Journal articles: 'Fuel cell diagnostics'

1

Forrai, A., H. Funato, Y. Yanagita, and Y. Kato. "Fuel-Cell Parameter Estimation and Diagnostics." IEEE Transactions on Energy Conversion 20, no. 3 (September 2005): 668–75. http://dx.doi.org/10.1109/tec.2005.845516.

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Giczi, Wolfram, Christoph Kügele, Katharina Renner, and Jürgen Rechberger. "Fuel Cell Diagnostics with Smart Voltage Measurement." ATZ worldwide 116, no. 11 (October 2014): 12–17. http://dx.doi.org/10.1007/s38311-014-0236-6.

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Obeisun, O. A., Q. P. G. Meyer, J. Robinson, C. Gibbs, A. R. J. Kucernak, P. R. Shearing, and D. J. L. Brett. "Advanced Diagnostics Applied to a Self-Breathing Fuel Cell." ECS Transactions 61, no. 27 (October 1, 2014): 249–58. http://dx.doi.org/10.1149/06127.0249ecst.

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Milačić, Miloš, and Kevin Davies. "Polarization Based Statistical Approach to Fuel Cell Vehicle Diagnostics." ECS Transactions 5, no. 1 (December 19, 2019): 781–89. http://dx.doi.org/10.1149/1.2729059.

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Piela, Piotr, Robert Fields, and Piotr Zelenay. "Electrochemical Impedance Spectroscopy for Direct Methanol Fuel Cell Diagnostics." Journal of The Electrochemical Society 153, no. 10 (2006): A1902. http://dx.doi.org/10.1149/1.2266623.

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Merida, Walter. "An Empirical Model for Proton Exchange Membrane Fuel Cell Diagnostics." ECS Transactions 5, no. 1 (December 19, 2019): 229–39. http://dx.doi.org/10.1149/1.2729005.

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7

Hirschfeld, J. A., H. Lustfeld, M. Reißel, and B. Steffen. "Tomographic diagnostics of current distributions in a fuel cell stack." International Journal of Energy Research 34, no. 3 (November 9, 2009): 284–92. http://dx.doi.org/10.1002/er.1634.

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Tsalapati, E., C. W. D. Johnson, T. W. Jackson, L. Jackson, D. Low, B. Davies, L. Mao, and A. West. "Enhancing polymer electrolyte membrane fuel cell system diagnostics through semantic modelling." Expert Systems with Applications 163 (January 2021): 113550. http://dx.doi.org/10.1016/j.eswa.2020.113550.

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9

Lin, Rong-Heng, Zi-Xiang Pei, Ze-Zhou Ye, Cheng-Cheng Guo, and Bu-Dan Wu. "Hydrogen fuel cell diagnostics using random forest and enhanced feature selection." International Journal of Hydrogen Energy 45, no. 17 (March 2020): 10523–35. http://dx.doi.org/10.1016/j.ijhydene.2019.10.127.

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Martemianov, S., A. Thomas, A. Gervex, P. Lagonotte, and J. P. Poirot-Crouvezier. "Electrochemical noise diagnostics of PEM fuel cell stack for micro-cogeneration application." Journal of Solid State Electrochemistry 25, no. 12 (October 21, 2021): 2835–47. http://dx.doi.org/10.1007/s10008-021-05053-2.

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Zhu, Y., W. H. Zhu, and B. J. Tatarchuk. "Dynamic Analysis and Diagnostics of a High Temperature PEM Fuel Cell Stack." ECS Transactions 50, no. 2 (March 15, 2013): 745–51. http://dx.doi.org/10.1149/05002.0745ecst.

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12

Easton, E. Bradley. "Development of Materials and Electrochemical Diagnostics for Fuel Cell-Based Ethanol Sensors." ECS Meeting Abstracts MA2020-01, no. 34 (May 1, 2020): 2415. http://dx.doi.org/10.1149/ma2020-01342415mtgabs.

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Medici, Ezequiel F., and Jeffrey S. Allen. "Modeling and Diagnostics of Fuel Cell Porous Media for Improving Water Transport." ECS Transactions 41, no. 1 (December 16, 2019): 165–78. http://dx.doi.org/10.1149/1.3635552.

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Ibrahim, Mona, Ursula Antoni, Nadia Yousfi Steiner, Samir Jemei, Celestin Kokonendji, Bastian Ludwig, Philippe Moçotéguy, and Daniel Hissel. "Signal-Based Diagnostics by Wavelet Transform for Proton Exchange Membrane Fuel Cell." Energy Procedia 74 (August 2015): 1508–16. http://dx.doi.org/10.1016/j.egypro.2015.07.708.

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15

Le, G. T., L. Mastropasqua, J. Brouwer, and S. B. Adler. "Simulation-Informed Machine Learning Diagnostics of Solid Oxide Fuel Cell Stack with Electrochemical Impedance Spectroscopy." Journal of The Electrochemical Society 169, no. 3 (March 1, 2022): 034530. http://dx.doi.org/10.1149/1945-7111/ac59f4.

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This paper reports our initial development of simulation-informed machine learning algorithms for failure diagnostics in solid oxide fuel cell (SOFC) systems. We used physics-based models to simulate electrochemical impedance spectroscopy (EIS) response of a short SOFC stack under normal conditions and under three different failure modes: fuel maldistribution, delamination, and oxidant gas crossover to the anode channel. These data were used to train a support vector machine (SVM) model, which is able to detect and differentiate these failures in simulated data under various conditions. The SVM model can also distinguish these failures from simulated uniform degradation that often occurs with long-term operation. These encouraging results are guiding our ongoing efforts to apply EIS as a failure diagnostic for real SOFC cells and short stacks.

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Cooley, John J., Peter Lindahl, Clarissa L. Zimmerman, Matthew Cornachione, Grant Jordan, Steven R. Shaw, and Steven B. Leeb. "Multiconverter System Design for Fuel Cell Buffering and Diagnostics Under UAV Load Profiles." IEEE Transactions on Power Electronics 29, no. 6 (June 2014): 3232–44. http://dx.doi.org/10.1109/tpel.2013.2274600.

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Halvorsen, Ivar J., Ivan Pivac, Dario Bezmalinović, Frano Barbir, and Federico Zenith. "Electrochemical low-frequency impedance spectroscopy algorithm for diagnostics of PEM fuel cell degradation." International Journal of Hydrogen Energy 45, no. 2 (January 2020): 1325–34. http://dx.doi.org/10.1016/j.ijhydene.2019.04.004.

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18

Basu, Saptarshi, Hang Xu, Michael W. Renfro, and Baki M. Cetegen. "In Situ Optical Diagnostics for Measurements of Water Vapor Partial Pressure in a PEM Fuel Cell." Journal of Fuel Cell Science and Technology 3, no. 1 (July 21, 2005): 1–7. http://dx.doi.org/10.1115/1.2133799.

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A fiber optic coupled diode laser sensor has been constructed for in situ measurements of water vapor partial pressure in active proton-exchange membrane (PEM) fuel cell systems. The bipolar plate of a prototypical PEM fuel cell was modified to allow for transmission of a near infrared laser beam through the flow channels on either the fuel or oxidizer side of its membrane-electrode assembly. The laser wavelength was scanned over several water rotational and vibrational transitions and the light absorption was detected by measuring the transmitted laser power through the device. The intensity and line shape of the measured transition was used to extract path-averaged values for the water vapor partial pressure. Measurements were initially taken in a non-operating cell with known temperature and humidity input gas streams to calibrate and test the optical device. A technique for rapid determination of the water partial pressure was developed. The optical technique is applicable over a significant temperature and humidity operating range of a PEM fuel cell. The measurement technique was applied to an operating PEM fuel cell system to examine the effects of incoming gas humidity and load on the water vapor partial pressure variation in one of the flow channels.

