Tesi sul tema "Pile à combustible à membrane échangeuse d'anions"
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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
Akrour, Laurent. "Membrane échangeuse anionique et application en pile à combustible". Paris, CNAM, 2005. http://www.theses.fr/2005CNAM0493.
The objective of this study is to produce an anion exchange membrane being able to be used in an alkaline fuel cell with alkaline polymeric solid electrolyte. The quaternaryammonium groups formed by the DABCO and quinuclidine shows a good resistance to thermal degradation. The membranes synthetised from the polyépichlorhydrine, the copolymer polyépichlorhydrine-allyl glycidyl ether and the two preceding amines are crosslinked by thermal and photochemical way. The photocrosslinked membranes have an ionic exchange capacity of 1,3 mèq/g and a conductivity of about 8. 10[puissance]-2 S/cm at 25°C in KOH 2,5M. The interfaces electrode-membranes studied under oxygen and hydrogen, with an half-cell assembly, were optimized and make it possible to produce an alkaaline fuel cell with membranes developing a maximum power of about 100 mW/cm2 under H2/O2 at 25°C and 12mW/cm2 with a methanol-KOH 4M mixture at 25°C
Latour, Antoine. "Etude et développement d'une pile à combustible liquide à membrane échange d'anions". Grenoble INPG, 2006. http://www.theses.fr/2006INPG0114.
A new concept of fuel cell has been studied. The originality of this system consists on the use of an anions ex change membrane and on the use on a liquid fuel different from methanol. This study aims at proving the feasability of such a fuel cell by associating fundamental studies and more technological works. Various parameters of ethylene glycol/air fuel cells and sodium borohydride / air fuel cells have been studied. The oxygen reduction reaction was carried out in alkaline medium on several catalysts. Platinum alloys are not tolerant to the presence of ethyene glycol while carbon-supported silver nanoparticles dispersed on carbon and the macrocyle CoTMPP are completly insensitive to ethylene glycol. Despite their lower activity, these catalysts are more adapted than platinum to anions-ex change membrane fuel cells
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
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
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
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
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.
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
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
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.
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
Rambaud, Frédéric. "Elaboration de matériaux hybrides par procédé sol-gel pour application pile à combustible PEMFC". Paris 6, 2011. http://www.theses.fr/2011PA066046.
Hybrid membranes composed of a non-conductive protonic organic polymer with an inorganic conductive particles were produced for a PEMFC application with the objective of increasing the operating temperature. In order to lengthen the life expectancy of the electrodes and to improve its effectiveness, we need to increase the operating temperature. The original concept of this study employed the use of an anisotrope functionalized inorganic mesoporous componant dispersed into an organic phase. Silica is a material known for its hygroscopic characteristics. Additionally, silica has an easily modifiable surface, which brings interesting properties to electrolyte application. The first step of this study consisted of morphological control of the hybrid charge with a shape factor higher than 8 and with a large specific surface structure. The obtained nanofibers induced the protonic conduction into the polymer by forming preferential conduction paths of protons through the membrane. The movement of these cations was performed by incorporating sulfonic groups onto the porous surface of the fibers. The protonic motion was dependent on the number of active sites. A post-hybridation was necessary to increase the performance of the hybrid nanofibers. Two manners of post-incorporation and processes were studied and improved, which gave a protonic conduction equivalent to Nafion®
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
Ferrandez, Anne-Claire. "Synthèse et caractérisation des nouvelles architectures catalytiques pour une application en pile à combustible du type PEMFC". Poitiers, 2011. http://nuxeo.edel.univ-poitiers.fr/nuxeo/site/esupversions/1cb2c4a4-6d5f-47d5-b0a0-5d40f245abd4.
This thesis is within the scope of new catalytic layers development for proton exchange membrane fuel cell (PEMFC) based on the transposition of the phenomenology of the three-phase boundary at the molecular scale. The fieldwork concerns the working out of hybrid organic/inorganic catalyst by grafting proton conducting polymers (PSS). Both methods have been developed to introduce the polymer on the platinum nanoparticles. The first method consists of using the "grafting from" technique and controlled radical polymerization (Atom Transfer Radical Polymerization). The second grafting method used is the "grafting onto" technique. It consists first in synthesizing the polymer and second in grafting by reaction of the functions of the latter with platinum nanoparticles. Modifications of synthesis parameters allowed constituting a collection of objects showing a wide range of grafting density. Electrochemical characterizations have brought numerous information on the structure, activity and selectivity of hybrid catalytic complex
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
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
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
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
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.
