Fuel Cell and Electrolysis Mode Results for BCY SOFC Compared with Model Predictions

2012 ◽  
Keyword(s):  
Fuel Cell ◽  
Model Predictions ◽  
Electrolysis Mode

Investigation of Transport Phenomena in Micro Flow Channels for Miniature Fuel Cells

2003 ◽  
Author(s):  
S. W. Cha ◽  
S. J. Lee ◽  
Y. I. Park ◽  
F. B. Prinz
Keyword(s):  
Fuel Cell ◽  
Power Density ◽  
Peak Power ◽  
Gas Flow ◽  
Transport Phenomena ◽  
Cell Performance ◽  
Peak Power Density ◽  
Micro Channels ◽  
Model Predictions ◽  
The Impact

This paper presents a study on the transport phenomena related to gas flow through fuel cell micro-channels, specifically the impact of dimensional scale on the order of 100 microns and below. Especially critical is the ability to experimentally verify model predictions, and this is made efficiently possible by the use of structural photopolymer (SU-8) to directly fabricate functional fuel cell micro-channels. The design and analysis components of this investigation apply 3-D multi-physics modeling to predict cell performance under micro-channel conditions. Interestingly, the model predicts that very small channels (specifically 100 microns and below) result in a significantly higher peak power density than larger counterparts. SU-8 micro-channels with different feature sizes have been integrated into fuel cell prototypes and tested for comparison against model predictions. The results not only demonstrate that the SU-8 channels with metal current collector show quite appreciable performance, but also provide experimental verification of the merits of channel miniaturization. As predicted, the performance in terms of peak power density increases as the feature size of the channel decreases, even though the pressure drop is higher in the more narrow channels. So it has been observed both theoretically and experimentally that cell performance shows an improving trend with micro-channels, and design optimization for miniature fuel cell provides a powerful method for increasing power density.

Degradation Mechanism of Oxygen Electrode Under Fuel-Cell and Electrolysis Mode Operations

2019 ◽  
Vol 91 (1) ◽  
pp. 681-685
Author(s):  
Jong-Ho Lee ◽  
Ho Il Ji ◽  
Sanghyeok Lee ◽  
Ji-Su Kim ◽  
Sung Min Choi ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Degradation Mechanism ◽  
Oxygen Electrode ◽  
Electrolysis Mode

scholarly journals Performance Assessment of Single Electrode-Supported Solid Oxide Cells Operating in the Steam Electrolysis Mode

2011 ◽  
Author(s):  
X. Zhang ◽  
J. E. O’Brien ◽  
R. C. O’Brien ◽  
N. Petigny
Keyword(s):  
Fuel Cell ◽  
Single Cells ◽  
Operating Conditions ◽  
Solid Oxide ◽  
Accelerated Degradation ◽  
Degradation Rates ◽  
Electrolysis Cells ◽  
Cell Test ◽  
Electrolysis Mode

An experimental study has been conducted to assess the performance of electrode-supported solid-oxide cells operating in the steam electrolysis mode for hydrogen production. Results presented in this paper were obtained from single cells, with an active area of 16 cm2 per cell. The electrolysis cells are electrode-supported, with yttria-stabilized zirconia (YSZ) electrolytes (∼10 μm thick), nickel-YSZ steam/hydrogen electrodes (∼1400 μm thick), and modified LSM or LSCF air-side electrodes (∼90 μm thick). The purpose of the present study is to document and compare the performance and degradation rates of these cells in the fuel cell mode and in the electrolysis mode under various operating conditions. Initial performance was documented through a series of voltage-current (VI) sweeps and AC impedance spectroscopy measurements. Degradation was determined through long-term testing, first in the fuel cell mode, then in the electrolysis mode. Results generally indicate accelerated degradation rates in the electrolysis mode compared to the fuel cell mode, possibly due to electrode delamination. The paper also includes details of an improved single-cell test apparatus developed specifically for these experiments.

Through-Plane Water Distribution in a Polymer Electrolyte Fuel Cell at Various Operating Temperatures

2010 ◽  
Author(s):  
Yun Wang ◽  
Ken S. Chen
Keyword(s):  
Fuel Cell ◽  
Polymer Electrolyte ◽  
Water Distribution ◽  
Electrochemical Reaction ◽  
Neutron Imaging ◽  
Polymer Electrolyte Fuel Cell ◽  
Two Phase ◽  
Model Predictions ◽  
Higher Temperature ◽  
Operating Temperatures

A multi-dimensional mathematical model is formulated for simulating the transport and electrochemical reaction phenomena in a polymer electrolyte fuel cell (PEFC). The model describes the two-phase flows, electrochemical reaction kinetics, species transport, and heat transfer, as well as their intrinsic couplings within a PEFC. Two-dimensional model predictions are computed for the two typical operating temperatures at 40 and 80 °C. Computed results reveal that liquid water level may be lower at the higher temperature operation due to water vapor phase diffusion. Detailed water and temperature distributions are displayed to explain the water and heat transport and their interaction. The computed water-content profiles are compared with available experimental data obtained by neutron imaging.

