FES Funded ProjectsOutputs
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Measurement of Ionic Conductivity of PEM Water Electrolyzer ElectrodesIn this paper, the hydrogen pump technique is used to study the proton-transport resistance of polymer electrolyte membrane water electrolyzer electrodes. Three catalyst coated membranes made by sandwiching two membranes together were prepared, with two of them including an intermediate pseudo catalyst layer (PCL) with 35 and 55% wt. ionomer loadings. The proton-transport resistance was calculated by subtracting the overall resistance of the cell without a PCL from that with a PCL. The effect of the ionomer loading on the PCL proton conductivity was studied. As expected, the proton conductivity increased with increasing ionomer loading. The results are in line with the expectation based on the literature data and show that the hydrogen pump technique can be used to obtain the proton-transport resistance of the electrodes.T06-P04 University of Alberta | Publication | 2020-02-16 | | A Numerical Study on the Impact of Cathode Catalyst Layer Loading on the Open Circuit Voltage in a Proton Exchange Membrane Fuel CellThe open circuit voltage (OCV) in a proton exchange membrane fuel cell (PEMFC) is typically recorded as being approximately 300 mV lower than the equilibrium voltage computed by the Nernst equation. While a number of causes have been proposed, the voltage drop is generally attributed to the oxidation of crossover hydrogen in the cathode. A single phase, through-the-channel model is presented that includes hydrogen transport across the membrane, an empirical model for the hydrogen oxidation reaction (HOR) fit to experimental data obtained at high potentials and a multi-step kinetic model to describe the oxygen reduction reaction (ORR). Model predictions were compared to experimentally obtained OCVs and the results show that the model is capable of capturing the experimentally observed changes in OCV with platinum loading, as well as fuel cell performance; and that, at low Pt loadings, small quantities of unreacted hydrogen leave the cathode because the HOR is kinetically limited by oxide blocking and anion adsorption. A parametric study is used to show that a minimum OCV is achieved at ultra-low loadings. Results also show that only a multi-step ORR model can simultaneously capture polarization data and the OCV T06-P04 University of Alberta | Publication | 2021-04-19 | Michael Moore, "Shantanu Shukla ", "Stephan Voss ", "Kunal Karan ", Adam Zev Weber, "Iryna Zenyuk ", Secanell, M. | Measurement of the Protonic and Electronic Conductivities of PEM Water Electrolyzer ElectrodesReducing anode catalyst layer proton- and electron-transport resistances in polymer electrolyte membrane water electrolyzers is critical to improving its performance and maximizing catalyst utilization at high current density. A hydrogen pump technique is adapted to measure the protonic conductivity of IrOx-based catalyst layers. The protonic resistance of the catalyst layer is obtained by subtracting the protonic resistance of an assembly of two NRE211 membranes hot-pressed together from an assembly of two NRE211 membranes with an IrOx intermediate layer. The through-plane and in-plane electronic conductivities were also measured using two- and four-probe methods, respectively. Using these techniques, the protonic and electronic conductivities of the IrOx catalyst layers with varying Nafion loading were measured. The results show that the limiting charge-transport phenomena in the IrOx catalyst layer can be either proton or electron transport, depending on the ionomer loading in the catalyst layer. These results are validated by numerical simulation, as well as by comparison to the high-frequency resistance of an electrolyzer with the same layer.T06-P04 University of Alberta | Publication | 2020-10-20 | | Transient, multi-scale, multi-phase analysis of polymer electrolyte fuel cells and electrolyzersIn this presentation, the micro-scale simulation tools developed in the open-source software OpenFCST to estimate pore size distribution and transport properties from tomographic and stochastic reconstruction images will be discussed. A cluster-based full morphology algorithm will be presented to study water intrusion. Finite element solvers will also be presented to study transport and electrochemical reactions in CLs with varying pore-size distribution [4, 5]. Our results show that the pore-size distribution can clearly affect transport parameters and the liquid pressure at which the onset of mass transport is manifested. Then, a transient, macro-scale (volume-averaged), multi-phase membrane electrode assembly model, based on the pore-size distribution framework by Zhou et al. [3], will be presented that can integrate micro-scale findings into the macro-scale model. This advanced model will be shown to be able to predict fast and slow linear sweep voltammograms of fuel cell operation at low and high current density, impedance spectroscopy of fuel cells at low and moderate current density, and to predict large fluctuations in cell voltage/current density at high saturation. Numerical results will be compared to experimental data obtained using a single channel fuel cell. A similar framework will be proposed for electrolysis applications.T06-P04 University of Alberta | Activity | 2022-03-15 | | Reducing PEM Water Electrolysis Anode Catalyst Layer Loading: Impact of Layer Conductivity and ActivityRenewable energy can be used in a proton exchange membrane water electrolyzer to create green
