Дисертації з теми "Membrane échangeuse de proton"
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He, Chen Feng. "Surface behavior of sulfonated hydrocarbon proton exchange membranes." Doctoral thesis, Université Laval, 2018. http://hdl.handle.net/20.500.11794/31224.
The fuel cell has received attention as a promising eco-friendly alternative energy source to fossil fuels. Polymer exchange membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs) have attracted increasing interest for use in motor vehicles and electronic applications including stationary and portable devices. As a key component of PEMFC and DMFC, PEM is required to perform multiple functions such as fuel separator, electrical insulator and ionic path to transport protons from the anode to the cathode. The presence of water in PEM is essential for traditional, sulfonated polymers to transfer protons and to facilitate proton conductivity. As Nafion, the proton conduction of the sulfonated PEM-type polymers depends upon the water content in the membranes. However, excessive water uptake in a PEM results in unacceptable dimensional change, dimensional mismatch with the electrodes, delaminating of catalyst layers from the PEM and loss of mechanical properties, which could result in poor membrane electrode assembly (MEA) performance or durability. As a highly integrated system, fuel cells are used in a heterogeneous environment containing gas, liquid, and solid. Typically, MEAs are constructed by bonding carbonsupported platinum catalyst electrodes onto the PEM electrolyte. Regardless of the PEM used, a Nafion-type ionomer is usually employed as a catalyst support. The structure and activity at the different interfaces, the adhesion and compatibility among various layers, as well as fuel property on PEM play key roles on the fuel cell universal performance as vital as the individual components. Among these heterogeneous concerns, crossover of methanol in PEM, such as Nafion, limits DEMFC applications. In spite of the development of numerous hydrocarbon PEMs as substitutes to Nafion, the surface behavior and interfacial match between a PEM and the other layers, such as, the interface between a PEM and gas diffusion layer/catalyst layer/methanol layer are less understood. In this thesis, the surface/interface behavior of a representative selection of hydrocarbon-based proton exchange membranes (PEMs) was investigated. These PEMs are: copolymerized sulfonated poly(ether ether ketone) (SPEEK-HQ), sulfophenylated poly(aryl ether ether ketone) (Ph-SPEEK), sulfophenylated poly(aryl ether ether ketone ketone) (Ph-m-SPEEKK), and sulfonated poly (aryl ether ether nitrile) (SPAEEN-B).
Mabrouk, Walid. "Synthèse et caractérisation de nouvelles membranes protoniques : Applications en pile à combustible à membrane échangeuse de protons." Phd thesis, Conservatoire national des arts et metiers - CNAM, 2012. http://tel.archives-ouvertes.fr/tel-00697008.
Bressel, Mathieu. "Modélisation raphique pour le pronostic robuste de pile à combustible à membrane échangeuse de proton." Thesis, Lille 1, 2016. http://www.theses.fr/2016LIL10119/document.
The fuel cell (FC) is at present the alternative solution to the fossil fuels the most promising. It is however advisable to improve its reliability. This requires the implementation of algorithms capable of estimating in real time the state of health and forecasting its remaining useful life (prognostics). The methods of prognostics based on a physical model offer precise results once they do not requiring either learning or expertise of the operator. However, the problem for a FC system lies in the coupling of several physical phenomena, the uncertainty of the parameters of the model and the low instrumentation of the FC stack.Thus, we use uncertain models based on the Bond Graph tool well adapted for the FC. Concretely, the parameters uncertainties are integrated in the model of evolution of the powers which is used for the detection of the beginning of the aging and the estimation of the degradation of the FC based on the causal and structural properties of the model. The generated model of degradation is used by an extended Kalman filter which allows the estimation of the state of health , the dynamics of the aging and the quantification of the uncertainty for any operating condition (of temperature, current and pressure). An Inverse First Order Reliability Method is then used for the prediction of the remaining useful life and the inherent uncertainty. The global method was validated on various sets of experimental data. Thanks to this set of tools, a control based on the inversion of an Energetic Macroscopic Representation (EMR) model with time varying parameters, robust to aging is developed based on the state of health estimation
Wu, Yiming. "Long term performance prediction of proton exchange membrane fuel cells using machine learning method." Thesis, Belfort-Montbéliard, 2016. http://www.theses.fr/2016BELF0308/document.
The environmental issues, especially the global warming due to greenhouse effect, has become more and morecritical in recent decades. As one potential candidate among different alternative "green energy" solutions forsustainable development, the Proton Exchange Membrane Fuel Cell (PEMFC) has been received extensiveresearch attention since many years for energy and transportation applications. The PEMFC stacks, can produceelectricity directly from electrochemical reaction between hydrogen and oxygen in the air, with the only by-productsof water and heat. If the hydrogen is produced from renewable energy sources, this energy conversion is 100% ecofriendly.However, the relatively short lifespan of PEMFCs operating under non-steady-state conditions (for vehicles forexample) impedes its massive use. The accurate prediction of their aging mechanisms can thus help to designproper maintenance patterns of PEMFCs by providing foreseeable performance degradation information. In addition,the prediction could also help to avoid or mitigate the unwanted degradation of PEMFC systems during operation.This thesis proposes a novel data driven approach to predict the performance degradation of the PEMFC using animproved relevance vector machine method.Firstly, the theoretical description of the PEMFC during operation will be presented followed by an extensivelydetailed illustration on impacts of operational conditions on PEMFC performance, along with the degradationmechanisms on each component of PEMFC. Moreover, different approaches of PEMFC performance prediction inthe literature will also be briefly introduced.Further, a performance prediction method using an improved Relevance Vector Machine (RVM) would be proposedand demonstrated. The prediction results based on different training zones from historical data will also bediscussed and compared with the prediction results using conventional Support Vector Machine (SVM).Moreover, a self-adaptive kernel RVM prediction method will be introduced. At the meantime, the design matrix ofthe RVM training will also be modified in order to acquire higher precision during prediction. The prediction resultswill be illustrated and discussed thoroughly in the end.In summary, this dissertation mainly discusses the analysis of the PEMFC performance prediction using advancedmachine learning methods
Sutor, Anna. "Étude des relations entre les performances électrochimiques des membranes ionomères pour piles à combustible et leur état d'hydratation : apport des spectroscopies vibrationnelles in situ." Thesis, Montpellier, Ecole nationale supérieure de chimie, 2013. http://www.theses.fr/2013ENCM0012.
The water content of polymer electrolytes for Proton Exchange Membrane Fuel Cells and, thus, their proton conductivity, is the key issue to understand and to explain the electrochemical performances of the PEMFC electrochemical device. The fuel cell operation (creation, absorption, diffusion, migration and desorption of water) leads the hydration state of the membrane strongly heterogeneous. The proton conductivity of state-of-art polymer electrolytes results from the material structure, the water and proton diffusion mechanisms and the interactions between water and the polymer phase within the membrane. This work deals with these issues and uses vibrational spectroscopy techniques (Infra-Red and Raman) to study hydration and diffusion phenomena. Among others, this work shows the contribution of in-situ vibrational spectroscopies to the understanding of the water management issue and relationships between the water distribution throughout the membrane and the fuel cell electrochemical performances. Two perfluorosulfonated polymers, Nafion and Aquivion, are investigated.The water absorption and diffusion properties of these two membranes are studied under several hydration conditions: at the equilibrium, under external gradient of the water chemical activity and under the effect of an electric gradient (in-situ and operando measurements with the working fuel cell).Infrared spectroscopy is used to study structural modifications of the polymer phase occurring during the hydration process as well as the confinement state of water sorbed within the membrane. The last is submitted to different water vapor pressures and temperatures. This spectroscopy also allows to study interactions between water and the different chemical groups belonging to the polymer structure. Results are used to describe water absorption as well as the proton dissociation mechanism involving the sulfonic groups.Confocal Raman Micro-spectroscopy allows, by the spatial resolution at the micrometric scale, to probe the thickness of the membrane and to measure the inner, through-plane, water gradient. A micro-fluidic cell has been developed for the study of diffusion transport phenomena. This method is currently the only one by which equivalent diffusion coefficients can be calculated from internal water concentration gradients.A fuel cell especially designed for Raman measurements allowed us, for the first time by means of this technique, to determine the water distribution through the thickness of the membrane working in the electrochemical device. The new insights so obtained are essential for understanding, explaining and predicting the effects of the heterogeneous water distribution throughout the fuel cell heart on the electrochemical behavior
Yakisir, Dinçer. "Development of gas diffusion layer for proton exchange membrane fuel cell, PEMFC." Master's thesis, Université Laval, 2006. http://hdl.handle.net/20.500.11794/18765.
