Dissertations / Theses on the topic 'Pile à combustible à membrane polymere'
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Monin, Guillaume. "Stabilisation chimique des électrolytes polymères pour pile à combustible." Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00728176.
Full textCoursange, Jean-François. "Modélisation de pile à combustible à membrane de polymère en 3D /." Trois-Rivières : Université du Québec à Trois-Rivières, 2003. http://www.uqtr.ca/biblio/notice/resume/17681831R.html.
Full textCe mémoire contient aussi un article de périodique, publié dans la revue Fuel Cells, 2003.- "Performance comparison between planar and tubular-shaped PEM fuel cells by three-dimensional numerical simulation" / J.-F. Coursange, A. Hourri, J. Hamelin. Bibliogr.: f. 51-52.
Coursange, Jean-François. "Modélisation de pile à combustible à membrane de polymère en 3D." Thèse, Université du Québec à Trois-Rivières, 2003. http://depot-e.uqtr.ca/4024/1/000103641.pdf.
Full textGerbaux, Luc. "Modélisation d'une pile à combustible de type hydrogène/air et validation expérimentale." Grenoble INPG, 1996. http://www.theses.fr/1996INPG0163.
Full textGibon, Cécile. "Membrane composite polymère fluoré / polyélectrolyte pour pile à combustible : relations structure - propriétés." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2006. http://tel.archives-ouvertes.fr/tel-00143683.
Full textLes solubilités en solution du polyélectrolyte puis du mélange sont étudiées. Les morphologies des membranes et la cristallinité du Kynar sont ensuite caractérisées. Un comportement de type LCST est mis en évidence. L'utilisation de contre-ions tétrabutylammonium (TBA) permet d'obtenir des mélanges miscibles. Le TBA est ensuite échangé, la forme acide du PAMPS étant nécessaire au fonctionnement en pile. La perméabilité à l'eau et la conductivité ionique sont enfin caractérisées. Une nanostructuration de type bicontinu est particulièrement efficace pour l'application envisagée. Pour stabiliser cette morphologie, un copolymère polyélectrolyte réticulable est synthétisé.
Chabert, France. "Élaboration par extrusion de membranes polymères pour piles à combustible." Grenoble INPG, 2004. http://www.theses.fr/2004INPG0132.
Full textThe aim of these studies was to process membranes by extrusion to be used in fuel cells. The functional polymers used are generally processed by polluting techniques like casting-evaporation, which are not easily transposable on industrial scale. Extrusion is a widely used shaping operation in the polymer processing industry. However, extrusion had not been used until now for arylsulfonic ionic polymers. In order to avoid any risk of degradation of the polymer during extrusion, it was necessary to define the best processing conditions. On one hand, the physicochemical characterization of the polysulfones (commercial) and sulfonated polysulfones (or synthesized by the project partners), were performed by determining their molecular weights and their thermal transitions. On the order hand, their flow behaviour was characterized over a wide range of temperatures and shearing rates using rheometric techniques. The combination of these two characterizations allowed to define the appropriate extrusion conditions. For the extruded films, the conductivities, measured by impedance spectroscopy were found to be similar with those of the membranes processed by casting-evaporation and close to those of Nafion® membranes. In addition, the incorporation of a proton-conducting filler and reinforcing fibres was also considered and the extrusion of these composite materials was validated. This work could be extended to other proton-conducting polymers, like polyetherethercetones and polyetherimides, whose membranes produced by casting-evaporation have already shown their performances in the fuel cells
Thiry, Xavier. "Synthèse et caractérisation de matériaux polymères conducteurs protoniques pour membranes de pile à combustible." Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENI041/document.
Full textThis thesis deals with the conception of proton conducting materials used as PEMFCmembrane. The proposed approach is quite new in this application field and is based on thedevelopment of semi-interpenetrating networks (semi-IPN). A linear conducting polymer(sulfonated PEEK) was combined with a crosslinked fluorinated network, a poly(aryl etherperfluorocyclobutane) (PFCB). These macromolecules are obtained by thermalcyclodimerization of bis and tris trifluorovinylether monomers (TFVE). Different series ofsemi-IPN were prepared by changing the PFCB nature, the crosslinking degree, the synthesisprocess and the proportion of the network added to the sPEEK. The overall results show aspecific semi-IPN composition for which the conductivity, the swelling and mechanicalstrength properties are optimal. A membrane with a proton conductivity of 155 mS.cm-1 and alimited water swelling (50 % lower than for a sPEEK membrane which exhibits a protonconductivity of 127 mS.cm-1) is obtained by adding 10 wt-% of fluorinated network. Inaddition, the incorporation of sulfonated TFVE monomers into the network PFCB has beenconsidered. A significant effort in organic chemistry enabled the synthesis of bis-TFVEmolecules containing protected sulfonated functions in a sulfonate ester form. Linearconducting PFCB polymers with a predeterminated IEC were obtained by directcopolycondensation of these monomers
Schieda, Mauricio. "Elaboration par CVD plasma et caractérisation de matériaux pour pile à combustible à membrane alcaline." Montpellier 2, 2007. http://www.theses.fr/2007MON20202.
Full textGuimet, Adrien. "Nouvelles Membranes Conductrices Protoniques à base de Polymères Perfluorosulfonés Acides pour Application Pile à Combustible." Thesis, Cergy-Pontoise, 2015. http://www.theses.fr/2015CERG0767/document.