Nguyen, Dinh An. "Modélisation dynamique du "coeur" de pile à combustible de type PEM". Electronic Thesis or Diss., Vandoeuvre-les-Nancy, INPL, 2010. http://www.theses.fr/2010INPL035N.
Being a new source of supplying electrical and thermal decentralized energy, the fuel cells offer better energy efficiency and reduced emissions for sustainable development. This thesis deals with the physicochemical phenomena that occur in a single cell of fuel cell proton exchange membrane. A 2Ddynamic model was developed and solved numerically by the finite element method using thesoftware COMSOL Multiphysics. The simulated static and dynamic polarization curves are confronted with measurements made on a 100cm² single cell test bench that belongs to GREEN Laboratory. Aparametric study, such as the influence of operating conditions, different stress current has been simulated and tested. The single cell dynamic behavior to a current step and more particularly to adirect connection to capacitor has underlined the importance of the electrical double layer phenomenon, located at the membrane / electrode interfaces, to describe precisely fast transients.Finally, spectroscopy impedance as a tool widely used to characterize the cell has been implemented in simulation allowing the analysis of the effects of this measurement method on the local parameters
Nguyen, Dinh An. "Modélisation dynamique du "coeur" de pile à combustible de type PEM". Thesis, Vandoeuvre-les-Nancy, INPL, 2010. http://www.theses.fr/2010INPL035N/document.
Being a new source of supplying electrical and thermal decentralized energy, the fuel cells offer better energy efficiency and reduced emissions for sustainable development. This thesis deals with the physicochemical phenomena that occur in a single cell of fuel cell proton exchange membrane. A 2Ddynamic model was developed and solved numerically by the finite element method using thesoftware COMSOL Multiphysics. The simulated static and dynamic polarization curves are confronted with measurements made on a 100cm² single cell test bench that belongs to GREEN Laboratory. Aparametric study, such as the influence of operating conditions, different stress current has been simulated and tested. The single cell dynamic behavior to a current step and more particularly to adirect connection to capacitor has underlined the importance of the electrical double layer phenomenon, located at the membrane / electrode interfaces, to describe precisely fast transients.Finally, spectroscopy impedance as a tool widely used to characterize the cell has been implemented in simulation allowing the analysis of the effects of this measurement method on the local parameters
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.
Sadli, Idris. "Modélisation par impédance d'une pile à combustible PEM pour utilisation en électronique de puissance". Thesis, Vandoeuvre-les-Nancy, INPL, 2006. http://www.theses.fr/2006INPL091N/document.
This thesis deals with dynamic modelling of a proton exchange membrane fuel cell (PEMFC) with a view to integrate it into power electronics environment. Firstly a static model based on an expression that links current and voltage is presented. The dynamic model is then obtained. It is shown that the electrochemical diffusion-convection impedance (Zd) is similar to a RC transmission line. A discretization on a short number of elements is carried out. In order to obtain a simple model, two different RC branches for Zd impedance, a double layer capacitor, a transfer resistance, and a membrane resistance are considered. This modelling is validated on two 500 W and 5 kW PEMFC, for frequencies varying from 5 mHz to 2 kHz. The model is validated for both fuel cells during current step responses and operation with a boost converter. In this case it is shown how the high frequency switching of the converter can be used to obtain a diagnostic on the humidification state of the membrane
Benallouch, Mohamed. "Observation des systèmes non-linéaire à entrées inconnues : application à la pile à combustible de type PEM". Strasbourg, 2009. http://www.theses.fr/2009STRA6091.
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
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
Cellier, Julien. "Etude et caractérisations de membranes nanocomposites hybrides pour pile à combustible du type PEMFC". Thesis, Tours, 2017. http://www.theses.fr/2017TOUR4001/document.