Bultel, Yann. "Modélisation des couches actives d'électrodes volumiques de piles à combustible à membrane échangeuse de protons." Grenoble INPG, 1997. http://www.theses.fr/1997INPG0054.
Cherragui, Mohamed. "Développement d'un simulateur Hardware-in-the-Loop (HIL) d'un système pile à combustible à membrane échangeuse de proton." Thesis, Bourgogne Franche-Comté, 2017. http://www.theses.fr/2017UBFCD034.
The fuel cell is a source of energy that generates electricity from hydrogen and oxygen.They are very promising candidates for the production of electric power.Nevertheless, the fuel cell still suffers from imperfections limiting its commercialization on a full scale, in particular for transport applications.This is the reason why, hybridization of different energy sources has become a reality for non-stationary applications such as all-electric vehicles.However, these applications require reliable energy management solutions that take into account all the constraints of the hybrid electrical system.Therefore, the development of validation platform is necessary.In this context, the Hardware In the Loop (HIL) is a very promising technique, where part of a real system can be replaced by a virtual system while respecting the communication between these physical and virtual subsystems.This document details the dynamic models of a proton exchange membrane fuel cell (PEMFC) associated with supercapacitors.Furthermore, the energy management between these two sources and the prognostic of the fuel cell composed of a extenced Kalman Filter filter (EKF) for the estimation of the real state of health (SoH) of the stack and, on the other hand, of the Inverse First Order Reliability Method (IFORM) in order to estimate the remaining useful life of the stack, all implemented in an FPGA control board in a Hardware-In-The-Loop (HIL) context
Tran, Thi Bich Hue. "Gestion de l’eau dans les piles à combustible électrolyte polymère : étude par micro-spectroscopie Raman operando." Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTT198/document.
In a proton exchange membrane fuel cell (PEMFC), the performance and the durability of the system is directly related to the water management in the membrane electrode assembly (AME), particularly in the membrane electrolyte. The optimization of the water repartition, homogeneous and sufficient, is therefore essential to obtain good performance and great durability. The water management in the membrane depends both on the operating conditions and the gas flow-field design. However, the effect of these parameters is not yet fully understood despite numerous studies.In this context, the first part of this thesis focuses on the influence of gas humidification and operating temperature conditions on the performance and the water distribution in a serpentine flow-field cell. The inner water profiles across the membrane thickness at the center of the active surface are recorded by Raman spectroscopy operando. The relationship between the water distribution and the performance of the cell will be discussed. In the second part, the performance and the water distribution in a parallel flow-field cell are studied under the same temperature conditions applied for the serpentine flow-field cell. The results obtained allow us to directly compare the behavior of these two configurations. The origin of their water distribution and performance differences will be discussed. In the third part, we focus on the distribution of water in the plane of a serpentine flow-field cell at different operating temperatures. The cell is powered in counter-flow. The inner water profiles in the membrane are recorded for three zones: inlet, center and outlet. We then trace the water repartition on the cathodic and anodic interfaces. This information gives us a better understanding of the counter-flow effect on the water distribution in the plane of the serpentine flow-field cell
Gloaguen, Frédéric. "Piles à combustible à membrane échangeuse de protons : contribution à l'étude de la cathode à oxygène." Grenoble INPG, 1994. http://www.theses.fr/1994INPG0105.
Campagne, Benjamin. "Nouveaux copolymères fluorés porteurs de fonctions azole (imidazole, benzimidazole ou triazole) pour membranes pour piles à combustible (PEMFC) fonctionnant en conditions quasi-anhydres." Thesis, Montpellier, Ecole nationale supérieure de chimie, 2013. http://www.theses.fr/2013ENCM0006.
This work concerns the syntheses and characterizations of new proton exchange polymer membranes containing N-heterocyclic compounds for PEMFC working under low relative humidity (HR < 25 %) and temperatures up to 200 °C for automotive applications. Three new partially fluorinated copolymers bearing different azole compounds (imidazole, benzimidazole or 1H-1,2,4-triazole) as pendant groups have been synthesized and characterized. Then, they have been used to synthesize blend polymer membranes with s-PEEK (20 µm < thickness < 100 µm) that showed thermal stabilities up to 210 °C. These new families of membranes have been compared and highest proton conductivity values have been observed for 1H-1,2,4-triazole containing membranes (σ = 7,0 mS.cm-1, 140 °C, HR < 25 %). Mechanical properties and oxidative stability of these membranes have been assessed and showed similar values than main commercially available membranes. To improve membranes structuration, pseudo semi-interpenetrating polymer networks have been synthesized. Thus, original cross-linkable terpolymers bearing 1H-1,2,4-triazole and cyclocabonate functions as pendant groups have been synthesized and blended with s-PEEK as linear polymer to synthesize new polymers membranes (20 µm < thickness < 60 µm). Cross-linking has been carried from the cyclocarbonate/diamine reaction to get pseudo semi-interpenetrated polymer networks. Finally, both pseudo semi-interpenetrated polymer networks and uncross-linked membranes were doped by immersion in phosphoric acid solution to increase proton conductivity of these materials. Single cell fuel cell tests have been carried out and showed good performances. High temperatures (140 – 180 °C) proton conductivity values of these doped membranes have been estimated from extrapolation curves and reached up to 210 and 250 mS.cm-1, at 180 and 200 °C, HR < 25 %, respectively (extrapolated values). Proton conductivity values should be assessed at these targeted temperatures (140 to 200 °C)
Cognard, Gwenn. "Electrocatalyseurs à base d’oxydes métalliques poreux pour pile à combustible à membrane échangeuse de protons." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAI007.
Conventional electrocatalysts used in proton exchange membrane fuel cells (PEMFC) are composed of platinum nanoparticles supported on high specific surface area carbon blacks. At the cathode side of the PEMFC, where the oxygen reduction reaction (ORR) occurs, the electrochemical potential can reach high values - especially during startup-shutdown operating conditions - resulting in irreversible degradation of the carbon support. A “material” solution consists of replacing the carbon with supports based on metal oxides. The latter have to be resistant to electrochemical corrosion, be electronic conductor and have a porous and nano-architectural structure (for the transport of reagents and products and the homogeneous distribution of the ionomer and platinum nanoparticles).In this work, we have developed and characterized electrocatalysts composed of platinum (Pt) nanoparticles based on tin dioxide (SnO2) and titanium dioxide (TiO2) with optimized textural (aerogel, nanofibres or loosetubes morphologies) and electron-conduction properties (doped with niobium Nb or antimony Sb). The best electrocatalytic properties are reached for an antimony-doped SnO2 aerogel support, denoted ATO. The Pt/ATO electrocatalyst has especially a higher specific activity for the ORR than a Pt/carbon Vulcan® electrocatalyst, synthesized in the same conditions, suggesting beneficial interactions between the Pt nanoparticles and the metal oxide support (Strong Metal Support Interactions SMSI).Durability tests simulating automotive operating conditions of a PEMFC were carried out in liquid electrolyte at 57 °C on these two electrocatalysts by cycling between 0.60 and 1.00 V vs the reversible hydrogen electrode (RHE) or between 1.00 and 1.50 V vs RHE. The Pt/ATO electrocatalyst has an increased stability compared to the reference Pt/carbon Vulcan® electrocatalyst. However, new degradation mechanisms were highlighted in this study: first, the doping element (Sb) is progressively dissolved during electrochemical ageing, which implies a loss of electronic conductivity. This loss is partly due to incursions at low potential, including during electrochemical characterizations. Moreover, between 5,000 and 10,000 cycles of the accelerated stress tests (between 0.60 and 1.00 V vs RHE or between 1.00 and 1.50 V vs RHE at 57 °C), the support loses its porous structure and forms a poorly conductive amorphous film
Nabil, Yannick. "Supports de Catalyseur Nanostructurés pour Pile à Combustible à Membrane Échangeuse de Protons." Thesis, Montpellier, Ecole nationale supérieure de chimie, 2015. http://www.theses.fr/2015ENCM0029/document.