Full textThis work focuses on the synthesis and characterization of new proton conducting membranes based on Aquivion®, a perfluorosulfonic acid ionomer (PFSA), for Proton Exchange Membrane Fuel Cell (PEMFC) application. Two approaches have been used to strengthen thermomechanical properties of this PFSA for operation above 80 °C. The first approach is the blend of Aquivion® with a sulfonated poly (ether ether ketone) (S-PEEK), leading to Aquivion/S-PEEK materials. In the second approach, Aquivion® is combined with a neutral Fluorolink® MD 700 fluorinated polymer network through semi-interpenetrating polymer network architecture (semi-IPN). In comparison, S-PEEK has also been associated with the same neutral network. All of these materials have been synthesized over a wide range of compositions.Their ion exchange capacity, mechanical properties, sorption and transport of water, and proton conductivity as well as their mechanical, chemical and thermal stabilities have been extensively characterized. Morphology of these new materials has also been studied using different microscopy techniques. Finally, thanks to these ex-situ studies, fuel cell tests from 80 to 105 °C have been investigated on the most promising membranes, whose performances are similar or higher compared to single PFSA membranes
Zaton, Marta. "Study of the degradation of perfluorosulfonic acid fuel cell membranes and development of mitigation strategy." Thesis, Montpellier 2, 2014. http://www.theses.fr/2014MON20197.
Full textThis thesis describes the study the chemical degradation of perfluorosulfonic acid (PFSA) membranes used in proton exchange membrane fuel cells, in order to gain a better understanding of the mechanisms leading to failure, and to propose strategies to mitigate this degradation. Studies of membrane chemical decomposition were performed on pristine Nafion and on cerium and manganese ion exchanged membranes. The effectiveness of Mn and Ce species as free radical scavengers was studied by using accelerated stress tests: in situ in a single fuel cell under open circuit voltage (OCV), and ex situ using Fenton's reagent. Membrane chemical degradation was assessed by the fluoride emission rate (FER). Significant reduction in FER was observed with Mn and Ce ion modified Nafion. These observations were related to the fuel cell performances losses and migration or elution of metal ions, as evaluated by SEM/EDX and HPLC, and to changes in the oxidation state of the metal species, determined by XPS. The results have been used to provide further guidance on materials strategies to mitigate membrane chemical degradation. A composite nanofibre CeOx/PFSA mat was prepared by electrospinning of a mixed dispersion of Nafion® ionomer with CeOx nanoparticles synthesised by flash combustion. The electrospinning technique allows fabrication of a homogenous material with well controlled thickness and highly dispersed CeOx. This mat was assembled with PFSA membranes by hot-pressing. These nanofibre mats are the means of siting the CeOx radical scavenger specifically in close proximity to one or other catalyst layer, rather than distributed throughout the membrane. The new membranes were further investigated by OCV hold testing in a fuel cell. The results show that MEAs integrating a non-modified PFSA membrane, or a PFSA membrane modified by an interlayer of nanofibre PFSA (no CeOx) only, demonstrate a marked drop in OCV with time, and high FER. In contrast an MEA comprising a CeOx nanofibre interlayer gives very stable open circuit voltage and low fluoride emission. Finally it was observed that the nanofibre – ceria interlayer is more effective when incorporated at the anode side. Post mortem analysis of the MEAs and analysis of exhaust water were combined to draw a picture of the overall degradation processes occurring in cerium oxide protected and non-modified MEAs. X-ray photoelectron spectroscopy, Raman spectroscopy and scanning electron microscopy analyses of aged MEAs indicated a lower degree of degradation for CeOx protected membranes than for a non-modified PFSA membrane. These results are in agreement with OCV profile and fluoride emission rate. In conclusion this new approach to the strategy of incorporating of radical scavengers to mitigate membrane chemical degradation efficiently increases membrane durability, and allows location of the radical scavenger within the MEA at the sites potentially most exposed to radical attack
Cornet, Nathalie. "Relation entre la structure et les propriétés de membranes en polyimide sulfone pour pile à combustible H2/O2." Université Joseph Fourier (Grenoble), 1999. http://www.theses.fr/1999GRE10164.
Full textRamousse, Julien. "Transferts couplés masse-charge-chaleur dans une cellule de pile à combustible à membrane polymère." Vandoeuvre-les-Nancy, INPL, 2005. http://www.theses.fr/2005INPL098N.
Full textUnderstanding and modelling of coupled mass, charges and heat transfers phenomena are fundamental to analyse the electrical behaviour of the system. The aim of the present model is to describe electrical performances of a PEFMC according to the fluidic and thermal operating conditions. The water content of the membrane and the water distribution in the single cell are estimated according to the coupled simulations of mass transport in the thickness of the single cell and in the feeding channels of the bipolar plates. A microscopic model of a Gas Diffusion Electrode is built up to describe charges transfer phenomena occurring at the electrodes. Completed by a study of heat transfer in the Membrane Electrode Assembly, conditions and preferential sites of water vapour condensation can be highlighted. A set of measurements of the effective thermal conductivity of carbon felts used in fuel cells as porous backing layers have also been performed. Although the value of this parameter is essential for the study of heat transfer, it is still under investigation because of the strong thermal anisotropy of the medium
Ramousse, Julien Maillet Denis. "Transferts couplés masse-charge-chaleur dans une cellule de pile à combustible à membrane polymère." Vandoeuvre-les-Nancy : INPL, 2005. http://www.scd.inpl-nancy.fr/theses/2005_RAMOUSSE_J.pdf.
Full textPéron, Jennifer. "Nouvelles membranes de polybenzimidazoles sulfonés pour application en pile à combustible : étude des mécanismes de dégradation des assemblages membrane-électrodes." Montpellier 2, 2007. http://www.theses.fr/2007MON20108.
