistances increase with the decreasing of the temperature on the contrary. The ohmic resistance of the cell (RO) dominates the cell performance under the whole durability test period as well as the operation temperature. In this study, the ROis determined by the interfacial contact resistances, which occurred between the cell and the connecting components. The LSM-GDC | LSCF interfaces formed the discontinuous gap due to the weak attachment and external loading. The result of the activation energy analysis shows that the rate-determination step of the cell is existed in the anode side between 700 and 800 °C. However, the cell performance is controlled from the domination of the ROat 800 °C shift to the joint contributions of the RO, anodic polarization (RAP), and cathodic polarization (RCP) at 700 °C.

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