hydrogen, thereby enabling large scale energy storage. One of the main disadvantages of this
technology is the use of rare and expensive precious metals such as iridium and platinum as the catalyst in the anode catalyst layer (ACL), making the reduction of the use of these materials a key priority to enabling further commercialization of this technology. This project uses numerical modelling, with experimental validation, to investigate the charge and kinetic characteristics of the ACL that allow for catalyst reduction to occur without inducing a significant reduction in performance. The study shows that ACLs with high electronic and protonic conductivity, and with a low kinetic activity, are sensitive to loading changes. Such ACLs were found to be representative of those composed of an Ir black catalyst, and such a loading dependence was demonstrated in-house. Highly active ACLs, with at least one phase exhibiting a very poor conductivity, were found to have a very poor catalyst utilization, allowing for catalyst reduction. IrOx based ACLs were found to exhibit such characteristics, however while there is experimental evidence in the literature for the predicted insensitivity to loading [Taie et al. ACS AMI 2020, Fujimura et al. ECS PRIME 2020], it was not reproduced in-house. It is hypothesized that the electronic conductivity of the ACL may be compression dependent leading to better utilization, or that the ACL fabrication method did not produce a uniform layer. T06-P04 University of Alberta | Activity | 2022-08-25 | Eric Beaulieu, Michael Moore, Manas Mandal, Himanshi Dhawan, Secanell, M. | Numerical Study of the Impact of Two-Phase Flow in the Anode Catalyst Layer on the Performance of Proton Exchange Membrane Water ElectrolysersT06-P04 University of Alberta | Publication | 2023-04-14 | | Characterising PEMWE performance: a numerical study on the impact of ACL permeability and electronic conductivityT06-P04 University of Alberta | Activity | 2022-07-23 | | A Numerical Study on the Impact of Low Electronic Conductivity on PEMWE Electrolyser PerformanceT06-P04 University of Alberta | Activity | 2021-05-30 | | Good Practices and Limitations of the Hydrogen Pump Technique for Catalyst Layer Protonic Conductivity EstimationT06-P04 University of Alberta | Publication | 2023-01-01 | | Numerical Modelling of Proton Exchange Membrane Water ElectrolysisT06-P04 | Publication | 2023-12-15 | Michael Moore | Development of Proton Conducting Fuel Cells using Nickel Metal SupportThe use of nickel, an excellent electronic conductor and YSZ, an good ionic conductor to the cell support greatly increases the current collection capability and mechanical properties of proton conducting fuel cells. These results will have important implications in using such cells in electrolysis mode to generate hydrogen or especially in reversible mode for load levelling of renewable wind or solar energy.T06-P04 | Publication | 2019-06-25 | Sajad Vafaeenezhad, Navjot Kaur Sandhu, Amir Reza Hanifi, Thomas H Etsell, "Partha Sarka" | Ni-YSZ a New Support for Proton Conducting Fuel CellsThe addition of only a small amount of YSZ (10 wt%) to the Ni support reduces polarization resistance and prevents severe Ni grain growth thereby providing a higher density of electrochemically active sites at the support /anode functional layer interface and more uniform distribution of fuel gas to the active sites. Perhaps most importantly it improves the mechanical properties of notoriously fragile proton conducting cells, a particularly critical consideration when developing reversible fuel cell/electrolysis cells that are particularly prone to cracking.T06-P04 | Publication | 2019-06-08 | Sajad Vafaeenezhad, Navjot Kaur Sandhu, Amir Reza Hanifi, Thomas H Etsell, "Partha Sarkar" | Microstructure and Long Term Stability of Ni-YSZ Anode Supported Fuel Cells: A ReviewA comprehensive review article focused on the importance that stability measurements be included in research papers as they are ultimately much more important than the initial electrolytic or fuel cell behaviour. Degradation issues is the main technical reason limiting widespread commercialization of SOEC/SOFCs.T06-P04 University of Alberta | Publication | 2021-05-12 | Sajad Vafaeenezhad, Hanifi, A., Miguel A Laguna-Bercero, Thomas Etsell, "Partha Sarkar " | Tailoring the solid oxide fuel cell anode support composition and microstructure for low-temperature applicationsT06-P04 University of Alberta | Publication | 2023-03-01 | Sajad Vafaeenezhad, Amir Reza Hanifi, Mark Cuglietta, Sadrzadeh, M., Partha Sarkar, Thomas H Etsell | Stability of infiltrated cathodes using Pr2NiO4$\mathplus$delta precursor for low-temperature fuel cell applicationsT06-P04 | Publication | 2022-09-01 | Sajad Vafaeenezhad, Miguel A Morales-Zapata, Amir Reza Hanifi, Miguel A Laguna-Bercero, "Ángel Larrea", Partha Sarkar, Thomas H Etsell | Microstructure and long-term stability of Ni\textendash YSZ anode supported fuel cells: a reviewT06-P04 | Publication | 2022-11-01 | Sajad Vafaeenezhad, Amir Reza Hanifi, Miguel A Laguna-Bercero, Thomas H Etsell, Partha Sarkar | Performance and Stability of Infiltrated Praseodymium Nickelate Cathodes for Low-Temperature Fuel Cell ApplicationsT06-P04 | Publication | 2022-01-01 | Sajad Vafaeenezhad, Miguel A Morales-Zapata, Amir Reza Hanifi, Miguel A Laguna-Bercero, Á ngel Larrea, Partha Sarkar, Thomas H Etsell | Studying the Microstructure of Electrodes for Low-temperature Solid Oxide Fuel Cell and Electrolysis ApplicationsT06-P04 | Publication | 2022-01-01 | Sajad Vafaeenezhad | High Performance Tubular Solid Oxide Fuel Cell based on Ba0.5Sr0.5Ce0.6Zr0.2Gd0.1Y0.1O3-d Proton Conductor ElectrolyteProton conducting electrolytes vs. oxygen ion conducting electrolytes have a major advantage in high temperature fuel cell/electrolysis cells - the fuel is not diluted as the cell is operated since water or CO2 is present at the air side rather than the fuel side. This novel composition was used to fabricate a tubular cell by a combination of slip casting and dip coating. Contrary to virtually all proton conductors, it appears chemically inert to both H2O vapour and CO2 as well as the other cell components. Correspondingly, it gave outstanding electrochemical performance producing a power output of 1 W/cm2 at 850C. This is among the highest output ever reported for a tubular cell with either a proton or oxygen ion conducting electrolyte. Electrochemical impedance spectroscopy was used in an effort to separate the various polarization losses.T06-P04, T02-C01 University of Alberta | Publication | 2018-04-24 | Taghi Amiri, "Kalpana Singh ", Hanifi, A., Thomas Etsell, Luo, J., "Venkataraman Thangadurai ", "Partha Sarkar " | Tetragonal Zirconia as Next Generation Support for Dry Reforming Solid Oxide Fuel CellThe usual structural support for ceramic fuel cells is nickel plus fully stabilized cubic zirconia containing 8 mol % Y2O3. This is the electrolyte composition as well. It has very good mechanical properties (at least relative to most ceramics). However, partially stabilized two-phase zirconia (tetragonal + cubic) containing 3 mol % Y2O3 has excellent mechanical properties due to monoclinic-to-tetragonal transformation toughening. Also, when mixed with nickel (the support also serves as one of the electrodes), it appears to slow down nickel agglomeration with an attendant loss of electronic conductivity. However, it has lower ionic conductivity that impacts the amount of triple phase interface (gas, electrode, electrolyte) available for electrochemical reaction. Preliminary results under syngas with the new support composition resulted in comparable, if not better, power outputT06-P04 University of Alberta | Activity | 2017-10-24 | | Direct Microwave Sintering of Poorly Coupled Ceramics in Electrochemical DevicesT06-P04 | Publication | 2022-08-01 | Taghi Amiri, Thomas H Etsell, Partha Sarkar | Using Microwave Irradiation for In-situ Infiltration of Electrodes in Solid Oxide Fuel CellsT06-P04 | Publication | 2022-02-01 | Taghi Amiri, Thomas H Etsell, Partha Sarkar | Improvements in Fabrication and Materials for Solid Oxide Fuel CellsT06-P04 | Publication | 2022-01-01 | Taghi Amiri | The Effect of Pore-Former Morphology on the Electrochemical Performance of Solid Oxide Fuel Cells under Combined Fuel Cell and Electrolysis ModesThis paper discusses a critical aspect of fabricating high temperature fuel cell/electrolysis cells - the amount and morphology of the pore former added to the electrodes prior to sintering that is used to create porosity to minimize both activation and concentration polarization. Fine spherical polymethyl methacrylate (PMMA) proved superior to angular somewhat coarser graphite. The fine pore structure decreased activation polarization by increasing the triple phase boundary length but still provided sufficient porosity for unrestricted gas flow. Most importantly, reversibility experiments (alternating between fuel cell and electrolysis modes) showed no degradation in performance for over 400 h.T06-P04 University of Alberta | Publication | 2018-04-24 | "Miguel A. Laguna-Bercero, A Laguna-Bercero, Miguel, Hanifi, A., "Lucile Manard ", Navjot K Sandhu, Neil E Anderson, Thomas Etsell, "Partha Sarkar " | Development of a Novel Proton Conducting Fuel Cell based on a Ni-YSZ SupportOne of the chief disadvantages of proton conducting fuel cells (and electrolytic cells) is a typical problem when ceramic materials are involved - poor mechanical properties. Robust oxygen ion conducting tubular cells have been fabricated with the Ni-yttria stabilized zirconia (YSZ) composite as the cell support (serves also as one of the electrodes). Not only does YSZ provide reasonable ionic conductivity and excellent chemical inertness but it is one of the best ceramic materials with respect to fracture toughness. This success has been capitalized on by using Ni-YSZ as the support for a tubular proton conducting cell. Reasonable power outputs from 600-700C were obtained. This could greatly increase the longevity and decrease fabrication costs of proton conducting cells. T06-P04 University of Alberta | Publication | 2018-04-24 | Hanifi, A., Navjot K Sandhu, Thomas Etsell, "Partha Sarkar " |
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