The proton conductive membrane is an essential part of the operation of PEMFC. This document presents the development of a non-perfluorinated membrane based on a hybrid nanocomposite technology likely to be produced at low cost. This membrane is composed of a poly(VDF-co-HFP) matrix in which are dispersed poly(styrene sulphonic acid) (PSSA) functionalized silica nanoparticles. This work focuses on the study of the implementation of the membrane to obtain a homogeneous and dense membrane with good physicochemical and electrochemical characteristics. Fuel cell performances after running at 60 °C are extremely satisfactory with a gain, compared to Nafion NRE211, of 40% for the power density at 0.7 V. However, the durability studies showed an elution phenomenon of the functionalized silica particles which results in a high voltage decline. Different membrane modification strategies have been proposed to improve the stability of the membrane. The most interesting involve modifying the morphology of the matrix (more rigid grades of PVDF or poly(VDF-co-HFP) crosslinking by radiation) to better confine the particles or grafting functionalized silica to the matrix. This last strategy leads to a threefold decrease of the swelling and 2.5 factor of the decay rate at 80 °C
Sadli, Idris. "Modélisation par impédance d'une pile à combustible PEM pour utilisation en électronique de puissance". Electronic Thesis or Diss., Vandoeuvre-les-Nancy, INPL, 2006. http://www.theses.fr/2006INPL091N.
This thesis deals with dynamic modelling of a proton exchange membrane fuel cell (PEMFC) with a view to integrate it into power electronics environment. Firstly a static model based on an expression that links current and voltage is presented. The dynamic model is then obtained. It is shown that the electrochemical diffusion-convection impedance (Zd) is similar to a RC transmission line. A discretization on a short number of elements is carried out. In order to obtain a simple model, two different RC branches for Zd impedance, a double layer capacitor, a transfer resistance, and a membrane resistance are considered. This modelling is validated on two 500 W and 5 kW PEMFC, for frequencies varying from 5 mHz to 2 kHz. The model is validated for both fuel cells during current step responses and operation with a boost converter. In this case it is shown how the high frequency switching of the converter can be used to obtain a diagnostic on the humidification state of the membrane
Seck, Serigne. "Elaboration de matériaux hybrides organiques / inorganiques par extrusion réactive : Application en pile à combustible". Thesis, Lyon, INSA, 2013. http://www.theses.fr/2013ISAL0027.
Fuel cells technologies are electrochemical energy conversion devices and have a real potential to revolutionize the way to produce energy, offering cleaner, more-efficient alternatives to combustion of gasoline and other fossil fuels. In that way, the Proton Exchange Membrane Fuel Cells (PEMFC) are probably the most studied. Those fuel cells are mainly based on perfluorosulfonic acid membranes, such as Nafion®. However, Nafion® membranes, present some limitations such as dehydration at high temperatures or at low relative humidity rate leading to a decrease of proton conductivity and thus poor PEMFC performance. Consequently, PEMFC require significant improvements prior to be largely used in the automobile field. Research efforts have been oriented on the development of new materials for the PEMFC membrane as it is the main limitative component for high temperature fuel cell. In the present contribution, we wish to report the validation of a new concept of hybrid materials for the realization of proton exchange membranes. The originality of this hybrid concept is based on the contribution of both phases’ specific properties. We investigated the preparation of hybrid materials based on an inert polymer matrix (low cost) providing the mechanical stability embedding inorganic phase providing the necessary properties of proton-conduction and water retention. Hybrid nanocomposite membranes were synthesized using evaporation and recasting technique from solution containing dispersion of inorganic particles in the adequate polymer. Scanning electron microscopy (SEM) images for membrane morphology and proton conductivity results using impedance measurements from hybrid membranes will be presented. The performance of the membrane-electrode assembly (MEA) using the hybrid membrane was also evaluated by a fuel cell test. Finally, we wish to present a promising way of research based on Sol-Gel approach to generate a proton-conducting inorganic phase into the polymer matrix
Salah, Abdelkrim. "Simulation et contrôle de l'aspect thermique d'une pile à combustible PEMFC". Besançon, 2008. http://www.theses.fr/2008BESA2062.
