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

Author(s):  
Dustin Lee ◽  
Jing-Kai Lin ◽  
Chun-Huang Tsai ◽  
Szu-Han Wu ◽  
Yung-Neng Cheng ◽  
...  

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.

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3476
Author(s):  
Tomasz A. Prokop ◽  
Grzegorz Brus ◽  
Janusz S. Szmyd

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.


2015 ◽  
Vol 3 (6) ◽  
pp. 2684-2689 ◽  
Author(s):  
Y. M. Guo ◽  
G. Largiller ◽  
C. Guizard ◽  
C. Tardivat ◽  
D. Farrusseng

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


Author(s):  
Cun Wang ◽  
Tao Zhang ◽  
Cheng Zhao ◽  
Jian Pu

A three dimensional numerical model of a practical planar solid oxide fuel cell (SOFC) stack based on the finite element method is constructed to analyze the thermal stress generated at different uniform temperatures. Effects of cell positions, different compressive loads, and coefficient of thermal expansion (CTE) mismatch of different SOFC components on the thermal stress distribution are investigated in this work. Numerical results indicate that the maximum thermal stress appears at the corner of the interface between ceramic sealants and cells. Meanwhile the maximum thermal stress at high temperature is significantly larger than that at room temperature (RT) and presents linear growth with the increase of operating temperature. Since the SOFC stack is under the combined action of mechanical and thermal loads, the distribution of thermal stress in the components such as interconnects and ceramic sealants are greatly controlled by the CTE mismatch and scarcely influenced by the compressive loads.


RSC Advances ◽  
2015 ◽  
Vol 5 (106) ◽  
pp. 87477-87483 ◽  
Author(s):  
Jie Xiong ◽  
Chengran Jiao ◽  
Minfang Han ◽  
Wentao Yi ◽  
Jie Ma ◽  
...  

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


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

2005 ◽  
Author(s):  
Comas L. Haynes ◽  
J. Chris Ford

During latter-stage, “start-up” heating of a solid oxide fuel cell (SOFC) stack to a desired operating temperature, heat may be generated in an accelerating manner during the establishment of electrochemical reactions. This is because a temperature rise in the stack causes an acceleration of electrochemical transport given the typical Arrhenius nature of the electrolyte conductivity. Considering a potentiostatic condition (i.e., prescribed cell potential), symbiosis thus occurs because greater current prevalently leads to greater by-product heat generation, and vice versa. This interplay of the increasing heat generation and electrochemistry is termed “light off”, and an initial model has been developed to characterize this important thermal cycling phenomenon. The results of the simulation begin elucidating the prospect of using cell potential as well as other electrochemical operating conditions (e.g., reactants utilization) as dynamic controls in managing light off transients and possibly mitigating thermal cycling issues.


Author(s):  
Fatma N. Cayan ◽  
Suryanarayana R. Pakalapati ◽  
Francisco Elizalde-Blancas ◽  
Ismail Celik

A new phenomenological one-dimensional model is formulated to simulate the typical degradation patterns observed in Solid Oxide Fuel Cell (SOFC) anodes due to coal syngas contaminants such as arsenic (As) and phosphorous (P). The model includes ordinary gas phase diffusion including Knudsen diffusion and surface diffusion within the anode and the adsorption reactions on the surface of the Ni-YSZ based anode. Model parameters such as reaction rate constants for the adsorption reactions are calibrated to match the degradation rates reported in the literature. Preliminary results from implementation of the model demonstrated that the deposition of the impurity on the Ni catalyst starts near the fuel channel/anode interface and slowly moves toward the active anode/electrolyte interface which is in good agreement with the experimental data. Parametric studies performed at different impurity concentrations, operating temperatures and current densities showed that the coverage rate increases with increasing temperature, impurity concentration and current density, as expected.


Sign in / Sign up

Export Citation Format

Share Document