Full textHis work is related to the development of PEM fuel cells. The first part of the manuscript describes the preparation of new sulfonated polybenzimidazoles, allowing to obtain proton conducting membranes, using two different ways: direct sulfonation of the polymer backbone under mild conditions, introduction of a sulfonated monomer during polymer synthesis. Direct sulfonation lead to highly proton conducting polymers that can be used as polyelectrolyte in electrochemical devices like fuel cells. The second part describes the study that has been done to determine membrane-electrodes (MEA) degradation mechanisms during fuel cell operation. MEA characterisation during, and after, running at high potential allow us to evidence catalysts dissolution, and further migration, in the perfluorosulfonated ionomer. Pt(II) species present in the ionomer lead to radical formation and causes electrolyte degradation
Escribano, Sylvie. "Optimisation de nouvelles électrodes pour piles à combustible hydrogène/oxygène à membrane électrolyte polymère." Grenoble INPG, 1995. http://www.theses.fr/1995INPG0148.
Full textNiether, Christiane. "Étude de l’oxydation électrocatalytique de l’éthanol dans les conditions d’une pile à combustible à membrane électrolyte polymère haute température." Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS026/document.
Full textThe heterogeneous electrocatalytic ethanol oxidation reaction (EOR) in the gas phase has been studied in the temperature range of 120 °C to 180 °C under proton exchange membrane fuel cell (PEM-FC) conditions. Direct ethanol fuel cells (DEFC) offer the possibility to gain electrical energy from a renewable fuel with a pre-existing distribution infrastructure. However the high theoretical energy efficiency that is one of the major advantages of fuel cells cannot be achieved to date with ethanol. Reasons for this are the formation of incomplete oxidation products and inert adsorbates that hinder the electrocatalytic oxidation of ethanol. A better understanding of the reaction mechanism and the influence of reaction conditions is crucial for the optimization of DEFC technology. Several studies have been done on the EOR in aqueous solution, but none so far in the gas phase.For this purpose a test cell with a three electrode assembly has been built. It can operate at temperatures up to 180 °C and is connected to a mass spectrometer for online differential electrochemical mass spectrometry (DEMS) measurements to detect volatile oxidation products in the fuel cell exhaust. Thus the amount of the complete oxidation product carbon dioxide formed during electrooxidation of ethanol can be obtained and allows drawing conclusions on the efficiency of the reaction under varying conditions. In addition a qualitative detection of the side products of the EOR is possible. The effect of temperature on the EOR has been studied on Pt black catalyst in the temperature range of 120 °C to 160 °C. Another focus is the effect of the ethanol concentration on carbon supported Pt/C and PtRh/C catalysts at 150 °C and how the addition of Rh influences the performance and product selectivity of the EOR
Perrot, Carine. "Mécanismes de dégradation des membranes polyaromatiques sulfonées en pile à combustible." Phd thesis, Université Joseph Fourier (Grenoble), 2006. http://tel.archives-ouvertes.fr/tel-00145619.
Full textCette étude porte sur la compréhension des mécanismes mis en jeu lors du vieillissement de membranes alternatives, non fluorées, de type PEEKs et PIs, étape indispensable au développement de structures plus stables. Dans ce cas, le processus est avant tout chimique. Une démarche originale, qui consiste à étudier le mécanisme de dégradation sur des structures modèles, a été adoptée afin de contourner les difficultés analytiques propres aux polymères. Les vieillissements sont réalisés dans l'eau, éventuellement additionnée de H2O2 (identifié comme une des causes du vieillissement chimique des membranes en pile), à différentes températures. La démarche consiste à isoler par chromatographie les différents produits formés, à les identifier (RMN, IR, SM) et à les quantifier. Ceci nous a permis d'établir le mécanisme de vieillissement. Nous avons en particulier montré que le vieillissement d'une structure PEEKs résulte principalement d'une attaque par les bouts de chaîne qui se propage à l'ensemble. Ce mécanisme a été validé sur une membrane vieillie en ex-situ et testée en pile. Ces deux types de vieillissement conduisent à une diminution importante du degré de polymérisation (déterminé par CES) et à la formation des mêmes produits primaires de dégradation. En pile, une dégradation hétérogène est mise en évidence essentiellement côté cathode.
Les PIs sont connus pour leur forte sensibilité à l'hydrolyse. Toutefois, nous avons pu montrer que la dégradation est relativement limitée à 80°C en raison d'une recombinaison des espèces hydrolysées.
Thounthong, Phatiphat. "CONCEPTION D'UNE SOURCE HYBRIDE UTILISANTUNE PILE A COMBUSTIBLE ET DESSUPERCONDENSATEURS." Phd thesis, Institut National Polytechnique de Lorraine - INPL, 2005. http://tel.archives-ouvertes.fr/tel-00083105.
Full textsupercondensateurs, destiné à fonctionner dans un véhicule à pile à combustible sont
présentés dans cette thèse. Deux modes de commande sont détaillés. Leur but est de permettre
un fonctionnement en quasi-statique de la pile à combustible afin de limiter les contraintes
mécaniques sur la pile en accordant les débits de gaz à la demande en courant. Les
supercapacités interviennent lors du non-fonctionnement de la pile, lors de régimes
transitoires ou de régimes de récupération.
Le dispositif développé utilise deux modules de supercapacités SAFT. Il est connecté à un bus
continu 42 V par un convertisseur continu-continu deux quadrants, la pile à combustible étant
connectée au bus continu par un convertisseur élévateur. Le contrôle des courants est réalisé
de manière analogique. Le contrôle des tensions et les algorithmes d'estimation utilisent une
carte numérique dSPACE. Les résultats expérimentaux présentés, obtenus avec une pile de
500 W, ont souligné la lenteur naturelle des réponses de la pile à combustible et l'apport des
supercapacités pour des applications automobiles. Celles-ci améliorent grandement la
dynamique et le contrôle énergétique du système.
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.