One pivotal issue to be overcome for the widespread adoption of Proton exchange membrane fuel cells (PEMFC) is the stability overtime. In this context, This PhD project focuses on the elaboration of niobium carbide based electrocatalyst supports for the PEMFC cathode to replace the conventional carbon based supports that notoriously suffer from corrosion in fuel cell operating conditions. The approach is to associate this alternative chemical composition with controlled morphologies in order to design electronically conductive and chemically stable materials with the appropriate porosity. Three different syntheses involving hydrothermal template synthesis or electrospinning have been developed leading to three different morphologies: nanostructured powders with high surface area, self-standing nanofibrous mats, and nanotubes with porous walls. These various supports have been catalysed by deposition of platinum nanoparticles synthesised by a microwave-assisted polyol method, and they have been characterised for their chemical and structural composition, morphology, and electrochemical properties. This work demonstrates that the Pt loaded NbC supports feature a greater electrochemical stability than a commercial Pt/C reference and similar electrocatalytic activities towards the oxygen reduction reaction
Mezzi, Rania. "Contrôle tolérant au vieillissement dans des systèmes pile à combustible PEMFC." Thesis, Bourgogne Franche-Comté, 2019. http://www.theses.fr/2019UBFCD031.
The objective of this work is to realize an aging-tolerant control for a proton exchange membrane fuel cell system (PEMFC). In order to achieve this goal, supervision tools, including the monitoring of critical variables, the state of health evaluation and the prediction of the future state are studied and realized. The information collected are used to adapt the system control strategy. The priority of the monitoring system developed is to ensure the energy supply required by the user, while ensuring minimal degradation of the fuel cell. The work consists on determining optimal temperature values, cathode and anode stoichiometry coefficients, and fuel cell current to provide the power required by the load, while extending the lifetime of the PEMFC. The proposed strategy avoids reversible damage and slows the aging rate of the components, while maintaining the value of the voltage in an optimal and low degrading operating range. This voltage variation range was determined by studying the degradation mechanisms of PEMFC
Zhao, Zuzhen. "Détermination des mécanismes de dégradation d'électrodes modèles de pile à combustible à membrane échangeuse de protons." Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00764891.
Massonnat, Pierre. "Développement d'un modèle multi physique multidimensionnel de pile à combustible à membrane échangeuse de proton en temps réel pour système embarqué." Thesis, Belfort-Montbéliard, 2015. http://www.theses.fr/2015BELF0268/document.
The fuel cell is an electric generator which uses an electrochemical effect discovered in 18 century by ChristianSchönbein. This technology has gotten successively periods of development and periods of void in the pastdecades. After the petrol barrel price rising and the people¿s awareness of environmental problem such asgreenhouse effect, the research in fuel cell field has been increasing constantly. Its higher efficiency compared tothermal technology to produce electricity, the possibility to use no fossil fuel and no pollution final products make thefuel cell an attractive substitution candidate for energy production. However, its cost, life time, power density andother problems related to the fuel storage do not allow it to replace immediately the actual technology which is elderand benefit about scale economy effect. Thus, the fuel cell technology must be improved to become economicallyviable.One of the ways to do it, is to model the fuel cell in order to reflect, analyze and better understand its behavior with aminimal cost. Unfortunately, the fuel cell is a complex system which combines fluidic, thermic and electrochemicaleffects. In literature, many one dimensional real time models have been developed. But to analyze and predict localphenomena, a 2 dimensional model is needed. However, the general two dimensional models use finite elementcalculation methods that cannot be done in real time due to their complex mathematical calculation. In spirit toovercome this calculation complexity problem, the challenge of this thesis is defined: develop a 2 dimensional modelwho are able to be executed in real time on an ordinary computer or an embedded system.In order to achieve the desired real time performance, the physical, mathematical and computer concepts of realtime 2D fuel cell model are developed, combined and integrated with specific organization methods in a C languageprogram which does not requires an important calculation power or memory to run. All the modeling assumptionsand the modified mathematic methods are implanted following an innovative modeling approach.Finally, a 2D, multiphysique, multidimensional real time fuel cell model is developed and its parameters are adjustedwith a real fuel cell stack from different experiments. The results are then analyzed with a structured observationmethod with conclusions given at last
Carrère, Pierre. "Modelling and numerical simulation of water transfer in Proton Exchange Membrane Fuel Cells." Thesis, Toulouse, INPT, 2019. http://www.theses.fr/2019INPT0123.
Water management is considered as a key issue in order to improve Proton Exchange Membrane Fuel Cells efficiency and durability. One of the critical components regarding this issue is the athode Gas Diffusion Layer (GDL). In this context, the main goal of the PhD work is to improve the understanding of the mechanisms responsible for the liquid water formation and transport in the cathode GDL. To this end, a Mixed liquid-vapour Injection Pore Network Model (MIPNM) is developed. This new model enables one to simulate the liquid water formation and transport in the cathode GDL for a larger range of operating conditions (temperature, current density and channel relative humidity) than in previous works. Different regimes of water formation and transport are identified and described. In a second part, the PhD work focus on the impact of the GDL hydrophobic treatment. Currently commercialized GDLs are rendered hydrophobic by coating Polytetrafluoroethylene (PTFE) onto the hydrophilic carbon fibres. It has been reported that the coating can be nonuniform on fresh GDLs and also that the coating can be altered during the operation of the fuel cell. The impact of these two phenomena on the liquid water distribution and on the reactant gas access to the catalyst layer is studied using the MIPNM for mixed wettability networks. In a third part, a work aiming at the improvement of PEMFC efficiency is developed. The goal is to optimise the reactant gas access to the catalyst layer by modifying the microstructure of GDLs. This is performed by coupling the PNM with a genetic algorithm. In a complementary study, the improvement of the reactant gas access is studied through modifications of the GDL wettability properties. Finally, a 1D model of the whole anode-cathode assembly is developed so as to take into account both anode and cathode operating conditions. This 1D model is coupled with the MIPNM in order to assess the impact of the anode operating conditions on the liquid water distribution in the cathode GDL
Castanheira, Luis Filipe Rodrigues. "Corrosion of high surface area carbon supports used in proton-exchange membrane fuel cell electrodes." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENI084/document.
This thesis investigates the degradation mechanism of high surfacearea carbon (HSAC) supports used in proton-exchange membrane fuel cell (PEMFC) electrodes. The structural and the chemical properties of different HSAC supports were established. The effectof the Nafion® ionomer used as a proton conductor, the gas atmosphere, the upper potential limit and the intermediate electrochemical characterizations used to monitor the changes ofthe electrochemical surface area during accelerated stress tests(ASTs) were investigated. The long-term physical and chemical changes of Pt/HSAC electrocatalysts were investigated insimulated PEMFC operating conditions. Using Raman spectroscopy, we showed that the COR is strongly structure sensitive and proceeds more rapidly on disordered domains of the HSAC (amorphous carbon and defective graphite crystallites) thanon graphitic domains. The coverage with carbon surface oxides was investigated with X-ray photoelectron spectroscopy and bridged tothe intensity of the quinone/hydroquinone (Q/HQ) peak monitored by cyclic voltammetry. Finally, the analyses realized on membrane electrode assemblies operated for 12,860h disclosed a perfect agreement between model and real PEMFC operating conditions, and confirmed the structural dependency of the COR kinetics
Zhou, Daming. "Modeling and Multi-Dimensional Analysis of a Proton Exchange Membrane Fuel Cell." Thesis, Bourgogne Franche-Comté, 2017. http://www.theses.fr/2017UBFCA011/document.