This thesis deals with contribution to thermal problems of PEM Fuel Cell. In fact, since the chemical conversion of energy stored within the fuel cell is accompanied by the production of an important thermal energy (50 %), it is most important to understand the thermal behavior of fuel cell. Majority of models involves complex systems of heat differential equations. In addition, PEMFC presents a heterogeneous system and thermal coupling of conduction-convection involves complex differential equations, and their solution can not be done within a reasonable amount of time by sequential program. In the first part of this work, seeking reliable and simple method for study of thermal behavior phenomena, we have developed the nodal approach that result from a formal analogy between analogical circuits and their counterpart’s phenomena. In this approach, we can represent the two phenomena of conduction-convection without any coupling of with another approach of representation. It will be shown in this thesis that this model presents high scalability and parallel processing characteristics that make it suitable for simulation on parallel machines or a network of workstations. In the second part of this work, we have interested to the control of the temperature of fuel cell. The model inspired by the nodal approach that we have developed is in the bilinear form. We propose a result on feedback stabilization of thermal behavior of PEM Fuel Cell
Lepesant, Mathieu. "Catalyseurs multimétalliques nano-organisés pour pile à combustible PEM". Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENI052/document.
The decrease in cost of catalysts is one of the conditions necessary to make economically viable PEMFC technology to the general public. These catalysts, usually composed of platinum nanoparticles, are limited by cost, performance and durability. Nanostructuring is one of the possible solutions for these catalysts because it greatly increases the surface area, reducing the platinum loading and increase performance for the reaction of oxygen reduction, the most limiting in PEMFC technology.The works presented in this thesis were performed on two types of nanostructured particles (core-shell particles, hollow particles) based on platinum or platinum alloy. These particles have been studied, characterize in electrochemistry to 3 electrodes (rotating ring-disk electrode and half-cell assembly) and then integrated in fuel cell systems. We observed performance improvements offered by this type of electro-catalytic particles towards the reduction reaction of oxygen and then we started studying and optimize their integration into fuel cells and actual conditions of operation
Klein, Mathieu. "Développement de méthodes RMN/IRM dédiées à l'étude des phénomènes de transport dans les piles à combustible à membrane échangeuse de protons". Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0274/document.
This work focuses on the development of MRI/NMR methods dedicated to the characterization of water transport properties in a polymer membrane used in PEMFC. Radiofrequency coils are used to (1) study water self-diffusion coefficient in uniaxially stretched membranes and (2) spatially and temporally resolved measurements of the water distribution through the membrane. These measurements provide information about the influence of the polymer structure on water transport properties and also on real-time water distribution through the membrane in various humidity conditions. The water diffusion anisotropy is intimately linked to the structural order of the polymer. The steady-state and transient profiles of water content through the membrane indicate that mass transfer is limited by the interfacial resistances and mainly by the polymer relaxation during sorption
Lamibrac, Adrien. "Étude des dégradations dans les piles à combustible PEMFC pendant les phases de démarrage/arrêt". Thesis, Université de Lorraine, 2013. http://www.theses.fr/2013LORR0117/document.
This works contributes to the identification of the various degradation mechanisms in Polymer Electrolyte Membrane Fuel Cell during start-up and shut-down operations. Single start-ups and shut-downs are first analysed using a cell with segmented cathode current collectors. Thus, internal currents which occur during these operations can be measured. Carbon dioxide measured in the cathode exhaust gas reveals that they result partially from carbon oxidation. Another contribution is the reversible or non reversible redox reactions involving platinum. The heterogeneity of the non reversible platinum oxidation between the inlet and outlet of the cathode is evidenced by the in-situ monitoring of the Electrochemical Surface Area during long-term start-up and shut-down aging protocols. Post-mortem analysis reveals another level of heterogeneity, which concerns also carbon oxidation, between land and channel. From these experiments, it appears also that degradations are more important when gases are injected with a low velocity in the anode compartment and when air is used instead of nitrogen to flush the anode compartment during shut-down. The influence of the MEA characteristics on the extent of the degradation observed during these aging protocols is also analyzed. High platinum loading in the anode and high surface carbon electrodes accelerate the drop of the electrical performances, while increasing the cathode platinum loading limits their decay. Finally, numerical simulations of start-ups complete the experimental results. Reversible platinum oxidation was found to be one of the main contribution to the internal currents
Dos, Santos Leslie. "Mécanisme de conduction protonique au sein de membranes hybrides pour piles à combustible". Electronic Thesis or Diss., Paris 6, 2014. http://www.theses.fr/2014PA066612.