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19

Caponetto, Riccardo, Fabio Matera, Emanuele Murgano, Emanuela Privitera, and Maria Gabriella Xibilia. "Fuel Cell Fractional-Order Model via Electrochemical Impedance Spectroscopy." Fractal and Fractional 5, no. 1 (March 6, 2021): 21. http://dx.doi.org/10.3390/fractalfract5010021.

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The knowledge of the electrochemical processes inside a Fuel Cell (FC) is useful for improving FC diagnostics, and Electrochemical Impedance Spectroscopy (EIS) is one of the most used techniques for electrochemical characterization. This paper aims to propose the identification of a Fractional-Order Transfer Function (FOTF) able to represent the FC behavior in a set of working points. The model was identified by using a data-driven approach. Experimental data were obtained testing a Proton Exchange Membrane Fuel Cell (PEMFC) to measure the cell impedance. A genetic algorithm was firstly used to determine the sets of fractional-order impedance model parameters that best fit the input data in each analyzed working point. Then, a method was proposed to select a single set of parameters, which can represent the system behavior in all the considered working conditions. The comparison with an equivalent circuit model taken from the literature is reported, showing the advantages of the proposed approach.

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20

Ritzberger, Daniel, Christoph Hametner, and Stefan Jakubek. "A Real-Time Dynamic Fuel Cell System Simulation for Model-Based Diagnostics and Control: Validation on Real Driving Data." Energies 13, no. 12 (June 17, 2020): 3148. http://dx.doi.org/10.3390/en13123148.

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Fuel cell systems are regarded as a promising candidate in replacing the internal combustion engine as a renewable and emission free alternative in automotive applications. However, the operation of a fuel cell stack fulfilling transient power-demands poses significant challenges. Efficiency is to be maximized while adhering to critical constraints, avoiding adverse operational conditions (fuel starvation, membrane flooding or drying, etc.) and mitigating degradation as to increase the life-time of the stack. Owing to this complexity, advanced model-based diagnostic and control methods are increasingly investigated. In this work, a real time stack model is presented and its experimental parameterization is discussed. Furthermore, the stack model is integrated in a system simulation, where the compressor dynamics, the feedback controls for the hydrogen injection and back-pressure valve actuation, and the purging strategy are considered. The resulting system simulation, driven by the set-point values of the operating strategy is evaluated and validated on experimental data obtained from a fuel cell vehicle during on-road operation. It will be shown how the internal states of the fuel cell simulation evolve during the transient operation of the fuel cell vehicle. The measurement data, for which this analysis is conducted, stem from a fuel cell research and demonstrator vehicle, developed by a consortium of several academic and industrial partners under the lead of AVL List GmbH.

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21

Sun, Ying, Thomas Kadyk, Andrei Kulikovsky, and Michael Eikerling. "(Digital Presentation) Concentration Admittance Spectroscopy for Oxygen Transport Diagnostics in Polymer Electrolyte Fuel Cells." ECS Meeting Abstracts MA2022-02, no. 39 (October 9, 2022): 1401. http://dx.doi.org/10.1149/ma2022-02391401mtgabs.

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Polymer electrolyte fuel cells will be crucial as efficient and environmentally benign energy conversion devices in a sustainable hydrogen economy. The further development and deployment of PEFCs require powerful diagnostic tools to assess the interplay of transport and reaction processes in an operating cell, extract the relevant parameters, and perform causal analyses of deviations from healthy cell operation. The diagnostic capabilities of electrochemical impedance spectroscopy (EIS) are widely known and extensively exploited in disentangling the transport and reaction processes in electrochemical cells. The kinetics of the oxygen reduction reaction (ORR) and thus the current density produced by a PEFC at a given cell voltage are not only sensitive to modulations in the electrode potential (or cell voltage), as used in EIS, but they are also affected by modulations in oxygen concentration. The latter effect gives rise to another impedance-type response referred to as concentration or pressure impedance. An oxygen concentration impedance (ζ = δE/δc, where δE and δc are the small-amplitude harmonic perturbations of cell voltage and oxygen concentration) could provide useful complementary capabilities to scrutinize oxygen transport processes. Various experimental works have explored the possibility of probing the response of the PEFC cell voltage with small-amplitude periodic perturbations in oxygen concentration or gas pressure1-6 and numerical models have been developed to rationalize these response functions.4,7-9 The presented work builds on a recently developed analytical model for the oxygen concentration/pressure impedance.10,11 In that work, the limit of large air flow stoichiometry and large oxygen transport loss in the catalyst layer was considered. The present work relaxes these assumptions and it focuses on the case of the so-called concentration admittance spectroscopy, which is based on the hitherto unexplored idea of measuring the response in the oxygen concentration variation to a voltage perturbation. We will present a newly developed quasi-2D model for the cathode side concentration admittance of a PEFC that accounts for oxygen transport in the flow-field channel, in the gas diffusion layer, and in the cathode catalyst layer. An analytical expression for the concentration admittance will be presented and parametric dependencies of the static admittance will be discussed. We will demonstrate how information on the oxygen transport coefficients in the flow field channel, gas diffusion layer, and catalyst layer can be drawn from the admittance at the air channel outlet. References: 1Amir M Niroumand, Walter Merida, Michael Eikerling, and Mehrdad Saif, Electrochemistry Communications, 12(1):122, 2010. 2Erik Engebretsen, Thomas J Mason, Paul R Shearing, Gareth Hinds, and Dan JL Brett, Electrochemistry Communications, 75:60 63, 2017. 3Anantrao Vijay Shirsath, Stephane Rael, Caroline Bonnet, and Francois Lapicque , Electrochimica Acta, 363:137157, 2020. 4Lutz Schiffer, Anantrao Vijay Shirsath, Stephane Rael, Caroline Bonnet, Francois Lapicque, and Wolfgang G Bessler. Journal of The Electrochemical Society, 169(3):034503, 2022. 5Qingxin Zhang, Michael H Eikerling, and Byron D Gates. In ECS Meeting Abstracts, number 20, page 1586, 2020. 6Qingxin Zhang, Hooman Homayouni, Byron Gates, Michael Eikerling, and Amir Niroumand. Journal of The Electrochemical Society, 2022. 7Antonio Sorrentino, Tanja Vidakovic-Koch, Richard Hanke-Rauschenbach, and Kai Sundmacher. Electrochim. Acta, 243:53 64, 2017. 8Antonio Sorrentino, T Vidakovic-Koch, and Kai Sundmacher. J. Power Sources, 412:331 335, 2019. 9Antonio Sorrentino, Kai Sundmacher, and Tanja Vidakovic-Koch. D. Electrochim. Acta, 390:138788, 2021. 10Andrei Kulikovsky. eTransportation 2:100026, 2019. 11Andrei Kulikovsky. J. Electroanal. Chem., 899:115672, 2021. Figure 1

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22

Adekunle, Ademola, Vijaya Raghavan, and Boris Tartakovsky. "Real-Time Performance Optimization and Diagnostics during Long-Term Operation of a Solid Anolyte Microbial Fuel Cell Biobattery." Batteries 5, no. 1 (January 15, 2019): 9. http://dx.doi.org/10.3390/batteries5010009.

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This study describes a novel approach for real-time energy harvesting and performance diagnostics of a solid anolyte microbial fuel cell (SA-MFC) representing a prototype smart biobattery. The biobattery power output was maximized in real time by combining intermittent power generation with a Perturbation-and-Observation algorithm for maximum power point tracking. The proposed approach was validated by operating the biobattery under a broad range of environmental conditions affecting power production, such as temperature (4–25 °C), NaCl concentration (up to 2 g L−1), and carbon source concentration. Real-time biobattery performance diagnostics was achieved by estimating key internal parameters (resistance, capacitance, open circuit voltage) using an equivalent electrical circuit model. The real time optimization approach ensured maximum power production during 388 days of biobattery operation under varying environmental conditions, thus confirming the feasibility of biobattery application for powering small electronic devices in field applications.