Before mass commercialization of proton exchange membrane fuel cell, the research on the design of appropriate control strategies and auxiliaries need to be done for achieving proton exchange membrane fuel cell (PEMFC) optimal working modes. An accurate mathematical PEMFC model can be used to observe the internal variables and state of fuel cell during its operation, and could further greatly help the system control strategy development.A comprehensive multi-physical dynamic model for PEMFC is developed in chapter I. The proposed model covers multi-physical domains for electric, fluidic and thermal features. Particularly, the transient phenomena in both fluidic and thermal domain are simultaneously considered in the proposed model, such as the dynamic behaviors of fuel cell membrane water content and temperature. Therefore, this model can be used to analyze the coupling effects of dynamic variables among different physical domains.Based on the developed multi-physical PEMFC model, a full two-dimensional multi-physical model is further presented. The proposed model covers electrical and fluidic domains with an innovative 2-D modeling approach. In order to accurately describe the characteristics of reactant gas convection in the channels and diffusion through the gas diffusion layer, the gas pressure drop in the serpentine pipeline is comprehensively analyzed by fully taking the geometric form of flow field into consideration, such as the reactant gas pressure drop due to the pipeline sharp and U-bends. Based on the developed 2-D fluidic domain modeling results, spatial physical quantity distributions in electrical domain can be further obtained. Therefore, this 2-D PEMFC model can be use to study the influences of modeling parameters on the local multi-dimensional performance prediction. The simulation and experimental test are then performed to validate the proposed 2-D model with a commercial Ballard NEXA 1.2 kW PEMFC stack.In chapter II, analyses of dynamic phenomena step responses are conducted based on the developed multi-physical dynamic PEMFC model using the relative gain array (RGA) method for various control input variables, in order to quantitatively analyze the coupling effects in different physical domains, such as the interactions of membrane water content and temperature. Based on the calculated values of relative gain array, the proposed model can be considered as a fuel cell MIMO system, which could be divided into two independent control sub-systems by minimizing parameter coupling effects between each other. Due to the closely coupled parameters in the proposed first control sub-system, a decoupling control method is recommended to achieve optimized control results. The coupling analysis presented in this thesis can help engineers to design and optimize the fuel cell control strategies, especially for the water and thermal management in fuel cell systems
Toudret, Pierre. "Compréhension et optimisation des couches actives de pile à combustible à membrane échangeuse de protons." Electronic Thesis or Diss., Université Grenoble Alpes, 2023. http://www.theses.fr/2023GRALI124.
The Proton Exchange Membrane Fuel Cell (PEMFC) is an electrochemical converter that produces electricity, heat and water from the oxidation of hydrogen and reduction of oxygen. This efficient and greenhouse gas-free technology is a promising candidate for reducing CO2 emissions, particularly in heavy-duty transportation applications (trucks, buses, etc.). Catalyst layers are the seat of electrochemical reactions and thus the electrodes of the PEMFC. They determine the performance, cost and durability of the fuel cell. Catalyst layers are porous layers composed of nanostructured catalyst particles bound by a proton-conducting polymer, the ionomer. The catalyst layer is obtained by drying, after coating, an ink consisting of a dispersion of catalyst particles and ionomer in one or more solvents. It has been shown that the performance of the catalyst layer depends on manufacturing parameters such as catalyst layer composition, ink solvent type, deposition and assembly process with other PEMFC components. In this work, the structural characterization of the ionomer in the catalyst layer will provide a better understanding of the relationships between its fabrication and operation
Yin, Liangzhen. "Intelligent control for performance optimization of proton exchange membrane fuel cell system." Electronic Thesis or Diss., Bourgogne Franche-Comté, 2023. http://www.theses.fr/2023UBFCA013.
Proton exchange membrane fuel cell (PEMFC) system has been considered as the new power generation technology as it has the advantage of high power density, zero emission, high efficiency, and fast start-up characteristics. Therefore, this thesis is devoted to researching system integration, system parameter trcking control, and system performance optimization for open-cathode and closed-cathode PEMFC systems. For open-cathode PEMFC system, the stack temperature is the key factor sffecting the output performance of the system. In order to improve the dynamic temperature tracking performance under load changing conditions, adaptive inverse control and grey prediction based model free adaptive control is proposed for optimal temperature control of system. Further, in order to enhance the system efficiency of system, a maximum efficiency control strategy based on maximum efficiency optimization and constraint generalized predictive control is proposed in this thesis. For closed-cathode PEMFC system, considering the existed nonlinearity and strong coupling between operating parameters such as stack temperature and oxygen excess ratio (OER), a dual loop multivariable control strategy based on MIMO model free adaptive sliding mode control is proposed for stack temperature and air flow rate regulation of closed-cathode PEMFC system. Moreover, a 300 W open-cathode PEMFC system test bench and a 5-kW closed-cathode PEMFC system tests bench are established. All the control strategies and the performance optimization strategies are verified on the established test bench of open-cathode and closed-cathode PEMFC systems
Otmani, Nassim. "Détermination des contraintes mécaniques dans les membranes Nafion® au cours du fonctionnement en pile à combustible." Grenoble INPG, 2009. http://www.theses.fr/2009INPG0117.
The durability of proton exchange membrane fuel cells is still not sufficient to be compatible with large-scale applications. The work of this PhD aims at determining the mechanical streses endured by the Nafion® membranes during the PEMFC operation. The elastoplastic properties of Nafion® have been measured in the PEMFC hygrothermal conditions, thanks to tensile tests. In the same conditions, the swelling has been investigated. A link between structure, water content, swelling and mechanical stresses has also highlighted. These properties have then been incorporated in a model built to describe the PEMFC mechanical behaviour. After an experimental validation, this model has been used to simulate hygrothermal loadings representative of the real-life PEMFC operation. A parametric study has given the possibility to advocate some technical advises in order to minimize the mechanical stresses within the membrane
Woo, Sahng Hyuck. "Membranes composites acide perfluorosulfonique (PFSA)/argile pour un fonctionnement à faible humidité relative et haute température des piles à combustible à membrane échangeuse de protons (PEMFC)." Thesis, Paris Sciences et Lettres (ComUE), 2019. http://www.theses.fr/2019PSLEM033.
This thesis introduces novel electrolyte membranes which can be operated at low relative humidity (below 50%) and intermediate temperature, i.e., 90℃. More specifically, the thesis takes benefit from hygroscopicity of microfibrous SEP (sepiolite) and tubular HNT (halloysite). Changes in Nafion membrane properties with blending time were studied. Moreover, these nanoclays are functionalized and pretreated to make them proton conductive and to improve their compatibility with short-side-chain PFSA (perfluorosulfonic acid) composite membranes based on Aquivion. To begin with, functionalized and pretreated clay nanoparticles are characterized prior to incorporation in polymer matrix: ATR-FTIR (attenuated total reflection-fourier transform infrared spectroscopy), Py-GC/MS (pyrolysis gas chromatography mass spectrometry), and TGA (thermogravimetric analysis). Composites membranes have them been prepared and characterized for proton conductivity, water uptake, swelling, thermo-mechanical strength and chemical stability. The dispersion state of SEP and HNT inside polymer phase was observed using SEM/EDS (field emission scanning electron microscopy/Energy dispersive X-ray spectroscopy). The properties of pretreated nanoclays are characterized using XRD (X-ray diffraction) and EDS. Chemical stability regarding radical attack against composite membranes is clarified using Ion meter through fluoride ion (F-) analysis. Proton conductivity of composite membranes is also measured under condition of different relative humidity and temperature. Following this, it is demonstrated by DMA (dynamic mechanical analysis) results that the particular elongated morphology of SEPs and HNTs participates to improving mechanical property of the composite membranes with decreased swelling ratio. MEAs (membrane electrode assembly) performance are evaluated to understand the advantage of the presence of nanoclays in the composite membranes regarding the relative humidity of the feeding gas, the operating temperature of the cell, and the hydrogen crossover. Detailed abstracts including main results were provided at the beginning of each chapter
Dijoux, Étienne. "Contrôle tolérant aux défauts appliqué aux systèmes pile à combustible à membrane échangeuse de protons (pemfc)." Thesis, La Réunion, 2019. http://www.theses.fr/2019LARE0008/document.