Proton exchange membrane fuel cell (PEMFC) has recently received increasing attention as a clean renewable power source due to its high operational efficiency and minimal environmental impact. The currently well-developed PEMFC technology is based on perfluorosulfonic polymers acid membranes as electrolyte. The reference membrane is Nafion due to their excellent chemical, mechanical, and thermal stability. However, Nafion presents several drawbacks as high cost and relative low operational temperatures. An alternative to replace commercials membranes is the development of organic-inorganic hybrid membranes for fuel cell applications. The advantage of these membranes is the decoupling of the proton transport from the mechanical properties. This hybrid membrane combines the intrinsic physical and chemical properties of both the inorganic and organic components allowing desirable properties. The swelling of the membrane can be adjusted via the composition of the membrane. A new hybrid membrane composed of silica and polymer PVDF-HFP is synthesised by combining sol gel chemistry and electrospinning. The association between the sol gel process and electrospinning permits the creation of an inorganic network within the polymer membrane, and morphological control to tune the proton pathway. This process recreated the nanoseparation observed in hydrated Nafion while being in dependent of water quantity. This organisation is strongly correlated with high conductivity of nafion. These news membranes are made of polymer fibbers surrounded by a functionalized (-SO3H) inorganic network. This microstructure conduces to membranes with conductivity values comparable to Nafion. To optimize the sol-gel chemistry and the electrospinning parameters, there is a need to understand proton mechanisms in these multiscale materials. Several characterisation techniques are used to explain the microstructure and to understand the link with conductivity values
Asset, Tristan. "Particules creuses peu expensives, durables et actives pour la réduction de l'oxygène dans le cadre d'une application en pile à combustible à membrane échangeuse de protons". Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAI037/document.
This thesis investigates the mechanisms driving the formation, the en-hanced activity for the oxygen reduction reaction (ORR) and the dura-bility of porous hollow PtM/C nanoparticles (NPs) for proton exchange membrane fuel cell (PEMFC) applications. The formation and growth of the NPs, synthesized by a ‘one-pot’ process, were discussed in the light of microscopic, in operando X-ray and electronic measurements, unveiling the different intermediate steps of the synthesis. The synthe-sis process was extended to different non-noble metals (M = Ni, Co, Cu, Zn and Fe) and to different carbon supports. The enhanced activity for the ORR resulted from (i) the contraction of the lattice parameter by the non-noble metal (the final NPs contains ca. 15 – 20 at. % of M), (ii) the open porosity and (iii) the density of structural defects at the surface of the NPs, rationalized by COads stripping measurments and Rietveld analysis. The non-noble metal was found to segregate faster than the structural defects during the accelerated stress tests
Cuynet, Stéphane. "Etude des conditions d’élaboration d’électrodes de pile à combustible PEMFC par procédés plasma". Thesis, Orléans, 2014. http://www.theses.fr/2014ORLE2027/document.
From a collaboration between the CNRS laboratory of the CEA and GREMI Ripault, the objective of this thesis is to conduct a complete study on the conditions for producing electrodes of PEM fuel cell by plasma processes in order to improve the electro-catalytic activity of the catalyst (Pt). The platinum atoms on its support appears to be a one of the most important factor determining the performance delivered by the PEMFCs. From this observation, several lines of research have been proposed and each of them has yielded new results. The High Power Impulse Magnetron Sputtering (HiPIMS) process is studied in case of depositions of noble materials (Pt, Au, Pd) and alloy (Pt5Pd95 and Pt50Pd50) and revealed an ionized metal vapor consequent upon deposition (10 % to 90 % depending of the element). The results obtained on the HIPIMS process have allowed a change in the distribution of a small fixed amount of Pt (20 μg.cm−2) deposited on the depth of the gas diffusion layer (GDL), incidentally improving the performance of PEMFCs (+80% at 0.65 V, the voltage at rated power). This result is complemented by those obtained on the development of allied catalysts, especially with the arrangement of the catalytic material on the aggregates structure (+93 % at 0.65 V for Pt5Pd95 in successive deposits). In order to modify the Pt atoms distribution on the membrane support, another study has been realized. The surface of the proton exchange membrane has been structurated before the Pt deposition. Such structuration have shown an increase of the overall performance of PEMFCs in the case of CCB (Catalyst Coated Backing) and CCM (Catalyst Coated Membrane) architecture with an improvement factor of 1.3 up to 12, respectively
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.