Full textFuel 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
Agel, Eric. "Electrode à air électrolyte solide polymère alcalin pour piles à combustible et générateur métal-air." Paris 7, 2002. http://www.theses.fr/2002PA077002.
Full textGao, Hongrong. "Stabilisation des Membranes Perfluorosulfoniques par Réticulation et Développement de Membranes Composites Inorganique-organique. Application aux Piles à Combustible à Moyenne Température." Thesis, Montpellier 2, 2010. http://www.theses.fr/2010MON20236.
Full textThe objective of this research was to develop cross-linked and composite inorganic-organic membranes based on long and short side chain (LSC, SSC) perfluorosulfonic acid (PFSA) polymers with low equivalent weight/high ion exchange capacity for operation at medium temperature and low relative humidity in proton exchange membrane fuel cells. Covalently cross-linked LSC-PFSA membranes were prepared from sulfonyl fluoride form membranes by reaction with an ammonium base followed by thermal processing to give cross-linking through sulfonimide groups. Covalently cross-linked SSC-PFSA membranes were prepared by formation of perfluoro-cross-links under thermal treatment of solution cast polymers containing cross-linkable 2-bromo-1,1,2,2-tetrafluoroethoxy side chains. Evidence for cross-linking was provided by IR, Raman, NMR and XPS spectroscopies, SEM-EDX, tensile testing and TGA. Cross-linked LSC and SSC-PFSA membranes have increased dimensional stability and improved performance in a single hydrogen-oxygen cell fuel up to 110°C compared with the corresponding non-cross-linked membranes. Composite PFSA-zirconium phosphate membranes, based on LSC and SSC PFSA (or cross-linked PFSA) membranes were prepared using an ion exchange/precipitation procedure. The physical properties of LSC-PFSA-ZrP and SSC-PFSA-ZrP have been compared and the morphology of the composite membranes shown to differ in SSC and LSC membranes. Composite membranes enabled fuel cell operation at higher temperature/lower RH than non-composite PFSA. Preliminary results indicated that association of cross-linking and composite membrane formation is a clear future perspective of this work
Baradie, Bilal. "Membranes ionomères composites pour piles à combustibles H2/O2 : élaboration et caractérisation." Grenoble INPG, 1997. http://www.theses.fr/1997INPG0002.
Full textLegrand, Pauline. "Influence des conditions de fonctionnement de la pile à combustible sur les performances du dispositif et la durabilité de la membrane." Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00767130.
Full textChabé, Jérémy. "Étude des interactions moléculaires polymère-eau lors de l'hydratation de la membrane Nafion, électrolyte de référence de la pile à combustible." Grenoble 1, 2008. http://www.theses.fr/2008GRE10038.
Full textThe Nafion is a polymer. Thanks to its high conductivity (up to ] 0-'< S. Cm-') at high relative humidity (RH), it is a reference electrolyt for a fuel cell. However its conductivity falls during low hydration conditions. To solve this problem, we can add a hygroscopic compound, like ziconium phosphate (ZrP), into the membrane. The conductivity is linked to the structure of the membrane, the proton diffusion mechanisms and the interactions between water molecules and the polymer; we are interested by this last field of research. Infrared spectroscopy are used to establish the hydration mechanisms at a molecular scale for a Nafion and a Nafion-ZrP membrane. This technique can be coupled with a molecular dynamic study, which we have begun for the Nafion. The inftared spectra ofNafion and Nafion-ZrP have been measured on the whole range of RH. We found 5 hydration mechanisms for the Nafion membrane. The ionisation of sulfonic groups S03H is very fast at the beginning ofhydration. Then the protons H+ move away from the sulfonate groups S03- and the net ofhydrogen bonds around these ionic groups changes. For a RH of 40%, bulk water appears inside the membrane. We have thus a "photograph" of the inner membrane at each stage of RH. The adding of an inoganic compound ZrP has no influence on the hydration mechanisms. According to the comparison between our mechanisms and the curve of conductivity, all the sulfonic groups have to be dissociated to reach optimal diffusion ofthe Droton, probablv assured bv the Grotthuss mechanism
Fichou, Swiecicka Joanna. "Synthèse de polymères à chaînes latérales perfluoroalkyles sulfonées pour la conception de membranes conductrices protoniques." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEI116/document.
Full textAs part of this work, the objective was to develop aromatic polymers with proton conduction properties. To achieve this, the sulfonic acid motifs were introduced along the macromolecular chains. The methodology of synthesis of these polymers was to polymerise the precursor containing in their structure a perfluoroalkyl sulfone moieties. Four novel precursors have been initially synthesized. Different aromatic polymers were prepared from these precursors by varying the rate of perfluoroalkyl sulfonated sequences. These polymers were then used in the form of dense membranes obtained by a casting process of evaporation. From these membranes, swelling studies in water and ionic conductivity were carried out
Ressam, Ibitissam. "Élaboration et caractérisation de nouvelles membranes composites à conduction protonique pour les piles à combustible." Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066732.