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23

Le, Giang Tra, Luca Mastropasqua, Stuart B. Adler, and Jack Brouwer. "Operando Diagnostics of Solid Oxide Fuel Cell Stack Via Electrochemical Impedance Spectroscopy Simulation-Informed Machine Learning." ECS Meeting Abstracts MA2021-03, no. 1 (July 23, 2021): 38. http://dx.doi.org/10.1149/ma2021-03138mtgabs.

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Le, Giang Tra, Luca Mastropasqua, Stuart B. Adler, and Jack Brouwer. "Operando Diagnostics of Solid Oxide Fuel Cell Stack Via Electrochemical Impedance Spectroscopy Simulation-Informed Machine Learning." ECS Transactions 103, no. 1 (July 9, 2021): 1201–11. http://dx.doi.org/10.1149/10301.1201ecst.

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25

Hirschfeld, J. A., H. Lustfeld, M. Reißel, and B. Steffen. "A novel scheme for precise diagnostics and effective stabilization of currents in a fuel cell stack." International Journal of Energy Research 34, no. 3 (December 21, 2009): 293–302. http://dx.doi.org/10.1002/er.1662.

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26

Senin, Petr V., Dmitriy A. Galin, and Leonid O. Krush. "Using Diagnostics to Research the Operational Reliability of Electronic Engine Control Systems of Skoda Car." Engineering Technologies and Systems 32, no. 2 (June 30, 2022): 235–48. http://dx.doi.org/10.15507/2658-4123.032.202202.235-248.

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Introduction. Some physical processes active in the electronic engine control systems lead to wear and tear of the system elements. Experience in operating and diagnosing vehicles at the service station has shown that there is the operation of vehicles with failures, many of which subsequently lead to malfunctions of different complexities. The purpose of the study is to apply diagnostics for determining the operational reliability and assessing the technical condition of electronic engine control systems. Materials and Methods. A batch of cars was selected to assess the operational reliability of modern electronic engine control system. There were carried out experimental tests of Skoda Octavia cars with 1.8 TSI CDAB 152 hp Euro5 engine and CDAA 160 hp Euro5 engine. The sample consisted of 60 vehicles. Every vehicle was registered for diagnostics, pre-maintenance and computer diagnostics. After a short test, the vehicle was taken back to the service station and subjected to a detailed diagnosis of the electronic engine control system. Results. The results of analyzing reliability of the main elements of the electronic engine control system have been obtained. It can be concluded that most of the failures of the structural elements of the electronic engine control system occur within the actuators of the system, which have moving elements, sensors measuring the parameters of the system wear out to a lesser extent. The analysis of dependence of failure rates of the fuel pump pressure regulator on operating time intervals has been carried out. Discussion and Conclusion. It was determined that the spark plugs have the least mileage lifetime. At the same time, the failure within the fuel pressure regulator of the car fuel system occurs most frequently (19.8% of total). The resource of this element of the electronic engine control system averages 125,000 km. It is proved that diagnostics using modern technological equipment is effective.

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Benhaddouch, Tinsley Elizabeth, John Marcial, Christopher Metler, Shekhar Bhansali, and Dongmei Dong. "Real-Time Continuous Monitoring of Fuel Cell Ionomer Degradation with Electrochemical Inline Micro Sensor Arrays." ECS Meeting Abstracts MA2022-02, no. 61 (October 9, 2022): 2256. http://dx.doi.org/10.1149/ma2022-02612256mtgabs.

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Proton Exchange Membrane Fuel Cells (PEMFCs) are the preferred energy source for green transportation over CO2 emitting engines. In Nafion®-based PEMFCs, the radical attack causes polymer chain scission and irreversible reaction. It results in the global and local thinning of the ionomer, followed by producing fluorinated and sulfated degradation materials into reactant outlet streams. Synchronous fluorinated and sulfated degradation products will accumulate into reactant outlet streams. Radical attack diminishes the performance and stability of membrane electrode assembly (MEA). Chemical degradation will increase the flow rate of the relevant fluorinated degradation products. The concentrations are enhanced at elevated temperatures and lower humidity conditions. The byproduct fluoride and sulfate anion emission rates can be drawn as the signature of the PEMFC degradations. Electrochemical micro-sensors have been promising diagnostics tools due to low cost, small size, robustness, and their applications for continuous real-time monitoring. We have used fluoride emission as a sensing model. Highly fluoride-sensitive membranes (LaF3/CaF2) for inline microsensor arrays have been introduced as the sensing active layer. The functionalization of the working electrode varies the selectivity/sensitivity. High sensitivity sub 1 ppm has been achieved after optimizing the sensing layer deposited by spin-coating. In addition, advanced deep learning (DL) and long-short term memory (LSTM) algorithms will be used for the sensor-based predictive maintenance (PM) of PEMFCs. Even higher sensitivities sub 100 ppt and prediction accuracy for the end of life (EOL) can be achieved based on LSTM algorithms. The development of inline microsensor arrays gives a complementary approach to existing PEMFC characterization and diagnostics techniques. Figure 1

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28

Mayur, Manik, Mathias Gerard, Pascal Schott, and Wolfgang Bessler. "Lifetime Prediction of a Polymer Electrolyte Membrane Fuel Cell under Automotive Load Cycling Using a Physically-Based Catalyst Degradation Model." Energies 11, no. 8 (August 8, 2018): 2054. http://dx.doi.org/10.3390/en11082054.

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One of the bottlenecks hindering the usage of polymer electrolyte membrane fuel cell technology in automotive applications is the highly load-sensitive degradation of the cell components. The cell failure cases reported in the literature show localized cell component degradation, mainly caused by flow-field dependent non-uniform distribution of reactants. The existing methodologies for diagnostics of localized cell failure are either invasive or require sophisticated and expensive apparatus. In this study, with the help of a multiscale simulation framework, a single polymer electrolyte membrane fuel cell (PEMFC) model is exposed to a standardized drive cycle provided by a system model of a fuel cell car. A 2D multiphysics model of the PEMFC is used to investigate catalyst degradation due to spatio-temporal variations in the fuel cell state variables under the highly transient load cycles. A three-step (extraction, oxidation, and dissolution) model of platinum loss in the cathode catalyst layer is used to investigate the cell performance degradation due to the consequent reduction in the electro-chemical active surface area (ECSA). By using a time-upscaling methodology, we present a comparative prediction of cell end-of-life (EOL) under different driving behavior of New European Driving Cycle (NEDC) and Worldwide Harmonized Light Vehicles Test Cycle (WLTC).

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Marra, Dario, Marco Sorrentino, Cesare Pianese, and Boris Iwanschitz. "A neural network estimator of Solid Oxide Fuel Cell performance for on-field diagnostics and prognostics applications." Journal of Power Sources 241 (November 2013): 320–29. http://dx.doi.org/10.1016/j.jpowsour.2013.04.114.

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He, Cheng, Ami C. Yang-Neyerlin, and Bryan S. Pivovar. "Probing Anion Exchange Membrane Fuel Cell Cathodes by Varying Electrocatalysts and Electrode Processing." Journal of The Electrochemical Society 169, no. 2 (February 1, 2022): 024507. http://dx.doi.org/10.1149/1945-7111/ac4daa.