Visualization of Gas Bubble Behavior of a Regenerative Fuel Cell in Electrolysis Mode by Soft X-ray Radiography

2013 ◽  
Vol 58 (1) ◽  
pp. 353-360 ◽  
Author(s):  
O. F. Selamet ◽  
P. Deevanhxay ◽  
S. Tsushima ◽  
S. Hirai
Keyword(s):  
Fuel Cell ◽  
Gas Bubble ◽  
Bubble Behavior ◽  
X Ray ◽  
Regenerative Fuel Cell ◽  
Electrolysis Mode

scholarly journals Degradation of MCFC Materials in a 81 cm2 Single Cell Operated Under Alternated Fuel Cell/Electrolysis Mode

2021 ◽  
Vol 9 ◽  
Author(s):  
Stefano Frangini ◽  
Massimilano Della Pietra ◽  
Livia Della Seta ◽  
Claudia Paoletti ◽  
Juan Pedro Pérez-Trujillo
Keyword(s):  
Fuel Cell ◽  
Single Cell ◽  
Current Collector ◽  
Oxygen Electrode ◽  
Internal Resistance ◽  
Electrode Polarization ◽  
Post Mortem ◽  
Molten Carbonate ◽  
Operation Modes ◽  
Electrolysis Mode

The possibility of producing hydrogen from molten carbonate steam electrolysis using the well-established Molten Carbonate Fuel Cell (MCFC) technology was explored in this work. For this purpose, a 81 cm2 MCFC single cell assembled with conventional cell materials was operated under alternated fuel cell/electrolysis conditions at 650°C in a binary eutectic Li2CO3-K2CO3 electrolyte for about 400 h after an initial period of 650 h in which the cell worked only in the usual MCFC mode. A rapid cell performance loss in terms of cell internal resistance and electrode polarization was observed as soon as the cell started to work in the alternated fuel cell/electrolysis mode. After test completion, a post-mortem analysis was conducted to correlate the electrochemical response with cell materials degradation. Cell materials of the reverse cell were compared against a reference single cell that was assembled with the same materials and operated only in the fuel cell mode under comparable experimental conditions. Post-mortem analysis allowed to identify several serious stability issues of conventional MCFC materials when used in alternated operation modes. Thus, although the electrolyte matrix appeared almost unaffected, a significant amount of dissolved nickel was found in the matrix indicating that electrolysis operations promote an increasing chemical instability of the NiO oxygen electrode. A serious reduction of electrode porosity was also observed in both NiO oxygen and Ni metal fuel electrodes, which could explain the higher polarization resistance of the reversible cell in comparison to the reference MCFC cell. Furthermore, the oxygen current collector made with conventional 316L stainless steel was found to be seriously corroded under the alternated operation modes. Thus, the observed rapid increase in internal resistance in the reverse cell could be caused, at least in part, by an increased contact resistance between the oxygen electrode and the corroding current collector structure. Possible solutions for improving stability of electrodes and of the oxygen current collector in reverse MCFC cells were proposed and discussed in the final part of the work.

A numerical and experimental comparison of a single reversible molten carbonate cell operating in fuel cell mode and electrolysis mode

2018 ◽  
Vol 226 ◽  
pp. 1037-1055 ◽  
Author(s):  
Juan Pedro Perez-Trujillo ◽  
Francisco Elizalde-Blancas ◽  
Massimiliano Della Pietra ◽  
Stephen J. McPhail
Keyword(s):  
Fuel Cell ◽  
Experimental Comparison ◽  
Molten Carbonate ◽  
Electrolysis Mode

Validation and Calibration of a Proton Exchange Membrane Fuel Cell Model Against Dynamic Partial Pressure Data

2010 ◽  
Author(s):  
Arnab Roy ◽  
Ugur Pasaogullari ◽  
Michael W. Renfro ◽  
Baki M. Cetegen
Keyword(s):  
Experimental Data ◽  
Fuel Cell ◽  
Partial Pressure ◽  
Water Transport ◽  
Proton Exchange Membrane ◽  
Cell Model ◽  
Proton Exchange ◽  
Pressure Profiles ◽  
Model Predictions ◽  
Exchange Membrane

Transient experimental validation and investigation of the effect of diffusivity of porous layers on the dynamic water vapor partial pressure profiles of a proton exchange membrane fuel cell (PEMFC) during load change is presented. A three dimensional, isothermal, transient, single-phase computational fluid dynamics based model is developed to validate with the water partial pressure profiles experimentally measured during start-up conditions earlier in a 50 cm2 PEMFC having a single serpentine flow path in counter-flow configuration. The fluid flow within the serpentine channel geometry is simulated using a straight channel fuel cell model with total channel length equivalent to the stretched length of the entire serpentine path incorporating the same amount of pressure drop from inlet to outlet. The model equations are solved using a multi-domain approach incorporating water transport through membrane and multi-component species transport through porous diffusion layer. The transient model predictions of water partial pressure profiles of anode and cathode channels are found to be in good agreement within the error bounds of the experimental results. This validation is also indicative of the two different time scales i.e. initial anode dip due to electro-osmotic drag and recovery due to back diffusion from cathode to anode. Steady state model predictions are compared to check for accuracy simultaneously. The model also delineates the significance of effective diffusivity of porous Gas Diffusion Layers (GDL) and Catalyst Layers (CL) on transient characteristics. In order to come up with best parameters to validate with experimental data, a sensitivity analysis with parametric variations of effective porosity of GDL and CL is performed with a single experimental data set and then applied to the remaining sets. Results show that the CL diffusivity has a more pronounced effect on water accumulation as well as on temporal water transport than GDL diffusivity. The numerical simulation thus provides a validated set of quantitative model parameters along with an insight to the underlying physics of water transport phenomena in a PEMFC.

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