Full textThe perfluoro-sulfonated ionomer membranes are employed as separators in many industrialapplications such as fuel cells, chloro-alkali industry, electrodialysis and gaining inclininginterest in aqueous rechargeable or redox-flow batteries where the knowledge of their ionictransport and transfer properties is fundamental.Particularly, Nafion is adopted as a referencemembrane for polymer electrolyte membrane (PEM) fuel cells due to its thermal stability andgood proton conductivity. However, Nafion membranes have several disadvantages such as a decrease in the proton conductivity at low relative humidity (<50%) and high temperatures(>80°C), and excessive dimensional changes due to the swelling/deswelling, leading tomechanical instabilities.To circumvent these problems, novel proton conducting membraneshave been developed, either by completely replacing or by using organic and/or inorganiccomponents to Nafion.3 In this regard, a large spectrum of membranes have been elaboratedconsidering many attributes such as high proton conductivity, physical separation between theanode and the cathode and fuel barrier characteristics, good chemical and physical stability andlow elaboration cost of the membrane. Two types of additives were examined to improve the performances, particularly : Membranes based on Nafion with Chitosan biopolymer. This naturel polymer is consideredas the second most abundant polysaccharide after cellulose.6 Chitosan improves the physical andchemical stability of the membrane in the presence of water, and it is considered as a less costlyadditive to Nafion7.The improvement of the proton conductivity with pristine chitosan isessentially challenging. Previous studies demonstrated that vehicularandGrotthuss mechanismjointly govern the proton transfer in chitosan membranes.In the vehicular mechanism, the protons diffuse together with solvent molecules in the form of hydronium ions byforming acomplex such as H5O2+ and H9O4+. In the Grotthuss mechanism, however, the protons jump fromone solvent molecule or functional group to the next by the continuous formation and breakingof hydrogen bonds. Membranes based on Nafion with Halloysite nanotubes (HNT). These clays confer to themembrane high proton conductivity by constructing large and continuous conductionpathways.These inorganic additives also improve the thermal and mechanical properties of PEM. Composite membranes of Nafion/Chitosan- SO3H and Nafion/HNT-SO3H are prepared. Theresulting composite membranes were studied by various conventional structural characterizationtechniques. H+ conductivity measurements were performed and the values obtained are higherthan those of pristine Nafion at various relative humidity (RH%) levels and temperatures (30°C-80°C). Our results highlight the beneficial character of functionalized chitosan biopolymer andHalloysite nanotube clays as additives to improve PEM performances
Bernard, D'arbigny Julien. "Synthèse, caractérisation et mise en forme d'électrodes nanocomposites platine / carbure de tungstène pour les piles à combustibles à membrane haute température." Thesis, Montpellier 2, 2012. http://www.theses.fr/2012MON20144/document.
Full textThe objective of this work was to develop alternative suitable materials to increase operating temperature of a Proton Exchange Membrane Fuel Cell. The increase of the operating temperature (150 - 250 °C) is attractive for cost reduction and reliability in terms of reaction kinetics, catalyst tolerance, heat rejection and water management. Our work was focused on tungsten carbide which has an high electrical conductivity and exhibits a significant catalytic activity for hydrogen oxidation and oxygen reduction in acidic environment. We have reported a novel approach to produce tungsten carbide microspheres (TCM) with an high surface area (68 m2.g-1 including only 4 % of residual carbon) and an unusual architecture. Platinum nanoparticles were prepared by polyol method and were then deposited on TCM. Physical, chemical as well as electrochemical characterisations of WC supported platinum nanoparticles Pt/WC are described and discussed in comparison with a platinum electrocatalyst on a commercial carbon support (Vulcan XC-72R). Membrane Electrode Assembly was then prepared by coating - decal process, and characterised by single cell test and compared to conventional Pt/C assembly. Phosphoric acid doped polybenzimidazole PBI(H3PO4) was used as electrolyte to replace Nafion membrane in order to carry out fuel cell testing at higher temperature
Savych, Maciejasz Juliia. "Synthèse et caractérisation de nanocomposites platine/nanofibres pour électrodes de pile à combustible à électrolyte polymère." Thesis, Montpellier 2, 2014. http://www.theses.fr/2014MON20152/document.
Full textThe objective of this thesis is to develop corrosion resistant catalyst support materials that can potentially replace carbon in Polymer electrolyte fuel cells. Therefore, Nb doped TiO2 and SnO2 nanofibres and nanotubes were prepared by electrospinning and characterised by X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, N2 adsorption/desorption analysis and electronic conductivity measurements. The obtained Nb doped TiO2 and SnO2 one dimensional structures demonstrated higher conductivity and surface area than non-doped oxides. Pt nanoparticles were prepared using a modified microwave-assisted polyol method and deposited on the electrospun supports. Electrochemical characterisation of the obtained electrocatalysts was performed ex situ using a rotating disc electrode, and compared with a commercial carbon support (Vulcan XC-72R). Pt supported on Nb doped SnO2 provided higher electrochemical stability in comparison to Pt on carbon. Thus, a cathode of Pt/Nb-SnO2 prepared by spray-coating was integrated into Membrane Electrode Assembly (MEA) and characterised in situ in single Polymer electrolyte fuel cell. The MEA exhibited higher durability though lower power density compared to MEA with Pt/C based cathode. Sb doped SnO2 nanotubes have higher conductivity than Nb doped material and when integrated into a cathode, provided enhanced power density in comparison to Nb-SnO2 based cathode
Mrozewski, Kamil Janusz. "Diagnosis of mechanical tightening of a single polymer electrolyte membrane fuel cell (LT-PEM and HT-PEM) in aeronautical applications." Thesis, Toulouse, INPT, 2019. http://www.theses.fr/2019INPT0034/document.