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To date, several high-performing anion exchange membrane fuel cells (AEMFCs) have been demonstrated, but most these studies have focused on Pt containing cathodes with high loadings. Here, we explore and compare the performance and perform electrochemical diagnostics on three leading AEMFC cathode electrocatalysts: Pt/C, Ag/C, and Fe–N–C with electrodes that have been processed with either powder or dispersion-based ionomers using perfluorinated anion exchange polymers. Pt/C had the highest performance but also showed a strong dependence on ionomer type, with powder ionomer exhibiting much higher performance. These results were consistent with the observations for Ag/C but did not hold for the Fe–N–C catalyst where almost no change was observed between powder and dispersion-based ionomers. This is the first-time the impact of powder and dispersion ionomer with different classes of cathode electrocatalysts on the fuel cell performance have been compared, and the results have strong implications for the ability to achieve high performance at low loadings and for better understanding catalyst-ionomer interactions within AEMFCs.

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Perry, Mike L., and Robert M. Darling. "(Invited) Development of a Simple and Rapid Diagnostic for Redox-Flow-Battery Cells." ECS Meeting Abstracts MA2022-02, no. 46 (October 9, 2022): 1703. http://dx.doi.org/10.1149/ma2022-02461703mtgabs.

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Prof. Robert Savinell has made many important contributions to fuel-cell and flow-battery systems. Both of these systems utilize electrochemical flow cells to either generate or store electricity. Because of this commonality, one can leverage concepts used in one for adoption in the other. An important topic for any electrochemical system is durability. A considerable amount of work has been on this topic with polymer-electrolyte fuel cells (PEFCs); in fact, a textbook devoted to this topic was published over a decade ago [1]. However, despite a recent renaissance in redox-flow-battery (RFB) technologies, assessing the durability of RFB cells is a topic that has not received much attention in the open literature, to date, and further research is needed to better understand dominant degradation mechanisms [2, 3]. A simple and fast diagnostic tool has been developed for analyzing polymer-electrolyte fuel-cell degradation [4, 5]. The tool is based on analyzing changes in polarization curves of a cell over its lifetime. Using the polarization-change curve methodology, the primary mechanism for degradation (kinetic, ohmic, and/or transport related) can be identified. This technique can also be applied to RFB cells, which will be the focus of this presentation. This diagnostic tool provides a simple method for rapid determination of primary degradation mechanisms. Areas for more detailed future investigations shall also be summarized. References Modern Topics in Polymer Electrolyte Fuel Cell Degradation, Mench, M.; Kumbur, E.; and Veziroglu, T.; Editors; Elsevier, Denmark (2011). Yuan, X.-Z.; Song, C.; Platt, A.; Zhao, N.; Wang, H.; Li, H.; Fatih, K.; Jang, D.; “A review of all-vanadium redox flow battery durability: Degradation mechanisms and mitigation strategies,” J. Energy Res., 43 (2019) 6599−6638. Yao, Y.; Lei, J.; Shi, Y.; Ai, F.; Lu, Y. C.; “Assessment methods and performance metrics for redox flow batteries,” Energy, 6 (2021) 582−588. L. Perry, R. Balliet, and R. Darling, “Experimental Diagnostics and Durability Testing Protocols,” a chapter in [1]. M. Pant, Z. Yang, M. L. Perry, and A. Z. Weber, “Development of a Simple and Rapid Diagnostic Method for Polymer-Electrolyte Fuel Cells,” J. Electrochem. Soc., 165 (2018) F3007.

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Han, Soo-Bin, Hwanyeong Oh, Won-Yong Lee, Jinyeon Won, Suyong Chae, and Jongbok Baek. "On-Line EIS Measurement for High-Power Fuel Cell Systems Using Simulink Real-Time." Energies 14, no. 19 (September 26, 2021): 6133. http://dx.doi.org/10.3390/en14196133.

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Impedance measurements by EIS are used to build a physical circuit-based model that enables various fault diagnostics and lifetime predictions. These research areas are becoming increasingly crucial for the safety and preventive maintenance of fuel cell power systems. It is challenging to apply the impedance measurement up to commercial applications at the field level. Although EIS technology has been widely used to measure and analyze the characteristics of fuel cells, EIS is applicable mainly at the single-cell level. In the case of stacks constituting a power generation system in the field, it is difficult to apply EIS due to various limitations in the high-power condition with uncontrollable loads. In this paper, we present a technology that can measure EIS on-line by injecting the perturbation current to fuel cell systems operating in the field. The proposed EIS method is developed based on Simulink Real-Time so that it can be applied to embedded devices. Modeling and simulation of the proposed method are presented, and the procedures from the simulation in virtual space to the real-time application to physical systems are described in detail. Finally, actual usefulness is shown through experiments using two physical systems, an impedance hardware simulator and a fuel cell stack with practical considerations.

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Deevanhxay, Phengxay, Takashi Sasabe, Katsunori Minami, Shohji Tsushima, and Shuichiro Hirai. "Oblique Soft X-Ray Tomography as a Non-Destructive Method for Morphology Diagnostics in Degradation of Proton-Exchange Membrane Fuel Cell." Electrochimica Acta 135 (July 2014): 68–76. http://dx.doi.org/10.1016/j.electacta.2014.04.144.

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Giesbrecht, Patrick K., and Michael S. Freund. "Advanced Electrochemical Impedance Analysis Using Distribution of Relaxation Times for in Operando Mechanistic Insights of Fuel Cell and Water Electrolyzer Designs." ECS Meeting Abstracts MA2022-02, no. 50 (October 9, 2022): 2436. http://dx.doi.org/10.1149/ma2022-02502436mtgabs.

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The development of sustainable and carbon-neutral alternative energy frameworks and chemical feedstocks requires rapid production of scalable water electrolyzer designs for hydrogen production.[1] Coupling electrolyzers to renewable energy supplies can provide a ‘green’ hydrogen production pathway, enabling clean production of chemical feedstocks as well as an energy storage framework. Current acid-based electrolyzer designs, however, integrate precious metals for stable operation, where drastic reductions in iridium use and increased cell durability are required for scalable deployment.[2] This requires the ability to monitor changes to the cell in operando for rapid diagnostics during initial and long-term operation under sustained or intermittent profiles. One technique proposed is electrochemical impedance spectroscopy (EIS), which can provide a breakdown of the cell resistances based on the timescale of the process.[3] Further analysis by circuit modeling, however, requires significant insight into the system for accurate interpretations. By coupling conventional EIS methods with distribution of relaxation times (DRT) analysis, the number of processes impacting cell operation can be determined without a priori knowledge of the system.[4] This has improved circuit modeling analysis of Li-ion batteries and solid oxide fuel cells.[5] Here, we demonstrate the power of EIS-coupled DRT analysis by analyzing the operation porous cathode and anode films of Nafion-based electrolyzer cells in half-cell and full cell configuration. Analysis of the electrodes in half-cell configurations provides estimates of kinetic parameters, active area, ionic conductivity, and diffusion coefficients associated with the electrode from a single EIS spectrum that are comparable to values obtained from in situ values.[6] Further analysis of the full cell operation with variable cathode gas composition provides insight as to the effect of the cathode gas composition on both the cathode and anode operation and stability. The work presented here will show the versatility and limitations of DRT-coupled EIS analysis of novel fuel cell and electrolyzer designs as well as present key findings for improving electrolyzer performance and stability. [1]Ayers, K. et al. Annu. Rev. Chem. Biomolec. Eng. 2019, 10, 219-239. [2]Pham, C. et al Adv. Energy Mater. 2021, 11, 2101998. [3]Liu, H. et al. J. Phys. Chem. Lett. 2022, 13, 6520-6531. [4]Wan, T. et al. Electrochimica Acta 2015, 184, 483-499. [5]Dierickx, S., Ivers-Tiffee, E. Electrochimica Acta 2020, 355, 136764. [6]Giesbrecht, P.K., Freund, M.S. J. Phys. Chem. C 2022, 126, 132-150.