Fuel cells (FC) are powerful systems for electricity production. They have a good efficiency and do not generate greenhouse gases. This technology involves a lot of scientific fields, which leads to the appearance of strongly inter-dependent parameters. It makes the system particularly hard to control and increase the fault’s occurrence frequency. These two issues underline the necessity to maintain the expected system performance, even in faulty condition. It is a so-called “fault tolerant control” (FTC). The present paper aims to describe the state of the art of FTC applied to the proton exchange membrane fuel cell (PEMFC). The FTC approach is composed of two parts. First, a diagnostic part allows the identification and the isolation of a fault. It requires a good a priori knowledge of all the possible faults in the system. Then, a control part, where an optimal control strategy is needed to find the best operating point or to recover the fault
Pasquini, Luca. "Ion - conducting polymeric membranes for electrochemical energy devices." Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM4750.
The research aims to propose membranes for electrochemical devices alternative to the commercial ones able to reach the right compromise in term of good ionic conduction, stability and long life time for an high efficiency. We realized proton exchange, anion exchange and amphoteric membranes based on stable functionalized aromatic polymers (PEEK, PSU). We thus introduced sulfonic groups on a PEEK backbone to exchange protons or ammonium groups on PEEK and PSU to exchange anions. We also realized amphoteric membranes able to exchange at the same time both kinds of ions. The continuous optimization of synthesis parameters, the choice of different polymers and/or functionalization groups and the improvement of casting procedures and treatments of membranes, led to good results in terms of ionic conductivity, selectivity and stability.The study of the main parameters of the synthesized membranes demonstrates a thermal stability between 140 and 200°C depending on the selected membrane, a mechanical behavior characterized by a high elastic modulus and tensile strength and a relatively low ductility strongly influenced on the degree of hydration of the membrane as well as the eventual presence of cross-linking. Working on the degree of functionalization and the type of functionalizing groups, we obtained a tunable water uptake, an elevated ionic conductivity for different ions (up to ≃ 3 mS/cm for anionic conducting polymers) and a very low ion permeability (vanadium ions for RFB applications) down to ≃ 10-10 cm2/min, which is much below typical literature data for cation- and anion separation membranes and a challenge parameters for technological applications
Coudray, Mathias. "Procédé de recyclage des Assemblages Membrane Electrode (AME) de piles à combustible utilisant des liquides ioniques." Thesis, Lyon, 2019. https://n2t.net/ark:/47881/m6h70f5d.
Recovery of the protons-exchange membrane fuel cell (PEMFC) membrane electrode assemblies (MEAs) is an important issue for the growing of the fuel cells market. These MEAs contain platinum (Pt), which as a precious metal mainly influences the total cost of fuel cells. The recycling of Pt is still based to a great extent on hydro or pyrometallurgical techniques which produce toxic and pollutant gas emissions. Some studies aimed to set up processes to recycle platinum in a more sustainable way than traditional metal lixiviation using strong acids. The study here is part of this research field and is about a new way to separate the different components of the PEMFC electrode using ionic liquids for the recycling of these valuable materials. These liquids possess excellent thermal and chemical stability and their non-volatility can be useful to set up a safer way to recover platinum. A selection of ionic liquids was studied and some of them, including the P66614Cl (trihexyltetradecylphosphonium chloride), could be use to recover Pt nanoparticles detached from their carbon support and stabilized in the ionic liquid. A study on the interactions of ionic liquids and the components of the MEA allowed the extraction mecanisms to be better understood. Thus the ionics liquids interact strongly with Nafion in the catalyst layer which allows Pt nanoparticles to be recovered. These strong interactions set the stage for the simultaneous recycling of Nafion and Pt from MEAs
Passot, Sylvain. "Etude expérimentale et par modélisation de l'impact d'impuretés de l'hydrogène sur le fonctionnement des piles à combustible à membrane échangeuse de protons (PEMFC)." Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00813426.
Linares, Lamus Rafael Antonio. "Alimentation d’une bobine supraconductrice par une pile à combustible à hydrogène et conception d'un aimant vectoriel de 3 T." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0249/document.
The fuel cell (FC) converts the chemical energy of the reactants into direct electrical energy, heat and water. The FC is generally used around an operating point (or area) corresponding to a maximum of electric power. The direct current produced by the redox reaction is proportional to the active surface of the single cell and its voltage, which is approximately 0.6 V at the nominal operating point, can be increase by connecting several cells in series (constituting a stack). Due to its low DC voltage amplitude, its use in electrical systems requires the use of power converters. In this work, we have been interested taking benefit of such DC low voltage power source and more precisely the use of the FC as a current source controllable by the one of the reactant flow rates. The expertise of GREEN laboratory in the field of superconductors has naturally led us to an innovative application, namely to substitute the power supplies dedicated to the superconducting devices by a FC. A first promising test conducted on a 4 mH superconducting coil highlighted the full potential of such an application and encouraged us to extend the study to highly inductive superconducting coils where the energies involved are more important. This requires to carefully design the test bench with a protection system for the FC as well as operating conditions. To this end, a FC model supplying a superconducting coil has been developed and tested experimentally. At the same time, we have focused on the supply part of the superconducting coil by designing an innovative superconducting device, commonly called a three-axis vector magnet. This system can be used as a load for a fuel cell, but also, and above all, as a tool for the characterization of superconducting samples. This vector magnet allows to orient a magnetic field of several tesla in the three space directions, with a uniformity of more than 95 % in a 100 mm sphere of diameter. This design allowed us to realize the windings supporting structure and to choose a superconducting wire. The complete system has to cost less than 50 k€, including the cryostat, we have finally choose a superconducting wire with low critical temperature, cooled by liquid helium
Turtayeva, Zarina. "Genesis of AEMFC (anion exchange membrane fuel cell) at the lab scale : from PEMFC’s inks composition toward fuel cell bench tests in alkaline media." Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0285.
Anion exchange membrane fuel cells (AEMFCs) have recently attracted significant attention as low-cost alternative fuel cells to traditional proton exchange membrane fuel cells as a result of the possible use of platinum-group metal-free electrocatalysts. Although AEMFC is a mimic of PEMFC but working in an alkaline medium, water management issues are more severe in AEMFC because ORR in alkaline media requires water, while at the same time water is produced at the anode side. To better understand water management in this type of fuel cell, it is necessary first to develop and gain experience with this kind of fuel cell on the laboratory scale. Since no ready-to-use materials are available at the beginning of the project, the necessity of fabricating homemade MEAs from commercially available materials becomes a reality that we must face. As MEA fabrication is a new topic to LEMTA's researchers, this is why this thesis was divided into two parts: one part dedicated to the formulation, preparation, and optimization of MEAs for PEMFC through physico-chemical and electrochemical characterizations; another part dedicated to the development of AEMFC. The results indicated that ink deposition, composition, and preparation systematically change the electrode structure and thus affect fuel cells performance. Furthermore, the study provides information on the AEMFC procedures and methods. Here, we would like to share our know-how with newcomers in the field of preparation of MEA in ion exchange membrane fuel cells
Fofana, Daouda. "Modélisation et conception d'électrode cathodique multicouche à faible quantité de platine et haute performance pour les piles à combustible à membrane échangeuse de proton (PEMFC)." Thèse, Université du Québec à Trois-Rivières, 2013. http://depot-e.uqtr.ca/6975/1/030596129.pdf.