Full textThe aeronautical R&D activities are currently shaped by the issues associated with the pollutantrich nature of the industry and the natural evolution towards more effective and sustainable technologies. In this regard, the development of more electric aircraft would contribute to reducing fossil fuel consumption by incorporating alternative sources and converters of energy, such as FCs. However, a FC system would have to comply with particular reliability and safety constraints, especially as the aeronautical environment is not very indulgent: abundant pressure and temperature cycling as well as mechanical loads, varying both in frequency and amplitude, in all three dimensions. Vibrations and shocks can in particular lead to a sudden or gradual loosening of the FC, thus degrading its performance, and possibly provoking a gas leak. It therefore seems important to be able to monitor the tightening state of a FC over time, ideally in a non-intrusive manner. Results reported in the literature indicate that the quality of the mechanical tightening of a FC assembly might be assessed through its ohmic resistance (Rohm), more precisely through its electronic part (Re-, formed by the bulk resistances of FC layers and the interfacial contact resistances). In nominal operating conditions, the second and more dominant part of Rohm – the protonic resistance (RH+, formed by the membrane and ionomer resistances) – does not depend on clamping pressure. This amalgamation of resistances of different natures prevents an easy extraction of Re- without the use of invasive sensors and thus an estimation of the quality of the mechanical tightening of a FC assembly. This thesis proposes an in situ preventive diagnosis method that is capable of detecting the degradation of clamping conditions of a FC through the modelling of its ohmic resistance. A theoretical study is performed and demonstrates that the RH+ and Re- resistances can be separated from the total Rohm, based on their temperature dependence. The proposed method is verified with experimental data generated during the characterization of low and high temperature Polymer Electrolyte Membrane (PEM) single cells. Although some differences between the values identified by the algorithm and those reported in the literature are observed, they correctly depict the behavior of the mechanical tightening of the tested FCs. Overall, the results are encouraging in the aim of monitoring the quality of mechanical tightening of a FC through the evolution of RH+ and Re-
Kamara, Konakpo Parfait. "Stratégies d’utilisation du bio hydrogène pour la technologie PEMFC : utilisation directe." Electronic Thesis or Diss., Université Grenoble Alpes, 2024. http://www.theses.fr/2024GRALI037.
Full textWith the aim of decarbonizing its energy mix and lowering its CO2 emissions, France has decided to invest massively in the decarbonized production of hydrogen as an energy carrier for mobility and stationary applications [1]. Of the one million ton of hydrogen produced in France, 96% is produced by steam reforming of hydrocarbons. France's strategy is to develop the hydrogen sector by investing in the installation of electrolyzers. What's more, the latest discoveries of huge deposits of natural hydrogen (46 million tons of hydrogen in Lorraine) are creating enthusiasm and expanding the field of prospects. [2]. Another decarbonated hydrogen production sector that is less talked about is the biological sector, which offers great potential for diversifying production routes. Hydrogen from these sources raises the question of its quality for use in mobility or stationary fuel cell systems.The aim of this thesis is to define strategies for the use of bio-hydrogen or natural hydrogen using proton exchange membrane fuel cell (PEMFC) technology, from hydrogen production to electrochemical conversion.The first part consisted in studying the impact of impurities or diluents (N2, Ar, He, CH4, CO2) contained in hydrogen from biological and native processes in a half-cell (gas diffusion electrode, GDE). This study was then extended to a single-cell proton exchange membrane fuel cell. Finally, a laboratory-scale biological reactor was used to produce hydrogen from organic sources by photo fermentation (PF), which was then tested in a GDE. Several electrochemical and physicochemical characterization techniques, such as cyclic voltammetry, chrono amperometry, CO stripping for electroactive surface measurement, scanning and transmission electron microscopy, ion chromatography, etc., were used to assess the performance of the PEMFC fed by bio-hydrogen, and its impact on fuel cell components.The results of the electrode activity for the hydrogen oxidation reaction in GDE revealed mass-transport limitation effects for the mixtures, with a particular behavior observed for the nitrogen mixture, and the methane and carbon dioxide mixtures, which in addition to dilution have a carbon monoxide poisoning effect on the electrode.Next, single-cell tests using H2/Ar, H2/N2 and H2/CO2 mixtures at 30 and 40% H2 by volume for stationary applications revealed greater performance losses for the carbon dioxide mixture, while the argon and nitrogen mixtures performed almost equally well. These performance losses are due to electroactive surface losses.Finally, the production of biohydrogen by PF showed that the choice of biomass, pre-treatment and bacterial strain influenced the quality of the biogas produced and the electrochemical performances obtained from it without purification steps.References[1] « Présentation de la stratégie nationale pour le développement de l’hydrogène décarboné en France ». Consulté le: 11 janvier 2024. [En ligne]. Disponible sur: https://www.economie.gouv.fr/presentation-strategie-nationale-developpement-hydrogene-decarbone-france[2] « Le plus gros gisement d’hydrogène naturel du monde vient d’être découvert en France », SudOuest.fr. Consulté le: 11 janvier 2024. [En ligne]. Disponible sur: https://www.sudouest.fr/economie/energie/le-plus-gros-gisement-d-hydrogene-naturel-du-monde-vient-d-etre-decouvert-en-france-17826239.php
Zamanillo, López Isabel. "Membranes hybrides pour pile à combustible." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAI120/document.
Full textFuel cell is a promising solution for clean production of hydrogen based energy. However to achieve a large-scale deployment of this technology, issues remain to be addressed. One of the remaining problems concerns the heart of the cell (polymer membrane sandwiched between two electrodes). We can stress the fact that it is impossible to improve the catalyst efficiency and the cell performance by a simple increase of the operating temperature (100-120 °C). Indeed the reference membrane (Nafion) exhibit a step decrease of its thermomechanical properties beyond 80 °C, whereas alternative membranes (with a better thermomechanical stability) are victims of a much faster chemical aging resulting into unexpected failure of the device.Our main objective is to develop novel hybrid membranes consisting of a commercial ionomer matrix in which we will introduce precursors capable to form a sol-gel phase. It will result on membrane composed of two interpenetrating phases, an ion conductive non-crosslinked polymer phase and a crosslinked inorganic phase providing chemical and thermomechanical stabilization. The control of the chemistry of this sol-gel phase, its morphology and its location in the membrane, which will improve the membrane properties, are essential to consider the development of these membranes for fuel cells.A careful analysis of the hydrothermal treatment effect on the microstructure of sPEEK membranes has been performed. Thanks to this analyse we can relate the microstructure with the functional properties of the polymer. The sol-gel process enables the growth of the sol-gel phase without disturbance of the initial nanostructured membrane. This strategy makes possible to control the distribution and morphology of the inorganic phase.The elaboration process of hybrid membrane has been studied. We presented the influence of elaboration parameters regarding the best conditions to prepare an optimized hybrid membrane. The physical and chemical properties of the inorganic phase were evaluated by many techniques (SANS, IR, DMA, etc.). The influence of the chemical structure (cross-linking degree) of the sol-gel network andthe impact of the sol-gel content and its distribution (morphology) into the host membrane on their functional properties is presented. We observed the great influence of cross-linking degree and of the amount of sol-gel present in the membrane which determines the functional properties of the membrane
Delhorbe, Virginie. "Elaboration de membranes pour piles à combustible à architecture réseaux (semi-)interpénétrés de polymères." Thesis, Cergy-Pontoise, 2011. http://www.theses.fr/2011CERG0512/document.