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LARIBI, Slimane, Khaled MAMMAR, Fatima Zohra ARAMA, and Touhami GHAITAOUI. "Analyze of Impedance for Water Management in Proton Exchange Membrane Fue Fells Using Neural Networks Methodology." Algerian Journal of Renewable Energy and Sustainable Development 01, no. 01 (June 15, 2019): 69–78. http://dx.doi.org/10.46657/ajresd.2019.1.1.7.

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The objective of this work is to define and to implement a simple method to assess the impacts of relative humidity and operating time on the fuel cell impedance. The method is based on the physical model of Randles with CPE and a mathematical tool for identifying various parameters based on the least squares’ method. The objective of the theoretical model development is the model implementation of the control system and water management of predictive diagnostics. Artificial neural networks are used to create the optimum impedance model. The model is applied for the identification of all resistors (internal resistors measured at high frequency, biasing resistors measured at high frequency) which are characterized by a high sensitivity for both cases, the flooding or drying of the cell heart (membrane and electrodes). This model is able to easily generate Nyquist diagram for any condition of relative humidity and operating time, it helped define the stack hydration status. Based on the obtained results, the model demonstrated a best flexible response, accurate and fast. The developed model can be integrated into a water management control system in PEM fuel cells.

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Alboghobeish, Mohammad, Andrea Monforti Ferrario, Davide Pumiglia, Massimiliano Della Pietra, Stephen J. McPhail, Sergii Pylypko, and Domenico Borello. "Developing an Automated Tool for Quantitative Analysis of the Deconvoluted Electrochemical Impedance Response of a Solid Oxide Fuel Cell." Energies 15, no. 10 (May 18, 2022): 3702. http://dx.doi.org/10.3390/en15103702.

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Despite being commercially available, solid oxide fuel cell (SOFC) technology requires further study to understand its physicochemical processes for diagnostics, prognostics, and quality assurance purposes. Electrochemical impedance spectroscopy (EIS), a widely used characterization technique for SOFCs, is often accompanied by the distribution of relaxation times (DRT) as a method for deconvoluting the contribution of each physicochemical process from the aggregated impedance response spectra. While EIS yields valuable information for the operation of SOFCs, the quantitative analysis of the DRT and its shifts remains cumbersome. To address this issue, and to create a replicable benchmark for the assessment of DRT results, a custom tool was developed in MATLAB to numerically analyze the DRT spectra, identify the DRT peaks, and assess their deviation in terms of peak frequency and DRT amplitude from nominal operating conditions. The preliminary validation of the tool was carried out by applying the tool to an extensive experimental campaign on 23 SOFC button-sized samples from three production batches in which EIS measurements were performed in parametric operating conditions. It was concluded that the results of the automated analysis via the developed tool were in accordance with the qualitative analysis of previous studies. It is capable of providing adequate additional quantitative results in terms of DRT shifts for further analysis and provides the basis for better interoperability of DRT analyses between laboratories.

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Saha, Prantik, Tim Van Cleve, and Kenneth C. Neyerlin. "In-situ Electrochemical Diagnostics for Morphological Study of CO₂ Reduction Electrodes." ECS Meeting Abstracts MA2022-02, no. 39 (October 9, 2022): 1438. http://dx.doi.org/10.1149/ma2022-02391438mtgabs.

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Electrochemical CO2 reduction (CO2R) devices have immense potential to capture the effluent CO2 in hard-to-decarbonize sectors and convert them to valuable chemicals like CO, C2H4, CH4, alcohols etc. Inside these devices, CO2R occurs inside gas diffusion electrodes (GDE). The reaction rate strongly depends on the local environment at the catalyst-electrolyte interface like ionomer binders, pH, electrolyte cations etc[1]. The transport of reactants and products to and from the catalyst-electrolyte interface depends on the pore-space structure of the GDE, which comprises mostly of micro and smaller mesopores. Ionomer binders used in these GDEs also affect the Faradaic efficiencies (FE) of the CO2R products. Moreover, experimental results indicate that the KOH fed as the anolyte in alkaline CO2 electrolyzers impact the performance of CO2R at the cathode [2]. At present, there is a lack of simple experimental methods in the literature to systematically study the local electrochemical environments present in real decices and identify critical limiting phenomena. We have developed a novel setup to study the morphological aspects of CO2 electrodes at the electrode level without the complexities due to water splitting at the anode. A stable reference electrode, an ion-exchange membrane, and the CO2R cathode are integrated together to form a membrane electrode assembly (MEA) for the purpose of precise and reproducible electrochemical experimentation. AC impedance spectroscopy (EIS) is used to measure capacitance and ion-transport resistance of the CO2R electrodes. A novel MEA setup, previously developed in this group to study oxygen mass transport resistance (MTR) in non-Platinum group metal fuel cells electrodes, is used to measure MTR of CO2 in the CO2R electrodes [3]. We vary the experimental conditions used in the CO2R experiments, like feed gas RH, KOH flow rate etc., and measure the above-mentioned properties. In addition, we also used these diagnostic methods to study the role of ionomer, specifically the ionomer-catalyst interaction in these electrodes. Experiments done by our group members indicate that a suitable electrode ink recipe (catalyst and ionomer loading, organic solvent etc.) is required to optimize the performance of CO2R inside these electrodes. Overall, these techniques can be used to understand the CO2R trends of various electrodes and to identify key design parameters for more efficient CO2 reduction electrodes. Important references: Bui et al., Engineering Catalyst–Electrolyte Microenvironments to Optimize the Activity and Selectivity for the Electrochemical Reduction of CO2 on Cu and Ag; Acc. Chem. Res. 2022, 55, 484−494. Dinh et al., CO2 electroreduction to ethylene via hydroxide-mediated copper catalysis at an abrupt interface; Science, (2018), 783-787, 360(6390). Star et a., Mass transport characterization of platinum group metal-free polymer electrolyte fuel cell electrodes using a differential cell with an integrated electrochemical sensor; Journal of Power Sources, (2020), 227655, 450.

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Montes-Cebrián, Yaiza, Albert Álvarez-Carulla, Jordi Colomer-Farrarons, Manel Puig-Vidal, and Pere Ll Miribel-Català. "Self-Powered Portable Electronic Reader for Point-of-Care Amperometric Measurements." Sensors 19, no. 17 (August 27, 2019): 3715. http://dx.doi.org/10.3390/s19173715.

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In this work, we present a self-powered electronic reader (e-reader) for point-of-care diagnostics based on the use of a fuel cell (FC) which works as a power source and as a sensor. The self-powered e-reader extracts the energy from the FC to supply the electronic components concomitantly, while performing the detection of the fuel concentration. The designed electronics rely on straightforward standards for low power consumption, resulting in a robust and low power device without needing an external power source. Besides, the custom electronic instrumentation platform can process and display fuel concentration without requiring any type of laboratory equipment. In this study, we present the electronics system in detail and describe all modules that make up the system. Furthermore, we validate the device’s operation with different emulated FCs and sensors presented in the literature. The e-reader can be adjusted to numerous current ranges up to 3 mA, with a 13 nA resolution and an uncertainty of 1.8%. Besides, it only consumes 900 µW in the low power mode of operation, and it can operate with a minimum voltage of 330 mV. This concept can be extended to a wide range of fields, from biomedical to environmental applications.

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Sharma, Preetam, Douglas Aaron, Lei Cheng, Jonathan Braaten, Nathan Craig, Christina Johnston, and Matthew M. Mench. "Localized Electrochemical Performance Degradation in Polymer Electrolyte Fuel Cells (PEFCs)." ECS Meeting Abstracts MA2022-02, no. 42 (October 9, 2022): 1571. http://dx.doi.org/10.1149/ma2022-02421571mtgabs.

