scholarly journals Microstructure Evolution in a Solid Oxide Fuel Cell Stack Quantified with Interfacial Free Energy

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3476
Author(s):  
Tomasz A. Prokop ◽  
Grzegorz Brus ◽  
Janusz S. Szmyd
Keyword(s):  
Free Energy ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Microstructure Evolution ◽  
Ion Beam ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Long Term Performance ◽  
Term Performance

Degradation of electrode microstructure is one of the key factors affecting long term performance of Solid Oxide Fuel Cell systems. Evolution of a multiphase system can be described quantitatively by the change in its interfacial energy. In this paper, we discuss free energy of a microstructure to showcase the anisotropy of its evolution during a long-term performance experiment involving an SOFC stack. Ginzburg Landau type functional is used to compute the free energy, using diffuse phase distributions based on Focused Ion Beam Scanning Electron Microscopy images of samples taken from nine different sites within the stack. It is shown that the rate of microstructure evolution differs depending on the position within the stack, similar to phase anisotropy. However, the computed spatial relation does not correlate with the observed distribution of temperature.

Analysis of Long-Term and Thermal Cycling Tests for a Commercial Solid Oxide Fuel Cell

2017 ◽  
Vol 14 (4) ◽  
Author(s):  
Dustin Lee ◽  
Jing-Kai Lin ◽  
Chun-Huang Tsai ◽  
Szu-Han Wu ◽  
Yung-Neng Cheng ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Thermal Cycling ◽  
Solid Oxide Fuel Cell ◽  
Coefficient Of Thermal Expansion ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Flow Rates ◽  
Degradation Rates ◽  
Two Stages

The effects of isothermally long-term and thermal cycling tests on the performance of an ASC type commercial solid oxide fuel cell (SOFC) have been investigated. For the long-term test, the cells were tested over 5000 h in two stages, the first 3000 h and the followed 2000 h, under the different flow rates of hydrogen and air. Regarding the thermal cycling test, 60 cycles in total were also divided into two sections, the temperature ranges of 700 °C to 250 °C and 700 °C to 50 °C were applied for the every single cycle of first 30 cycles and the later 30 cycles, respectively. The results of long-term test show that the average degradation rates for the cell in the first 3000 h and the followed 2000 h under different flow rates of fuel and air are 1.16 and 2.64%/kh, respectively. However, there is only a degradation of 6.6% in voltage for the cell after 60 thermal cycling tests. In addition, it is found that many pores formed in the anode of the cell which caused by the agglomeration of Ni after long-term test. In contrast, the vertical cracks penetrating through the cathode of the cell and the in-plane cracks between the cathode and barrier layer of the cell formed due to the coefficient of thermal expansion (CTE) mismatch after 60 thermal cycling tests.

Coke-free operation of an all porous solid oxide fuel cell (AP-SOFC) used as an O2 supply device

2015 ◽  
Vol 3 (6) ◽  
pp. 2684-2689 ◽  
Author(s):  
Y. M. Guo ◽  
G. Largiller ◽  
C. Guizard ◽  
C. Tardivat ◽  
D. Farrusseng
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Coke Formation ◽  
Solid Oxide ◽  
Operational Stability ◽  
Porous Solid ◽  
Cell Performance ◽  
Oxide Fuel ◽  
O2 Supply

An anode-supported AP-SOFC with long-term operational stability was developed to improve cell performance over 14 times without any coke formation.

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.

Post-Operational Characterization of a Long-Term Operated Solid Oxide Fuel Cell Stack

2021 ◽  
Vol 103 (1) ◽  
pp. 1047-1058
Author(s):  
Norbert Menzler ◽  
Doris Sebold ◽  
Sebastian Zischke ◽  
Joanna Zurek ◽  
Dmitry Naumenko ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Fuel Cell Stack

scholarly journals A Multiscale Approach to the Numerical Simulation of the Solid Oxide Fuel Cell

Catalysts ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 253 ◽  
Author(s):  
Marcin Mozdzierz ◽  
Katarzyna Berent ◽  
Shinji Kimijima ◽  
Janusz S. Szmyd ◽  
Grzegorz Brus
Keyword(s):  
Experimental Data ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Multiscale Model ◽  
Solid Oxide ◽  
Correct Prediction ◽  
Multiscale Approach ◽  
Oxide Fuel

The models of solid oxide fuel cells (SOFCs), which are available in the open literature,may be categorized into two non-overlapping groups: microscale or macroscale. Recent progressin computational power makes it possible to formulate a model which combines both approaches,the so-called multiscale model. The novelty of this modeling approach lies in the combination ofthe microscale description of the transport phenomena and electrochemical reactions’ with thecomputational fluid dynamics model of the heat and mass transfer in an SOFC. In this work,the mathematical model of a solid oxide fuel cell which takes into account the averaged microstructureparameters of electrodes is developed and tested. To gain experimental data, which are used toconfirm the proposed model, the electrochemical tests and the direct observation of the microstructurewith the use of the focused ion beam combined with the scanning electron microscope technique(FIB-SEM) were conducted. The numerical results are compared with the experimental data fromthe short stack examination and a fair agreement is found, which shows that the proposed modelcan predict the cell behavior accurately. The mechanism of the power generation inside the SOFC isdiscussed and it is found that the current is produced primarily near the electrolyte–electrode interface.Simulations with an artificially changed microstructure does not lead to the correct prediction of thecell characteristics, which indicates that the microstructure is a crucial factor in the solid oxide fuelcell modeling.

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