Baneton, Joffrey. "Couches catalytiques et membrane échangeuse de protons pour piles à combustible :Synthèse par plasma atmosphérique et caractérisation." Doctoral thesis, Universite Libre de Bruxelles, 2019. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/292147.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished
Dumercy, Laurent. "Contribution à la caractérisation thermique et fluidique d'une pile à combustible à membrane échangeuse de protons (PEMFC)." Besançon, 2004. http://www.theses.fr/2004BESA2004.
The aim of this thesis is the thermal and fluidic model of a proton exchange membrane fuel cell. The management of the internal temperature of the fuel cell affect performance, in one hand directly on the electrochemical reaction, in the other hand by determination of their internal caracteristics (hydratation of the membrane, diffusion resistance in the porous area). The modelisation is made between two axis. At first, the thermal behavior is taken into account in the global form. The fuel cell is studed as a whole with a thermal resistance network et heat sources (heat supply by electrochemical reaction, exchanges with fluids). Dirichlet boundary conditions have been used to force surface temperatures. The meshing of the network is shrink for modelizing the central cell. Specific boundary conditions are applied at this cell for quantify intterference of neighboring cells. The studied cell can be used, in this case, on many situations : adiabatic, in serial or with a external flux. In addition, anode and cathode channel have been studied with a specific model, based on the compting by finites differences of a differential equations system. Taking into account the most important physical and thermophysical quantities (pressions, flow rates, water and heat exchange coefficients), it couple internal quantities off the channel et thermal state of the overall system. The studies of the pahse change of water in the channel, his transfert beetwen the anode and the cathode and his influence on the thermal balance are studed
Touhami, Salah. "Apparition, détection et propagation des défauts à l'anode des piles à combustible à membrane échangeuse de protons." Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0151.
Defects known to shorten the lifetime of polymer electrolyte membrane fuel cells (PEMFC) can appear on different membrane electrode assembly (MEA) components and under different forms due to manufacturing processes or operational aging of the fuel cell. This work concerns the occurrence, detection, and propagation of defects in PEMFC MEA, and more specifically at the anode. To this end, an accelerated stress test (AST) combining potential and humidity cycles -induced by load variations-, and open-circuit hold is applied to standard MEA, and to MEA with initial defects. Those customized MEA were intentionally prepared with a lack of active layer at the anode, the defect being located either near the hydrogen inlet or near the hydrogen outlet. Periodic electrochemical characterizations were carried out using a segmented instrumented linear cell, allowing to monitor the cell performance through the currents, electrode potentials, and local impedance, as well as the evolution of the electrochemical active surface (ECSA) at the anode and cathode during the ageing test, with a spatial resolution along the channels. An electrochemical impedance spectroscopy study was conducted jointly, using equivalent electrical circuits, and focusing on the detection of the anodic contribution to the global impedance of the cell. Results showed an accelerated degradation of the MEA and the first evidence of defect propagation, in terms of loss of ECSA at the anode. This propagation occurred in the direction of the hydrogen flow. The ECSA at the cathode also appeared to be impacted, although apparently homogeneously. Significant membrane thinning was also observed in the defective segments, with probable propagation to adjacent segments, but over a longer time period
Rouhet, Marlene. "Etude de l'influence des protons sur la réduction de l'oxygène dans des couches catalytiques ordonnées en vue d'une application en pile à combustible." Thesis, Strasbourg, 2014. http://www.theses.fr/2014STRAF031/document.
Ordered catalytic layers based on vertically aligned carbon nanofilaments with Pt nanoparticles demonstrate high efficiency for oxygen transport and Pt utilization in the catalytic layer. Electrochemical studies combined with mathematical modeling confirm the influence of the proton transport on surface red-ox processes, the kinetics and the mechanism of the O2 reduction (ORR), and on the H2O2 escape. We show that (i) protons are involved in the rate-determining step of the O2 reduction, (ii) for pH ≥ 3, a plateau corresponding to the diffusion-limited current of protons is observed and, (iii) for pH ≥ 3, the mechanism of the ORR involves not only the hydronium ions but also water molecules. The integration of these catalytic layers in high temperature PEMFCs was then studied. The performance is slightly lower than that for conventional layers. An optimization work is required to improve the performance
Nandjou, Fredy. "Etude locale de la thermique dans les piles à combustibles pour application automobile. Corrélation à la durée de vie." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAI079/document.
One of the main challenges for Proton Exchange Membrane Fuel Cells development is the performance loss, which largely limits the durability. The study of the degradation phenomena of the different MEA components is a challenge addressed by many researchers, but a study at a stack scale is needed in order to better understand the ageing mechanisms. Indeed, in an industrial fuel cell the operating conditions are not homogeneous as for laboratory fuel cells, especially as regards thermal aspects. The heterogeneities are particularly emphasized for automotive fuel cells, because of the compactness constraint of the cooling circuit. Moreover, the requirements of cold start should be considered, as well as the inertial effects of the stacks and the increased heterogeneities during the driving cycles.In this work, the effects of the temperature heterogeneities and hot spots on the automotive fuel cell performances and degradations are investigated. The study is conducted in different conditions: nominal conditions, load/thermal cycling and New European Driving Cycles (NEDC).The work is composed of an experimental study, which consists of ageing tests on fuel cells and on-line diagnosis at both global and local scales. At the end of the tests, post-mortem analyses of the aged components are conducted. In parallel, a physic-based model is developed in order to predict the local temperature and humidity in the different components of the cell. Then, the impact of the reactive gases and cooling flow fields design on the thermal and water management of the cell is investigated. Finally, the experimental and modeling results are coupled in order to investigate the correlation between heat management, water management and degradations
Linares, Lamus Rafael Antonio. "Alimentation d’une bobine supraconductrice par une pile à combustible à hydrogène et conception d'un aimant vectoriel de 3 T." Electronic Thesis or Diss., Université de Lorraine, 2017. http://www.theses.fr/2017LORR0249.
The fuel cell (FC) converts the chemical energy of the reactants into direct electrical energy, heat and water. The FC is generally used around an operating point (or area) corresponding to a maximum of electric power. The direct current produced by the redox reaction is proportional to the active surface of the single cell and its voltage, which is approximately 0.6 V at the nominal operating point, can be increase by connecting several cells in series (constituting a stack). Due to its low DC voltage amplitude, its use in electrical systems requires the use of power converters. In this work, we have been interested taking benefit of such DC low voltage power source and more precisely the use of the FC as a current source controllable by the one of the reactant flow rates. The expertise of GREEN laboratory in the field of superconductors has naturally led us to an innovative application, namely to substitute the power supplies dedicated to the superconducting devices by a FC. A first promising test conducted on a 4 mH superconducting coil highlighted the full potential of such an application and encouraged us to extend the study to highly inductive superconducting coils where the energies involved are more important. This requires to carefully design the test bench with a protection system for the FC as well as operating conditions. To this end, a FC model supplying a superconducting coil has been developed and tested experimentally. At the same time, we have focused on the supply part of the superconducting coil by designing an innovative superconducting device, commonly called a three-axis vector magnet. This system can be used as a load for a fuel cell, but also, and above all, as a tool for the characterization of superconducting samples. This vector magnet allows to orient a magnetic field of several tesla in the three space directions, with a uniformity of more than 95 % in a 100 mm sphere of diameter. This design allowed us to realize the windings supporting structure and to choose a superconducting wire. The complete system has to cost less than 50 k€, including the cryostat, we have finally choose a superconducting wire with low critical temperature, cooled by liquid helium
Merle, Agnès. "Etude de catalyseurs à base de platine pour électrodes de piles à combustible à membrane échangeuse de protons." Lyon 1, 1996. http://www.theses.fr/1996LYO10125.
Tan, Chiuan Chorng. "A new concept of regenerative proton exchange membrane fuel cell (R-‐PEMFC)." Thesis, La Réunion, 2015. http://www.theses.fr/2015LARE0012.