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Pt electrocatalyst durability in polymer electrolyte fuel cells (PEFCs) is generally evaluated through an accelerated stress test (AST); for example, one AST features repeated square-wave cycling with H2/N2 between 0.6 V to 0.95 V vs. reversible hydrogen electrode (RHE) [1]. A separate triangular-wave AST with a higher potential range (1 – 1.5 V vs. RHE) assesses the durability of carbon-based supports [2]. Recent studies [3]–[5] have revealed the heterogeneous nature of cathode catalyst layer degradation. In general, Pt particle size growth mimics the flow field geometry with greater particle size growth under lands compared to channels. Additionally, growth is typically shown to be greater near the air outlet than the inlet and is assumed to be correlated to local performance decay. The impact of such localized degradation on distributed cell performance is investigated in this work. In the present study, a segmented cell is used to quantify functional dependence of local current distributions in aged samples to heterogeneous catalyst layer degradation (Pt particle size growth and carbon support corrosion). The outcome of this enhanced understanding is to identify limiting factors in cell performance at end-of-life (EOL). Single cell studies with 25-cm2 active area are performed using catalyst-coated Nafion® XL membranes (Ion Power Inc.) and SGL-22 BB gas diffusion layers (GDLs) as membrane electrode assembly (MEA) materials and 7-channel serpentine flow field. An S++® current scan shunt (CSS) sensor plate (25-cm2) with 100 current and 25 temperature measurement segments is utilized for current and temperature mapping, respectively. The MEAs are subjected to DOE’s square-wave cycling (0.6 to 0.95 V vs. RHE), triangular-wave cycling (1 to 1.5 V vs. RHE), and a sequence of square-wave cycling followed by triangular-wave cycling. Complete in-situ electrochemical characterization and post-mortem ex-situ diagnostics such as micro-X-ray diffraction (micro-XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) are used to obtain particle size distribution and spatial degradation profiles. Results indicate a strong dependence of current distributions on localized catalyst layer degradation. For example, MEA with relatively uniform current distributions at the beginning-of-life (BOL) in Figure 1 exhibits severe mass transport limitations (significantly higher current at the air inlet than the outlet) at EOL when subjected to triangular-wave carbon corrosion AST. Furthermore, an increase of ~1.5x in Tafel slope is observed for the aged sample at EOL, highlighting increased transport losses. These mass transport losses are believed to originate from loss of catalyst layer porosity and subsequent compaction due to carbon support corrosion [2]. This work seeks to achieve a greater understanding of the functional dependence between catalyst growth and carbon corrosion and observed local performance. References: [1] S. Stariha et al., “Recent Advances in Catalyst Accelerated Stress Tests for Polymer Electrolyte Membrane Fuel Cells,” J. Electrochem. Soc., vol. 165, no. 7, pp. F492–F501, 2018, doi: 10.1149/2.0881807jes. [2] N. Macauley et al., “Carbon Corrosion in PEM Fuel Cells and the Development of Accelerated Stress Tests,” J. Electrochem. Soc., vol. 165, no. 6, pp. F3148–F3160, 2018, doi: 10.1149/2.0061806jes. [3] L. Cheng et al., “Mapping of Heterogeneous Catalyst Degradation in Polymer Electrolyte Fuel Cells,” Adv. Energy Mater., vol. 2000623, pp. 1–7, 2020, doi: 10.1002/aenm.202000623. [4] P. Sharma et al., “Influence of Flow Rate on Catalyst Layer Degradation in Polymer Electrolyte Fuel Cells,” {ECS} Meet. Abstr., vol. {MA}2020-0, no. 36, p. 2345, Nov. 2020, doi: 10.1149/ma2020-02362345mtgabs. [5] K. Khedekar et al., “Probing Heterogeneous Degradation of Catalyst in PEM Fuel Cells under Realistic Automotive Conditions with Multi-Modal Techniques,” Adv. Energy Mater., 2021, doi: 10.1002/aenm.202101794. Figure 1

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Ge, Nan, Stéphane Chevalier, James Hinebaugh, Ronnie Yip, Jongmin Lee, Patrick Antonacci, Toshikazu Kotaka, Yuichiro Tabuchi, and Aimy Bazylak. "Calibrating the X-ray attenuation of liquid water and correcting sample movement artefacts duringin operandosynchrotron X-ray radiographic imaging of polymer electrolyte membrane fuel cells." Journal of Synchrotron Radiation 23, no. 2 (February 10, 2016): 590–99. http://dx.doi.org/10.1107/s1600577515023899.

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Synchrotron X-ray radiography, due to its high temporal and spatial resolutions, provides a valuable means for understanding thein operandowater transport behaviour in polymer electrolyte membrane fuel cells. The purpose of this study is to address the specific artefact of imaging sample movement, which poses a significant challenge to synchrotron-based imaging for fuel cell diagnostics. Specifically, the impact of the micrometer-scale movement of the sample was determined, and a correction methodology was developed. At a photon energy level of 20 keV, a maximum movement of 7.5 µm resulted in a false water thickness of 0.93 cm (9% higher than the maximum amount of water that the experimental apparatus could physically contain). This artefact was corrected by image translations based on the relationship between the false water thickness value and the distance moved by the sample. The implementation of this correction method led to a significant reduction in false water thickness (to ∼0.04 cm). Furthermore, to account for inaccuracies in pixel intensities due to the scattering effect and higher harmonics, a calibration technique was introduced for the liquid water X-ray attenuation coefficient, which was found to be 0.657 ± 0.023 cm−1at 20 keV. The work presented in this paper provides valuable tools for artefact compensation and accuracy improvements for dynamic synchrotron X-ray imaging of fuel cells.

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Elferink, Hidde, Jeroen P. J. Bruekers, Gerrit H. Veeneman, and Thomas J. Boltje. "A comprehensive overview of substrate specificity of glycoside hydrolases and transporters in the small intestine." Cellular and Molecular Life Sciences 77, no. 23 (June 6, 2020): 4799–826. http://dx.doi.org/10.1007/s00018-020-03564-1.

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AbstractThe human body is able to process and transport a complex variety of carbohydrates, unlocking their nutritional value as energy source or as important building block. The endogenous glycosyl hydrolases (glycosidases) and glycosyl transporter proteins located in the enterocytes of the small intestine play a crucial role in this process and digest and/or transport nutritional sugars based on their structural features. It is for these reasons that glycosidases and glycosyl transporters are interesting therapeutic targets to combat sugar related diseases (such as diabetes) or to improve drug delivery. In this review we provide a detailed overview focused on the molecular structure of the substrates involved as a solid base to start from and to fuel research in the area of therapeutics and diagnostics.

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Ding, Yi, and Mingwei Chen. "Nanoporous Metals for Catalytic and Optical Applications." MRS Bulletin 34, no. 8 (August 2009): 569–76. http://dx.doi.org/10.1557/mrs2009.156.

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AbstractNanoporous metals (NPMs) made by dealloying represent a class of functional materials with the unique structural properties of mechanical rigidity, electrical conductivity, and high corrosion resistance. They also possess a porous network structure with feature dimensions tunable within a wide range from a few nanometers to several microns. Coupled with a rich surface chemistry for further functionalization, NPMs have great potential for applications in heterogeneous catalysis, electrocatalysis, fuel cell technologies, biomolecular sensing, surface-enhanced Raman scattering (SERS), and plasmonics. This article summarizes recent advances in some of these areas and, in particular, we focus on the discussion of microstructure, catalytic, and optical properties of nanoporous gold (NPG). With advanced electron microscopy, three-dimensional tomographic reconstructions of NPG have been realized that yield quantitative characterizations of key morphological parameters involved in the intricate structure. Catalytic and electrocatalytic investigations demonstrate that bare NPG is already catalytically active for many important reactions such as CO and glucose oxidation. Surface functionalization with other metals, such as Pt, produces very efficient electrocatalysts, which have been used as promising fuel cell electrode materials with very low precious metal loading. Additionally, NPG and related materials possess outstanding optical properties in plasmonics and SERS. They hold promise to act as highly active, stable, and economically affordable substrates in high-performance instrumentation applications for chemical inspection and biomolecular diagnostics. Finally, we conclude with some perspectives that appear to warrant future investigation.