Full textThe polymer membranes currently used in fuel cells are reducing their performance at high temperature (T > 90°C) and low relative humidity (RH < 50%) [1]. This decrease is mainly due to loss of mechanical properties and conduction in these conditions. To overcome these drawbacks, unique membranes having an architecture (semi-) interpenetrating polymer network [2] ((semi-) IPN) in which a hydrophobic network is associated with a hydrophilic network, were developed under PAN-H “AMEIRICC” ANR Project.These membranes consist of fluorinated network ensuring the mechanical and sulfonated polyelectrolyte network ensuring the proton conduction of material, each network being derived from different precursors provided by IAM and LMOPS. After the polymerization/cross linking reaction of the two systems, materials are characterized to carry out a rapid return on their synthesis and optimize it to achieve a material with the main properties (proton conductivity, thermal and chemical stability, primarily). Once the synthesis is optimized, the first materials were provided to LMPB, SPrAM and LITEN for validation of selected membranes.The structural properties and conductivity values of materials led to the conclusion that (semi-) IPN have a similar morphology to that described for the Nafion in which the fluorous phase and the ionic conducting phase are co-continuous.Then several series of these membranes were conducted by changing the chemical composition in order to study the variation of obtained material properties. Finally, the first fuel cell test of original membranes have shown promise.[1] R. Borup, J. Meyers, B. Pivovar, Chem. Rev. 107 (2007) 3904.[2] L. H. Sperling and V. Mishra. The current status of interpenetrating polymer networks. In: Kim SC, Sperling LH, editors. IPNs around the world: science and engineering. New York: Wiley; 1997: p. 1-25
Molmeret, Yannick. "Mise en forme par extrusion de polymères fonctionnels conducteurs protoniques : polysulfones sulfones/liquides ioniques : application dans le domaine des piles à combustible." Grenoble INPG, 2010. http://www.theses.fr/2010INPG0040.
Full textThe research presented here was conducted in the CLIPPAC project that was a part of the national French project National Plan for Hydrogen (PAN-H) in 2005. This ambitious study was conducted between nine labotaries and an industrial partner, with the objective of finding an innovative solution to one of the main obstacles found in the PEMFC development : the working temperature. New material development that could be used in high temperature PEMFC is ambitious, but it would allow to increase the thermal resistance of the polymers used and at the same time would allow us to try to decrease the price of such material by integrating the question of their elaboration and processing in the same study. The path we followed consists in the joint used of Protonic Conductive Ionic Liquids (PCILs) incorporated in a conductive polymer membrane made of sulfonated polysulfone (SPSu). The PCIL should boost the conductivity of the material, while the polymeric membrane will maintain good mechanical properties. The PCILs study showed that different parameters are linked to good conductivity performances, such as the anion strength and size. We then chose to use the extrusion process to produce the membrane. This process well used in the polymers industry is innovative in the field of high properties polymers, since it is hard to maintain the polymers properties throughout the extrusion. The modus operandi we chose was to use the PCIL as a permanent aid-process plasticizer that allows us to produce in a single operation a membrane filled with a conductive ionic liquid
Roche, Ivan. "Catalyseurs de piles à combustible à membrane polymère échangeuse anionique." Grenoble INPG, 2007. http://www.theses.fr/2007INPG0010.
Full textThe electrocatalytic properties of materials for electrodes of Alkaline Fuel Cell were studied with their composition and morphology. Dispersed silver nanoparticles were synthesized by chemical Impregnation on various commercial carbons: the catalysts Ag/Monarch 1000 exhibit better massic activites towards the Oxygen Reduction Reaction (ORR) than the benchmark Ag/Vulcan XC72 (E-TEK). MnOx nanoparticles were also synthesized by chemical deposition on carbon. Me-doped (Me = Ni, Mg) MnOx/C exhibit ORR activity close to the benchmark catalyst 10 wt. % Pt/C (E-TEK), and yield quantitative formation of OH- (4-electron pathway). An ORR mechanism on MnOJC is suggested
Morizur, Vincent. "Fonctionnalisation de polymères et applications dans les domaines de l’énergie, de la catalyse, de la cosmétique et de la santé." Thesis, Nice, 2014. http://www.theses.fr/2014NICE4102.
