Gas Transport Impedance in Segmented-in-Series Tubular Solid Oxide Fuel Cell

Liu, Bin; Muroyama, Hiroki; Matsui, Toshiaki; Tomida, Kazuo; Kabata, Tatsuo; Eguchi, Koichi

doi:10.1149/1.3519492

Cited by 31 publications

(18 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore fuel variations have a negligible impact on the electrode resistances ASR an and ASR ca compared to the overall resistance ASR tot . This behavior is also representative for other stacks with different cell types at OCV [21,28,29].…”

Section: Conceptual Approachmentioning

confidence: 52%

A model-based approach for current voltage analyses to quantify degradation and fuel distribution in solid oxide fuel cell stacks

Linder

Hocker

Meier

et al. 2015

Journal of Power Sources

View full text Add to dashboard Cite

h i g h l i g h t sIdentification of fuel leakages and fuel distribution in SOFC stacks. Determination of internal resistances from (V,I)-data by eliminating fuel effects. Real-time, model-based identification of malfunctioning of SOFC stacks. Time dependent evolution of degradation phenomena from (V,I)-data. Simulated local species concentrations and current densities along fuel channels. a b s t r a c tReliable quantification and thorough interpretation of the degradation of solid oxide fuel cell (SOFC) stacks under real conditions is critical for the improvement of its long-term stability. The degradation behavior is often analyzed based on the evolution of currentevoltage (V,I) curves. However, these overall resistances often contain unavoidable fluctuations in the fuel gas amount and composition and hence are difficult to interpret. Studying the evolution of internal repeat unit (RU) resistances is a more appropriate measure to assess stack degradation. RU-resistances follow from EIS-data through subtraction of the gas concentration impedance from the overall steady-state resistance. In this work a model-based approach where a local equilibrium model is used for spatial discretization of a SOFC stack RU running on hydrocarbon mixtures such as natural gas. Since under stack operation, fuel leakages, uneven fuel distribution and varying natural gas composition can influence the performance, they are taken into account by the model. The model extracts the time-dependent internal resistance from (V,I)-data and local species concentration without any fitting parameters. RU resistances can be compared with the sum of the resistances of different components that allows one to make links between laboratory degradation experiments and the behavior of SOFC stacks during operation.

show abstract

Section: Conceptual Approachmentioning

confidence: 52%

A model-based approach for current voltage analyses to quantify degradation and fuel distribution in solid oxide fuel cell stacks

Linder

Hocker

Meier

et al. 2015

Journal of Power Sources

View full text Add to dashboard Cite

show abstract

“…They demonstrate for low noise results that are comparable to the use of the lsqnonneg algorithm. Here further results in Figures- [19][20][21][22][23][24] show that robustness holds for increasing noise levels.…”

Section: L-curve and Ncp Parameter Choice Comparisonsmentioning

confidence: 71%

Non-negatively constrained least squares and parameter choice by the residual periodogram for the inversion of electrochemical impedance spectroscopy data

Hansen

Hogue

Sander

et al. 2015

Journal of Computational and Applied Mathematics

View full text Add to dashboard Cite

The inverse problem associated with electrochemical impedance spectroscopy requiring the solution of a Fredholm integral equation of the first kind is considered. If the underlying physical model is not clearly determined, the inverse problem needs to be solved using a regularized linear least squares problem that is obtained from the discretization of the integral equation. For this system, it is shown that the model error can be made negligible by a change of variables and by extending the effective range of quadrature. This change of variables serves as a right preconditioner that significantly improves the condition of the system. Still, to obtain feasible solutions the additional constraint of non-negativity is required. Simulations with artificial, but realistic, data demonstrate that the use of non-negatively constrained least squares with a smoothing norm provides higher quality solutions than those obtained without the non-negative constraint. Using higher-order smoothing norms also reduces the error in the solutions. The L-curve and residual periodogram parameter choice criteria, which are used for parameter choice with regularized linear least squares, are successfully adapted to be used for the non-negatively constrained Tikhonov least squares problem. Although these results have been verified within the context of the analysis of electrochemical impedance spectroscopy, there is no reason to suppose that they would not be relevant within the broader framework of solving Fredholm integral equations for other applications.

show abstract

“…The slurries of the anodes, the anode interlayers, the electrolytes, and the interconnectors were serially screen-printed on the substrate tubes and co-sintered in air at 1400∼1460 • C for 4 h. Afterward, the slurries of the cathode active layers and cathode current collecting layers were serially screen-printed on the aforementioned cosintering assemble and subsequently baked in air at 1300∼1365 • C for 2 h. Details of the textual parameters of a single cell are described in Ref. 16. The dimensions of the cell components have been designed so as to be suitable for the basic electrochemical evaluation.…”

Section: Methodsmentioning

confidence: 99%

“…The test apparatus can be seen in Ref. 16. All the electrochemical tests were carried out on cell 1.…”

Section: Methodsmentioning

confidence: 99%

Dynamic Behavior of Segmented-in-Series Tubular Solid Oxide Fuel Cell upon Discharge

Liu

Muroyama

Matsui

et al. 2012

J. Electrochem. Soc.

Self Cite

View full text Add to dashboard Cite

Dynamic behavior of the segmented-in-series tubular solid oxide fuel cell upon discharge was investigated. The cell performance decreased initially at 900 • C, accompanied by the increase of ohmic resistance. Lower partial pressure of oxygen in the cathode resulted in a more severe decrease, whereas the gas displacement in the anode compartment did not induce such behavior. As the current was cut off, the ohmic resistance rapidly recovered toward the starting value before current load. The possible origin for this increase-recovery behavior of the ohmic resistance has been discussed based on the evaluation of oxygen partial pressure at the cathode/electrolyte interface and element interdiffusion between cathode and electrolyte.) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 130.54.130.250 Downloaded on 2014-08-27 to IP Journal of The Electrochemical Society, 159 (3) B324-B330 (2012) B325 ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 130.54.130.250 Downloaded on 2014-08-27 to IP Journal of The Electrochemical Society, 159 (3) B324-B330 (2012) B327 0.22 A cm -2 0 A cm -2 ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 130.54.130.250 Downloaded on 2014-08-27 to IP

show abstract

Gas Transport Impedance in Segmented-in-Series Tubular Solid Oxide Fuel Cell

Cited by 31 publications

References 33 publications

A model-based approach for current voltage analyses to quantify degradation and fuel distribution in solid oxide fuel cell stacks

A model-based approach for current voltage analyses to quantify degradation and fuel distribution in solid oxide fuel cell stacks

Non-negatively constrained least squares and parameter choice by the residual periodogram for the inversion of electrochemical impedance spectroscopy data

Dynamic Behavior of Segmented-in-Series Tubular Solid Oxide Fuel Cell upon Discharge

Contact Info

Product

Resources

About