The past works found in the literature have focused on either PEM fuel cell or electrolyzer-PEM. Some of the papers even studied the unitised reversible regenerative fuel cell (URFC) and the solar power hydrogen system by integrating both fuel cell and electrolyzer. Unlike the URFC, our design has an individual compartment for each PEMFC and E-PEM systems and named Quasi-URFC. With this new concept, the main objective is to reduce the cost of regenerative fuel cell (RFC) by minimizing the ratio of the catalyst’s geometric surface area of the membrane electrode assembly (MEA) of both cell modes. Apart from that, we also aim to build a compact, light and portable RFC.This research work is divided into three parts: the modeling, assembly of the prototype and the experimentation work. As for the modeling part, a 2D multi-physics model has been developed in order to analyze the performance of a three chamber-regenerative fuel cell, which consists of both fuel cell and electrolyzer systems. This numerical model is based on solving conservation equations of mass, momentum, species and electric current by using a finite-element approach on 2D grids. Simulations allow the calculation of velocity, gas concentration, current density and potential's distributions in fuel cell mode and electrolysis mode, thus help us to predict the behavior of Quasi-RFC. Besides that, the assembly of the first prototype of the new concept of regenerative fuel cell has been completed and tested during the three years of PhD studies. The experimental results of the Three-Chamber RFC are promising in both fuel cell and electrolyzer modes and validate the simulation results that previously obtained by modeling
Parra, Restrepo Julian. "Caractérisation des hétérogénéités de fonctionnement et de dégradation au sein d’un électrolyseur à membrane échangeuse de protons (PEM)." Electronic Thesis or Diss., Université de Lorraine, 2020. http://www.theses.fr/2020LORR0044.
Proton Exchange Membrane (PEM) electrolysis is among the best solutions to store energy from intermittent power sources such as solar and wind. The green hydrogen produced by this technology can meet the needs of industries that already consume hydrogen or can be used for new applications such as fuel cell cars. To continue the deployment of PEM electrolyzers, it is necessary to increase their lifetime and the active surface area of cells. By doing this, operating heterogeneities related to the distribution of gas/water, current and temperature may appear. This work aims to characterize the aging mechanisms and the heterogeneities that have a negative impact on the performance of the electrolyzer. A segmented cell for measuring local current densities and local potentials was developed. Different titanium porous transport layers (PTLs) were characterized and their influence on the transport of electrical charges and gas/water has been analyzed, which allowed identifying problems related to the variation of PTL microstructure along the electrolyzer. Also, a model describing the contact resistance between the catalyst layer and the PTL was proposed. The membrane temperature between the inlet and the outlet of the cell was estimated with an innovative method based on the electrochemical impedance spectroscopy. This method allowed characterizing the temperature differences with the water circulating in the channels as a function of current density. An accelerated stress protocol was developed and the influence of intermittent operation was studied. A critical potential threshold that accelerates aging was identified and performance recoveries linked to periodic drop of the cell potential were observed
Zhang, Dacheng. "Contribution to prognostics of proton exchange membrane fuel cells : approaches based on degradation information at multiple levels." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAT003/document.
In the context of the energy transition, fuel cell becomes one of the promising alternative energy sources. Recently the spotlight is on fuel cell systems research, and more particularly on Proton Exchange Membrane Fuel Cell (PEMFCs) which is one of the best candidates for both stationary and transportation applications. Even if this technology is close to being competitive, it is not yet ready to be considered for a large scale industrial deployment because of its limited durability and reliability. Prognostics and Health Management (PHM) is a recent approach to manage and possibly extend life duration of technological systems. Prognostic techniques can provide an estimation of fuel cell State Of Health (SOH) and a prediction for their Remaining Useful Life (RUL) to help the manufacturers improving fuel cell performance and managing its lifespan.The objective of this work is to develop prognostic methodologies for the RUL prognosis adapted to the complexity of PEMFCs. Indeed, the PEMFC is a multi-scale and multi-physics system, and various challenges are faced:1. The definition of SOH to build a degradation indicator.2. The coexistence of both reversible and irreversible degradation phenomena.3. Taking into account different deterioration causes and effects of operating conditions.In the first part of our work, we conduct a state of the art analysis on PHM for PEMFCs, with the aim of proposing a SOH definition and building a degradation indicator for PEMFC prognosis purposes. And since PEMFC measurements are scarce, the state of the art on Lithium batteries, other electrochemical cells, is also explored.In the second part, we develop a particle filtering based prognostic algorithm for PEMFC, based on output power measurements. The first results show that the prognosis algorithm is disturbed by the existing reversible degradation. However, the irreversible degradation can be estimated thanks to characterization tests, such as Electrochemical Impedance Spectroscopy (EIS), which is applied from time to time. We propose thus an adapted & extended prognostic algorithm to take into account both health indicators: the output power degradation and the SOH degradation estimated from EIS characterization. The performance of the proposed algorithm is evaluated by different prognostic performance metrics, and the results show the interest of this approach.In the third part, the problem is addressed from a more theoretical point of view. Indeed, a system's degradation behavior is often correlated with internal and external covariates which are usually difficult to access owing to expensive measurement cost. Therefore, we first developed a prognostic approach with online inspections on the degradation covariate at a different level, and then we propose an approach for RUL prognosis based on an ensemble of models using different sources at different levels. The RUL predictions of both models are dynamically aggregated on the basis of prognostic performance evaluated on a set of historical data. Consequently, the prediction accuracy is improved by overcoming both models' drawbacks and leveraging their strengths. In the last part, we extend the problem to multi-level prognostics and explore new possibilities, which open new aspects for future research on PEMFC lifetime prognosis and management
Karst, Nicolas. "Gestion de l'eau dans les micropiles à combustible." Phd thesis, Grenoble INPG, 2009. http://www.theses.fr/2009INPG0030.
The fuel cell, whose energy efficiency is potentially higher than that of the best Li-ion batteries currently proposed on the market, shows the possibility for considerable autonomies for wandering apparatuses. One of the main objectives to be reached for their marketing is the water management. This work aims at understanding and resolving this issue. We carried out studies on the influences of various environmental parameters (temperature, relative humidity,. . . ) as well structural factors (thickness of the cathodic collector, addition of a diffusion layer at cathode, packaging,. . . ) on water management. We propose solutions allowing management of both drying and flooding of micro fuel cells. One of the characteristics of the micro fuel cell studied here is that it is an air-breathing device using directly oxygen from air as combustive. It comes out from this study that these micro fuel cells are extremely sensitive to environmental conditions. In order to obtain optimal performances on a broad range of temperature and relative humidity, a completely passive water management will be insufficient. Thanks to the various results obtained during this work, a first prototype made up of nine micro fuel cells with an active water management is presented
Mrad, Christine. "Caractérisation ex-situ par RMN et IRM des transferts d'eau à l'interface membrane/électrode dans les piles à combustible PEMFC." Electronic Thesis or Diss., Université de Lorraine, 2023. http://www.theses.fr/2023LORR0358.