Chupin, Sylvain. "Comportement local et performances électriques d'une pile à combustible à membrane : vers un outil de diagnostic". Thesis, Université du Québec à Trois-Rivières, 2009. http://www.theses.fr/2009INPL098N/document.
The present work contributes to the understanding of water management and thermal management of a PEM fuel cell influences on the electrical performances. A bidimensional model representing mass and heat transfer in the cell thickness and along distribution channels is done. A specific part of the study concerns a microscopic representation of reactive agglomerates. This part presents the impact of the liquid water presence on local and global current densities. In te vein of integrating this model in a total fuel cell control system, simplifications have been done and coupled mass, heat and charge transfers are solved analytically. For any operating condition, the model gives a complete view of the hydric, thermal and electric inner situation of the cell. This diagnosis of the inner state of the cell leads to find the operating conditions giving to the optimal electric performances. Water, current and temperature distributions are presenting for different gas feeding strategies and different thermal management configurations. A specific part is dedicated to illustrate how this local diagnosis of the cell state can be used to estimate its global electric performances
Noiying, Panee. "Modélisation locale d'une cellule de pile à combustible pour l'étude de systèmes électriques". Electronic Thesis or Diss., Université de Lorraine, 2013. http://www.theses.fr/2013LORR0043.
A heart of a fuel cell is a multi-physics system that couples mass and charge transport phenomena (in electrodes and electrolyte), and electrochemical kinetics at reactive sites ; to these phenomena, are added thermal transfer, and gas distribution problems. Many mathematical models have already been developed in order to describe locally these phenomena, through partial differential equations involving space and time. Theses models are often accurate, but they are hardly used in a system approach, since one aims to study a complex system in which the fuel cell is only one element among others. Many semi-empirical dynamics models have also been developed, with an electrochemical cell represented by an equivalent electrical circuit, the parameters of which are often determined experimentally, by spectroscopy measurements in particular. The main drawback of this approach is that it results in small signal models, which are theoretically only available around an operating point. The works presented in this thesis deals with the development, the experimental validation and the use of a 1D local PEM fuel cell model, of circuit type for a direct implementation in simulation software commonly used in electrical engineering (Saber® in our case). The elements of the model are determined by using electrical analogy of physical phenomena that occur in the fuel cell. The model is dynamic, and takes into account electric double layer, and influence of operating conditions (notably gas supply effects, such as over-feeding or transient gas starvation) on fuel cell performances. The first chapter presents literature review on existing fuel cell models, and enable to situate our work in this context. We give in chapter 2 local equations on which our model is based: gas transport in diffusion layers, water transport in the membrane, charge transport in electrodes and membrane, electrochemical kinetics at the membrane-electrode interfaces, electric double layer, boundary conditions. Then we detail the analogy representation that allows to compute transport equations by means of electrical engineering simulation software, as well as to complete electrical model. A comparison with a similar model implemented in a software using the finite element method is proposed, then an experimental validation in steady and transient state is carried out. The last chapter deals with the exploitation of the model for parametric study purposes (operating conditions, physical parameters), and for system simulation purposes (specific operations of a single cell, multi-cells in series, association with a power electronic converter)
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
Dalet, Corinne. "Gestion de l'eau dans un système pile à combustible pour traction automobile : transferts couplés dans un humidificateur membranaire". Thesis, Nancy 1, 2009. http://www.theses.fr/2009NAN10136/document.