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Farooq, Muhammad, Muhammad Fayyaz Malik, Ashfaq Hussain, Majid Latif, Muhammad Usman Rathore, and Rehan Ahmad Khan Lodhi. "IMMUNOGENICITY AND SAFETY OF INACTIVATED SARS-COV-2 VACCINE (VERO CELL), BBIBP-CORV (SINOPHARM); AN OBSERVATIONAL STUDY FROM PAKISTAN." PAFMJ 71, no. 6 (December 30, 2021): 2024–28. http://dx.doi.org/10.51253/pafmj.v6i6.7034.

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Objective: To ascertain the immunogenicity and short-term safety of inactivated SARS-CoV-2 Vaccine (Vero Cell), BBIBPCorV (Sinopharm) in our setup. Study Design: Cross-sectional study. Place and Duration of Study: Combined Military Hospital Sialkot Pakistan, from Feb to Apr 2021. Methodology: A total of 227 health care workers (HCWs) between 18 to 59 years of age were included in the study. Two doses of Inactivated SARS-CoV-2 Vaccine (Vero Cell), BBIBP-CorV were administered to all individuals 21 days apart and they were monitored for any vaccine-related adverse reactions for 7 days after each dose. Neutralizing antibodies (NAbs) in study subjects were detected in three samples i.e. before 1st dose of vaccine, 21 days after 1st dose and 14 days after 2nd dose by Elecsys Anti- SARS-CoV-2 S (Roche Diagnostics). Results: Mean age of individuals in the study was 36.70 ± 18.08 years and most individuals were in the 31-45 years age group. Fatigue and drowsiness were the most common adverse effects experienced by study subjects after 1st and 2nd dose of the vaccine followed by malaise and headache. Only 42 (39%) individuals developed positive neutralizing antibody titers in a sample taken 21 days after 1st dose while all individuals except one (99%) developed positive neutralizing antibody titers in a sample taken 2 weeks after 2nd vaccine dose. Conclusion: Inactivated SARS-CoV-2 Vaccine (Vero Cell), BBIBP-CorV is safe and well-tolerated with very few adverse reactions. Immunogenicity was well achieved as the seroconversion rate was 99% two weeks after 2nd dose of the vaccine.

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Cheng, Lei, Morteza Rezaei Talarposhti, Kaustubh Khedekar, Jonathan Braaton, Iryna V. Zenyuk, Nathan Craig, and Christina Johnston. "(Invited) Insights of Electrochemical Degradation Enabled By Correlated in-Situ Electrochemical Diagnostics and Spatially Resolved Diffraction Mapping." ECS Meeting Abstracts MA2022-02, no. 56 (October 9, 2022): 2165. http://dx.doi.org/10.1149/ma2022-02562165mtgabs.

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One of the top priorities of human society is addressing climate change. Clean electrochemical technology is a vital part of the transformation necessary to meet climate goals and net-zero CO2 emissions by 2050. Electrochemical technology of high interest includes water electrolysis for green hydrogen generation, fuel cells for emission free transportation, and electrochemical CO2 reduction for achieving net-zero CO2 emissions. One critical challenge for wide-scale adoption of these electrochemical technologies is the long-term device durability. Comprehensive understanding the degradation phenomenon and underlying mechanism is of critical importance for technology and product development. In this regard, in-operando and in-situ techniques, providing unique and direct insight into the degradation process in these electrochemical devices, play important roles for advancing such understanding and ultimately increasing long-term durability. Such techniques often rely on combined electrochemical diagnostics with advanced spectroscopy or other imaging capable of temporal and spatial resolution. In-operando techniques are often challenging due to the need for unique electrochemical cell configurations that fulfill the requirements of the technique while at the same time delivering electrochemical behavior similar to a commercial device. The talk will first discuss a mapping methodology based on synchrotron X-ray micro-diffraction to study the heterogeneous degradation. Information obtained from the method and examples of application to study platinum catalyst degradation in accelerated stress tests will be discussed. The utility of correlating large datasets of in-situ electrochemical diagnostics from a variety of accelerated aging tests with the spatially resolved diffraction mapping will also be presented.

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Liu, Jiawei, Jonathan Braaten, Nicholas Tiwari, Xiaoxiao Wang, Scott Blackburn, Gerald Brown, Andrew M. Park, Zachary Ulissi, and Shawn Litster. "Evaluation of High Oxygen Permeability Ionomer (HOPI) Oxygen Permeability for Proton Exchange Membrane Fuel Cells (PEMFCs)." ECS Meeting Abstracts MA2022-02, no. 41 (October 9, 2022): 1514. http://dx.doi.org/10.1149/ma2022-02411514mtgabs.

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The performance of proton exchange membrane fuel cells (PEMFCs) is sensitive to Pt loading in the cathode catalyst layer, with lower Pt loadings significantly increasing the oxygen transport resistance of the catalyst-ionomer interface when using perfluorosulfonic acid (PFSA) ionomers. The oxygen permeability is suspected to be locally decreased at Pt interfaces due to ionomer densification caused by the Pt-ionomer interactions. However, due to the high cost of Pt, it is important to be able to reduce Pt loadings without increasing oxygen transport resistance. With this goal in mind, new precommercial high oxygen permeability ionomers (HOPIs) with blocky backbone units are being studied. These HOPIs show significantly lower local oxygen transport resistance in fuel cells as well as greater efficiency and durability. However, there was a question of whether HOPI’s higher in-situ oxygen permeability is due solely to reduced densification or if it is also due to increased bulk permeability of the films. Here we evaluated this question using a unique oxygen permeability measurement apparatus that measures the oxygen permeability of thin-films supported on mesoporous substrates. This apparatus allows films to be characterized without the polarized Pt surfaces used in other oxygen permeability diagnostics, providing insights into the bulk permeability of cast thin-films with minimized substrate effects. This presentation will present our findings of the oxygen permeability of pristine thin-film HOPIs characterized against that of the baseline PFSA ionomer. Results show that the HOPI is significantly more oxygen permeable than the baseline. This finding is supported by our molecular dynamics simulations of these ionomer films. This increased bulk film oxygen permeability indicates that a significant portion of the decreased oxygen transport resistance in the cathodes is associated with the greater bulk permeability of these films and not just local Pt interface effects. This material is based upon work supported by the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy (EERE) under the Fuel Cell Technologies Office, Award Number DE-EE0008822.

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Mughal, A., and X. Li. "Experimental diagnostics of PEM fuel cells." International Journal of Environmental Studies 63, no. 4 (August 2006): 377–89. http://dx.doi.org/10.1080/00207230600800670.

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Jacquemond, Rémy Richard, Maxime van der Heijden, Emre Burak Boz, Jeffrey A. Kowalski, Katharine Greco, Kitty Nijmeijer, Fikile R. Brushett, Pierre Boillat, and Antoni Forner-Cuenca. "Neutron Radiography As a Powerful Method to Visualize Reactive Flows in Redox Flow Batteries." ECS Meeting Abstracts MA2022-01, no. 48 (July 7, 2022): 2014. http://dx.doi.org/10.1149/ma2022-01482014mtgabs.