In the context of sustainable energy transition, Proton Exchange Membrane Fuel Cells (PEMFC) are considered promising alternatives to conventional engines. They offer efficient conversion of hydrogen into electricity without emitting pollutants. However, for the widespread deployment of these systems, it is essential to reduce their cost and improve their durability. This is the focus of the European project « ALPE: Advanced Low-Platinum hierarchical Electrocatalysts for low-T fuel cells », in which this thesis is situated. The project aims to reduce the cost of PEMFCs by decreasing the amount of platinum (Pt), catalyst used in their electrodes, targeting a reduction of 1.5 to 2 times compared to the state of the art in 2019. The operation of PEMFCs relies essentially on the electrochemical reactions occurring on the Pt catalytic sites, and proton transport is closely linked to the hydration state of the electrolyte membrane (water serving as a vector for protons). Therefore, the objective of this thesis is to study the impact of reducing the amount of Pt on the water transport phenomena across the membrane-electrode/air interfaces. In order to achieve this goal, experimental devices and methodologies for analyzing the membrane/electrode interface through spectroscopy and magnetic resonance imaging (NMR/MRI) have been developed. Initially, the study focuses on the examination of a single Nafion® membrane (N1110). An in-situ analysis that allows visualization of the impact of the membrane's hygrothermal history on the properties of water is presented. Furthermore, experiments under different relative humidity conditions on each side of the membrane demonstrate the capability of our approach to quantify interfacial resistances of water transfer while decoupling them from diffusive effects within the membrane. Additionally, a 1D steady-state model of the diffusion of water across the thickness of the membrane allows to determine the evolution of the mutual water diffusion coefficient. To complement our analysis, a partial acquisition measurement sequence has been designed to minimize the acquisition time of water profiles within the membrane, paving the way for a transient study. Finally, a comparison of interfacial resistances between a single membrane and a membrane with electrode(s) provides insights into the impact of adding an electrode deposit and varying the platinum loading on water transport phenomena. The results highlight that in transient conditions, there are no significant differences between a single Nafion® membrane and a membrane/electrode assembly (with one or two electrodes). However, it appears that the presence of the electrode and the amount of platinum seem to influence the evolution of interfacial resistances depending on the relative humidity (RH) of the air supplied to the sample
Bouatia, Eloumami Souhail. "Développement de matériaux électriquement conducteurs pour les plaques bipolaires de piles à combustibles à membrane échangeuse de protons, PEMFC." Thesis, Université Laval, 2008. http://www.theses.ulaval.ca/2008/25545/25545.pdf.
Sailler, Sébastien. "Générateurs électrochimiques et stockages ilôtés (G. E. S. I. )." Grenoble INPG, 2008. http://www.theses.fr/2008INPG0178.
The aim of this study was to design and study a hybrid system consisting in a fuel cell (proton exchange membrane fuel cell), a supercapacitor, and power electronic D-DC converters. The first part of this work deals with design specifications and on the conversion structure. Then, we interest on possible models of the fuel cell and the super capacitor. This was carry out in order to obtain a model of the complete system which is enough simple to use in power electronic simulation. Then, we have simulated the entire system in order to study system stability and performances. We try to validate hybrid system perfomance in regards with design specification. Finally we realize the hybrid system demonstrator and study his performances
Le, Ninivin Céline. "Elaboration et validation de dérivés polyparaphénylène substitués sulfonés comme électrolyte solide pour piles à combustible à membrane échangeuse de protons." Poitiers, 2003. http://www.theses.fr/2003POIT2318.
The synthesis and the valuation of sulfonated derivated polyparaphenylene (PPP) as solid electrolytes for proton exchange membrane fuel cells consist of the stake of this work. The approaches adopted concern the methods of introduction of the acid group and their influence on the properties of the ionic materials. The synthesis and characterization of three different side chains substitued PPP were realized. The study of the post sulfonation of two polymers and the grafting of another one with different fonctionnalized phenols allowed the preparation of ionic copolymers with variables properties. This grafting method is particularly original in the case of sulfonated perfluorinated phenol with thermally stable aromatic polymers. Many physico-chemical characterization (conductivity, permeability, mechanical properties and morphology) show interesting differences between post sulfonated materials and grafted materials. Some relationship between structures and properties are observed and discussed. The role of many fuel cell tests parameters like temperature, membrane thickness, copolymer acidity, was studied. The results point out that polyparaphenylene, and especially the perfluorinated grafted copolymer, are promising materials for PEMFC application. More than, the results of fuel cell tests are in good agreement with the physico-chemical characterization
Straubhaar, Benjamin. "Pore network modelling of condensation in gas diffusion layers of proton exchange membrane fuel cell." Phd thesis, Toulouse, INPT, 2015. http://oatao.univ-toulouse.fr/19261/1/Straubhaar_B.pdf.
Danerol, Anne-Sophie. "Etude des mécanismes de vieillissement des assemblages membrane/électrodes utilisés comme coeurs de pile à combustible." Chambéry, 2008. http://www.theses.fr/2008CHAMS050.
One of the key components in the Proton Exchange Membrane Fuel Cell (PEMFC) is the membrane / electrode assembly (MEA). Such MEA is a multilayered structure based on perfluorosulfonic acid polymer membrane as Nafion®, coated on both sides by active layers, and covered by gas diffusion layers. The electrodes are constituted of porous carbon supported nanosized Pt catalyst, with an oligomer-binding agent similar in nature to the polymer electrolyte. A large series of scouting characterization techniques was used in order to point out pertinent 'ageing markers' related to stationary life test conditions. First, macroscopic investigations were performed with the help of the common Electrochemical Impedance Spectroscopy technique that appeared inadequate to characterize in situ ageing or to detect pinholes. Thus, a new global non-destructive diagnosis tool, called 'the relaxation technique', based on the super capacitor behaviour of MEAs, was developed. In a second step, we focused on the active layers degradation mechanisms. In addition to standard techniques (SEM, TEM, XRD), new methods were employed. Thereby, thermogravimetric analyses revealed changes in thermal stability behaviour of the electrodes upon ageing, attributed to chemical modifications of the oligomer-binding agent. In addition, peel tests pointed out an improvement of the electrode-membrane adhesion with increasing ageing time, suggesting a diffusion / crystallization of the binding agent species mainly near the interface. Eventually, chemical, thermal and microstructural characterizations of the electrolyte revealed changes in the chemical structure upon ageing. A drastic decrease in the chain mobility was then assigned to ionic crosslinking related to some cationic contamination of the membrane during fuel cell operation. In conclusion, although the active layers are first prone to degradation, it seems that the lifetime of the system is mainly related to the degradation of the membrane
M'Batna, Jean Paul. "Contribution à la modélisation tridimensionnelle du comportement termo fluidique d'une cellule de pile à combustible à membrane échangeuse de protons." Phd thesis, Université de Technologie de Belfort-Montbeliard, 2009. http://tel.archives-ouvertes.fr/tel-00601707.
M'batna, Jean-Paul. "Contribution à la modélisation tridimensionnelle du comportement termo fluidique d'une cellule de pile à combustible à membrane échangeuse de protons." Belfort-Montbéliard, 2009. http://tel.archives-ouvertes.fr/docs/00/60/17/07/PDF/M_BATNA_THESE_UTBM.pdf.
The fuel cell systems are integrated into a set of auxiliary constraints that are operating them. To consider a good performance, it is necessary to better control these aids in eliminating the maximum such constraints. Modeling is increasingly considered to provide an answer. Among these different types of models, there is that which is to treat the problem of water management, the main cause of flooding of sites reactive electrodes batteries. Such an approach can not be done without difficulty because it requires the coupling of several equations. By using a CFD code FLUENT, we deal in a real configuration of a type of model that can enable us to provide an answer to the problem of water status of the cell. This consists of determining some parameters of transfer at he heart of the battery as the cell temperature, relative humidity, partial pressures and the molar flow components
Ratieuville, Vincent. "Elaboration et caractérisation de nouvelles membranes thermostables pour application piles à combustible." Rouen, 2014. http://www.theses.fr/2014ROUES056.
The aim of the present work was to develop thermally stable proton-conducting membranes for cell application. Indeed, performances of the Nafion® membrane, reference for PEMFC (Proton Exchange Membrane Fuel Cell), are limited due to a conductivity loss above 90°C caused by dehydration effect. To solve this problem and to overcome the hydration dependence of membranes, two approaches have been investigated. The first one was to elaborate membranes based on polyimide (Matrimid®) and protic ionic liquid (IL) as either supporrted ionic liquid membrane (SILM) or as a composite membrane by simple blending. SILM presents the best properties (mechanical strength, ion conductivity, etc. ) but an IL leakage was observed with temperature increasing. The second approach involved the development of ionomer membranes based on synthetised conductive polymers, namely polyazole (POD). In order to improve the mechanical stability and the ionic conductivity of POD, different membranes were elaborated by its association with Matrimid® and IL (BIM-DBP) or with a sulfonic co-monomer (SBA). Encouraging results were obtained during conductivity measurements. In this work , a correlation between the structure of the studied membranes and their ionic conductivity, permeation, thermal, mechanical and chemical properties, as well as pressure stability was established