This report presents a synthesis of works carried out in order to solve the water management problematic in a PEM fuel cell system. An analysis of the different components of the system air line, and more specifically the membrane humidifier, is realized in order to determine the architecture allowing the optimal moisture content of air upstream the fuel cell whatever the operating conditions. This study involves the description and the understanding of coupled heat and mass transfers within the humidifier, through numerical and experimental approaches. The numerical section contains a model of coupled transfer through a Nafion membrane. Associated with a thermodynamic analysis of the humidifier, it allows to define two parameters characterizing respectively the mass exchanges and the heat transfers, according to the inlet conditions of the fluids or as well as to the exchanger geometry. These parameters turn out to be useful design tools. The experimental section allows to estimate the interactions between a fuel cell, the humidifier and the other air line components. Besides the analysis of components response to a current intensity variation, the investigations allowed to demonstrate that the operating conditions of the system is compatible with the chosen humidification technology
Dos, Santos Leslie. "Mécanisme de conduction protonique au sein de membranes hybrides pour piles à combustible". Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066612/document.
Proton exchange membrane fuel cell (PEMFC) has recently received increasing attention as a clean renewable power source due to its high operational efficiency and minimal environmental impact. The currently well-developed PEMFC technology is based on perfluorosulfonic polymers acid membranes as electrolyte. The reference membrane is Nafion due to their excellent chemical, mechanical, and thermal stability. However, Nafion presents several drawbacks as high cost and relative low operational temperatures. An alternative to replace commercials membranes is the development of organic-inorganic hybrid membranes for fuel cell applications. The advantage of these membranes is the decoupling of the proton transport from the mechanical properties. This hybrid membrane combines the intrinsic physical and chemical properties of both the inorganic and organic components allowing desirable properties. The swelling of the membrane can be adjusted via the composition of the membrane. A new hybrid membrane composed of silica and polymer PVDF-HFP is synthesised by combining sol gel chemistry and electrospinning. The association between the sol gel process and electrospinning permits the creation of an inorganic network within the polymer membrane, and morphological control to tune the proton pathway. This process recreated the nanoseparation observed in hydrated Nafion while being in dependent of water quantity. This organisation is strongly correlated with high conductivity of nafion. These news membranes are made of polymer fibbers surrounded by a functionalized (-SO3H) inorganic network. This microstructure conduces to membranes with conductivity values comparable to Nafion. To optimize the sol-gel chemistry and the electrospinning parameters, there is a need to understand proton mechanisms in these multiscale materials. Several characterisation techniques are used to explain the microstructure and to understand the link with conductivity values
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
De, Moor Gilles. "Approche multi-échelle des mécanismes de vieillissement des coeurs de pile à combustible". Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAI049/document.
In spite of strong improvements in fuel cell design this last ten years, Proton Exchange Membrane Fuel Cell are still suffering of premature end of life. Failure of the heart of fuel cell, composed of membrane and catalysts, is commonly responsible for fuel cell shutdown. This work brings an original contribution in understanding membrane degradation mechanisms. Different ageing tests were analyzed, in laboratory as well as in real life operating conditions (up to 13000 hours of solicitations). Within a multi-scale approach, from macroscopic to microscopic, and with a systematic usage (hundreds of samples fully characterized), some degradation mechanisms were established. Firstly, macroscopic tools were specifically developed to rapidly track state of health of all the cells from each stack. With the help of these tools, we were able to identify defects inter and intra-cell. It was also possible to discriminate between gas crossover or electronic short-circuit defects, both responsible for current leaks. This systematic approach on each samples put forward some specific areas within the membrane where degradation was promoted. Secondly, physico-chemical characterizations were performed on membrane targeted areas. It was shown that membrane degradation is strongly localized in some specific channels of the bipolar plates and favored by specific operating conditions in the gaz inlets areas
Niane, Moustapha. "Contribution au diagnostic et à la commande de la pile à combustible de type PEM". Electronic Thesis or Diss., Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0426.