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Spatial and temporal gradients in reactant concentration, influenced by local microstructure and surface properties, govern the performance and durability of various advanced electrochemical systems. The cell and stack performance is typically assessed using traditional electrochemical diagnostics (e.g. polarization curves, electrochemical impedance spectroscopy) and the influence of materials is macroscopically evaluated based on empirical comparison of novel materials with the current state-of-the-art. While this is a valid approach to identify promising candidates, valuable information is lost due to the difficulty of identifying performance-limiting factors. Operando imaging of electrochemical systems, in tandem with complementary electrochemical diagnostics, has been instrumental in the development of advanced polymer electrolyte fuel cells1,2 and, more recently, lithium-ion batteries3,4. Over the past few years, several groups have developed novel imaging and spectroscopic techniques for operando characterization of redox flow batteries, which is the focus of this work. Wong et al. employed fluorescence microscopy and particle velocimetry to image concentration and velocity distributions near the electrode-flow field interface5. Tanaka et al. visualized flow distribution in redox flow batteries with infrared thermography6. Zhao et al. employed in-situ nuclear magnetic resonance to track reaction mechanisms occurring within the electrolyte7. Finally, several groups recently employed X-ray tomographic microscopy to visualize gas pockets within the liquid electrolyte imbibed porous electrode8–10. While these methods have provided important insights, an approach that enables quantitative mapping of species concentrations, in a non-invasive fashion and within an operating cell, has remained elusive. In this presentation, I will discuss our recent efforts to develop neutron radiography as an operando characterization method for non-aqueous redox flow batteries. We leverage the high attenuation of organic materials (i.e., high hydrogen content) in solution and, combined with isotopic labelling, we perform subtractive neutron imaging to quantify the concentration of active species and supporting electrolytes. To demonstrate the potential of this diagnostic tool, we characterize active species concentration distribution within a redox flow cell in a single electrolyte configuration with a non-aqueous electrolyte containing a TEMPO/TEMPO+ redox couple and study the influence of electrode microstructure, membrane type (e.g. porous or dense), and flow field design. To resolve the concentration profiles across the different layers, we employ the in-plane imaging configuration11 and correlate these concentration profiles to cell performance via polarization measurements under different operating conditions. In the final part of the talk, I will discuss our latest experimental campaign in which we investigated the use of energy-selective neutron radiography to deconvolute concentrations of active species and supporting electrodes during operation. References 1 P. Boillat, E. H. Lehmann, P. Trtik and M. Cochet, Curr. Opin. Electrochem., , DOI:https://doi.org/10.1016/j.coelec.2017.07.012. 2 J. Eller, T. Rosén, F. Marone, M. Stampanoni, A. Wokaun and F. N. Büchi, J. Electrochem. Soc., 2011, 158, B963. 3 B. Michalak, H. Sommer, D. Mannes, A. Kaestner, T. Brezesinski and J. Janek, Sci. Rep., 2015, 5, 15627. 4 D. P. Finegan, M. Scheel, J. B. Robinson, B. Tjaden, I. Hunt, T. J. Mason, J. Millichamp, M. Di Michiel, G. J. Offer, G. Hinds, D. J. L. Brett and P. R. Shearing, Nat. Commun., 2015, 6, 6924. 5 A. A. Wong, M. J. Aziz and S. Rubinstein, ECS Trans. , 2017, 77, 153–161. 6 H. Tanaka, Y. Miyafuji, J. Fukushima, T. Tayama, T. Sugita, M. Takezawa and T. Muta, J. Energy Storage, 2018, 19, 67–72. 7 E. W. Zhao, T. Liu, E. Jónsson, J. Lee, I. Temprano, R. B. Jethwa, A. Wang, H. Smith, J. Carretero-González, Q. Song and C. P. Grey, Nature, 2020, 579, 224–228. 8 R. Jervis, L. D. Brown, T. P. Neville, J. Millichamp, D. P. Finegan, T. M. M. Heenan, D. J. L. Brett and P. R. Shearing, J. Phys. D. Appl. Phys., , DOI:10.1088/0022-3727/49/43/434002. 9 F. Tariq, J. Rubio-Garcia, V. Yufit, A. Bertei, B. K. Chakrabarti, A. Kucernak and N. Brandon, Sustain. Energy Fuels, 2018, 2, 2068–2080. 10 K. Köble, L. Eifert, N. Bevilacqua, K. F. Fahy, A. Bazylak and R. Zeis, J. Power Sources, , DOI:10.1016/j.jpowsour.2021.229660. 11 P. Boillat, D. Kramer, B. C. Seyfang, G. Frei, E. Lehmann, G. G. Scherer, A. Wokaun, Y. Ichikawa, Y. Tasaki and K. Shinohara, Electrochem. commun., 2008, 10, 546–550.

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Balashova, E. A., L. I. Mazur, and N. P. Persteneva. "Diagnostic value of reticulocyte hemoglobin equivalent to confirm iron deficiency in full-term infants." Rossiyskiy Vestnik Perinatologii i Pediatrii (Russian Bulletin of Perinatology and Pediatrics) 65, no. 3 (July 8, 2020): 44–52. http://dx.doi.org/10.21508/1027-4065-2020-65-3-44-52.

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Diagnostics of Iron deficiency anemia (IDA) in outpatient pediatric practice is often based on decreased hemoglobin level. Latent iron deficiency diagnostic is not a part of current routine practice.Objective. To study the diagnostic value of red blood cell indices and reticulocyte hemoglobin equivalent in diagnostics of iron deficiency in full-term infants.Children characteristics and research methods. A prospective cohort study of healthy full-term children aged from 6 to 12 months at the children hospitals of Samara and Tolyatti. The laboratory examination included a general blood test to determine the concentration of hemoglobin, the number of red blood cells, red blood cell indices, and reticulocyte hemoglobin equivalent (Ret-He); to determine serum ferritin and C-reactive protein. The AUC (area under the curve) was used to determine the diagnostic value of quantitative indicators. The children with anemia without iron deficiency and children who received iron supplements within 1 month prior to laboratory examination were excluded from the analysis.Results. The study involved 207 children. When diagnosing iron deficiency in children, the highest AUC was found in Ret-He: 0.747 [0.679; 0.816] in 6-months-old children and 0.790 [0.708; 0.871] in 1-year-old children. The Ret-He diagnostic value was higher in children with iron deficiency: AUC 0.826 [0.754; 0.898] in 6- months-old children and 0.865 [0.809; 0.920] in 1-year-old children.Conclusion. Ret-He is a better predictor of iron deficiency in children under 1 year as compared to the red blood cell indices. The diagnostic value of red blood cell indices and Ret-He is higher in case of iron deficiency anemia than in case of iron deficiency conditions.

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Kahia, Hichem, Saadi Aicha, Djamel Herbadji, Abderrahmane Herbadji, and Said Bedda. "Neural Network based Diagnostic of PEM Fuel Cell." Journal of New Materials for Electrochemical Systems 23, no. 4 (December 31, 2020): 225–34. http://dx.doi.org/10.14447/jnmes.v23i4.a02.

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This paper focuses in finding a suitable, effective, and easy to use method, to avoid the frequent mistakes that are presented by the poor flow of water inside the fuel cell during its operation. Towards this aim, the artificial intelligence technology is proposed. More specifically, a neural network model is used to enable monitoring the influence of the humidity content of the fuel cell membrane, through employing electrochemical impedance spectroscopy method (EIS analysis). This technique allows analyzing and diagnosing PEM fuel cell failure modes (flooding & drying). The benefit of this work is summed up in the demonstration of the existence in a simple way that helps to define the state of health of the PEMFC.

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50

WATANABE, Takao, and Yoshiyuki IZAKI. "Diagnostic method on molten carbonate fuel cell operation." NIPPON KAGAKU KAISHI, no. 8 (1988): 1334–39. http://dx.doi.org/10.1246/nikkashi.1988.1334.

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Journal articles on the topic 'Fuel cell diagnostics'

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