The fuel cell is a device that transforms the chemical energy in electricity. This device requires some auxiliaries for its operation. In order to ensure the performances in terms of security, reliability and life cycle of the fuel cell, adequate diagnostic and control systems are indispensables. This thesis is a contribution to the problem of faults diagnosis and control of PEM Fuel Cell. The first part of this work is dedicated to the development of diagnostic methods applied to the fuel cell. To do this, two approaches are proposed. The first one concerns the synthesis of a H-/H∞ filter allowing the sensors and actuators faults detection while ensuring a level of robustness towards disturbances. Taking into account the fuel cell system characteristics, the conditions for existence and stability of the filter are given in the form of Linear Matrix Inequalities (LMI). The second approach deals with the problem of parametric faults detection. For this purpose, an adaptive observer has been proposed, which makes it possible to estimate the value of the parameter likely to exhibit a failure. This method gives the possibility of simultaneously estimating the parametric faults and the unmeasured states of the system. The second part of the thesis is dedicated to the control of the fuel cell system. The purpose is to synthesize a feedback control law that allows to answer the load request while respecting a nominal operating constraint of the fuel cell. Such a functioning allows to have a better efficiency while preserving the state of health of the fuel cell. The control law is obtained by using the original nonlinear model and without any kind of linearization
Ozouf, Guillaume. "Electrodes à base d’aérogels de SnO2, résistantes à la corrosion pour la réduction de l’oxygène dans les piles à combustible à membrane échangeuse de protons (PEMFC)". Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLEM060/document.
In order to tackle the problem of low durability, tin dioxide aerogels were studied to replace carbon black as a catalyst support in proton exchange membrane fuel cells (PEMFCs). SnO2 is a well-known n-type semi-conductor whose electronic conductivity can be improved by doping with hypervalent cations such as Nb5+, Ta5+ or Sb5+. In addition, as a catalyst support, this material has to develop a high specific surface area with adequate mesoporous morphology to allow both good dispersion and activity of the catalyst (Pt). To this end, our objective was to develop doped SnO2 aerogels. In this study, SnO2 based-aerogels were successfully synthesized following an acid-catalyzed sol–gel route starting with metal alkoxides as precursors. Our materials have shown a very interesting airy morphology with among other a reasonable specific surface area (80–90 m2/g). Moreover, all Sb-doped aerogels exhibited significant improvement in electronic conductivity and reach a value of around 0.12 S/cm. Platinum nanoparticles were then deposed on the Sb doped SnO2 aerogel surface using three different methods. The method based on chemical reduction using a polyol route provided the best result in term of mass catalytic activity measured by RDE (Is = 32 mA/mgPt). This value is even higher than that of the reference electrocatalyst TEC10E40E (Is = 27 mA/mgPt). Sb doped SnO2 aerogel based MEAs have exhibited a very good durability at high potentials
Hugot, Nathalie. "Élaboration et caractérisation de nouveaux matériaux d'électrodes pour pile à combustible à membrane échangeuse de protons : catalyseurs à base de tungstène supportés sur un dérivé du graphite expansé". Thesis, Université de Lorraine, 2013. http://www.theses.fr/2013LORR0061/document.
This work is implicated in the development of carbon materials and of materials for energy applications. In the first part, we aim to totally or partially replace the platinum catalyst of the Proton Exchange Membrane Fuel Cell by less expensive and more abundant materials. In the second part, we optimize the catalytic sites accessibility for the reactants. WCl6 was impregnated on the Expanded Graphite derivated substrate by gaseous transport under chlorine pressure before being reduced and/or carburized in order to obtain tungsten derivatives (tungsten, tungsten carbides). The nature and size of the nanoparticles depend on the reducing or carburizing gas composition (H2 or H2/CH4 mixture) and the reaction temperature. Reduction is not complete until 500°C when using H2. W2C and WC mixtures are formed when using H2/CH4 mixtures (90/10, 85/15 or 80/20). The temperature increasing favours the sintering effect but not the complete carburization. All these obtained catalysts show low electrocatalytic performances when tested on a half-cell system. Platinum-tungsten hemicarbides catalysts were obtained by a successive deposition of PtCl4 and WCl6 while the reduction-carburization step was realized at 900°C under H2/CH4 mixture (85/15). These materials show higher electrocatalytic performances than a commercial platinum catalyst for an equivalent platinum ratio. The final part of this work concerns the carbon support functionnalization with sulfonate groups. Polystyrene sufonate grafting seems efficient for it helps to reduce the Nafion quantities used in the electrodes and to increase the electrocatalytic performances