Full textPolymers are now being studied in many fields such as chemistry, biochemistry, nanotechnology, electronics, medicine or material science and have applications in areas such as automotive industry, food industry, fine chemistry. The objective of this thesis is to achieve the functionalization of polymers and modify the properties of these materials in order to consider new applications. We were interested in polymers with the poly(aryl ether) motif, more particularly poly(ether ether ketone) (PEEK). This polymer is known for its mechanical, thermal, electrical properties and for its resistance to chemicals. In the first chapter, we present the functionalization of different polymers by sulfonyl chloride, sulfonic acid and sulfonamide functions. The second chapter is devoted to the synthesis and electrochemical study of novel polymeric electrolytes and new membranes for potential applications in the field of lithium and sodium batteries, as well as in the field of fuel cells. In the third chapter, the preparation of new metal catalysts derived from polymeric sulfonic acids is discussed. A study of the catalytic activity of these different polymeric catalysts was carried out on the Friedel-Crafts acylation reaction. The fourth chapter is devoted to the preparation of new materials with interesting optical properties. Finally, in the fifth chapter, the preparation and the study of new materials with antibacterial properties are reported
Coulon, Romain. "Modélisation de la dégradation chimique de membranes dans les piles à combustibles à membrane électrolyte polymère." Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00767412.
Full textBesson, Arthur. "Etude de polymères pour l'utilisation en membranes de piles à combustible." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENI070/document.
Full textFuel cells are an ever-expanding technology in the field of automotive transport. The polymer membranesthat are currently the most widely used are Nafion-based membranes. Their weakest point is their drastic lossof performances beyond the threshold of 80°C, where the membranes fails and water cannot ensure protonconduction anymore. The EUBECELLproject sets to achieve making a fuel cell system functioning above120°C and using ethanol as a fuel. This thesis is part of the project and focus on elaborating new protonconductingpolymer membranes. Two main ways are explored: improving the performances of Nafion athigh temperature and replacing Nafion with conductivity-added high-performance polymers.Improving Nafion's performances is achieved by adding proton conducting ionic liquids (PCILs), productsthat have a proton conductivity that adds to Nafion's own. A first PCIL is synthesized, characterized and thenadded to Nafion, the resulting membranes' performances then measured. The encouraging results that weobtain makes us synthesize more PCILs, from the same amine than the first, varying the counter-ion. OtherNafion-PCIL mixes are made and then characterized.The high-performance polymer investigated for replacing Nafion are, first, sulfonated polysulfones.Polysulfones are high-temperature resistant polymers and sulfonation gives them conductivity. To keep betterproperties after the sulfonation, we proceed to extrude the films before sulfonating them. We elaborate anheterogeneous sulfonation protocol for them. The resulting membranes are then characterized and theirperformances measured. Second, we work on macroporous membranes, with high mechanical strength,which we fill with the PCILs that we previously used. The membranes are then also characterized and theirperformances measured
Narducci, Riccardo. "Membranes conductrices ioniques pour piles à combustible." Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM4764.
Full textIn this thesis, perfluorosulfonic acid membranes (PFSA) and sulfonated aromatic polymers (SAP) are studied to better understandtheir thermodynamic, hydration, mechanical and electrical properties. The following main points were addressed:Regarding PFSA:1) Nafion membranes with various morphology and microstructure (amorphous, semi-crystalline, layered) were prepared and the relation to the properties, such as glass and melting transitions, and proton conductivity, was established.2) Various annealing treatments were performed and analyzed by the quantitative INCA (Ionomer nc Analysis) method using also special annealing agents. Regarding SAP:1) The in situ synthesis of cross-linked polymers was studied and the mechanism was clarified. 2) The degree of cross-linking was optimized for best proton conductivity.3) Cation-conducting ionomers were obtained by cation exchange of SPEEK and the properties of these new ionomers were determined
Akrour, Laurent. "Membrane échangeuse anionique et application en pile à combustible." Paris, CNAM, 2005. http://www.theses.fr/2005CNAM0493.
Full textThe 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
Laflamme, Patrick. "Caractérisation et conception de mélanges polymère/eau pour application aux piles à combustible utilisant une membrane polymère comme électrolyte." Thèse, Université de Sherbrooke, 2013. http://hdl.handle.net/11143/6685.
Full textStoica, Daniela. "Electrolytes polymères pour piles à combustible alcalines : mécanismes de conduction dans les membranes anioniques." Grenoble INPG, 2007. http://www.theses.fr/2007INPG0187.
Full textThe synthesis and characterizations of new membranes with anion conduction for alkaline fuel cells were realized. A study on model molecules permit to study the thermal and electrochemical stability of hydroxides quaternary ammonium. Polyepichlorhydrine membranes using quaternary ammoniums resulting from the DABCO and Quinuclidine or triméthylamine were characterized from a physico-chemical and electrochemical point of view. The effect of a woven support addition on the membrane properties was evaluated. The transport mechanism of OK, in this alkaline electrolyte, were thorough by correlating thermal, electrochemical, thermodynamic (phenomenon of sorption) and solid NMR measurements. New anion mémbranes were evaluated. The syntheses and physicochemical characterizations of these new membranes was carried out. Two membranes families were studied: membranes with rigid macromolecular skeleton : polysulphone or polyphenylene skeleton and a membrane with an elastomeric skeleton: a copolymer of polyoxyethylene
Ennajdaoui, Aboubakr. "Optimisation des conditions de synthèse par CVD plasma de membranes conductrices de protons pour piles à combustible." Phd thesis, Université d'Orléans, 2009. http://tel.archives-ouvertes.fr/tel-00503877.
Full textKOSMALA, BARBARA. "Separation et caracterisation de membranes echangeuse d'ions, basees sur des polymeres aromatiques pour pile a combustible." Paris 6, 2001. http://www.theses.fr/2001PA066132.
Full textDanyliv, Olesia. "Nouvelles membranes à squelette haute performance pour les piles à combustible PEMFC." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAI026/document.
Full textThe current work is directed to production of a proton conducting membrane for a proton electrolyte membrane fuel cell (PEMFC) as a main goal. The originality and the challenge of the membrane elaboration lie in the multi-step procedure: starting with the synthesis of a simple unit – an ionic monomer, continuing with polymerization and overall estimation of the polymer performance at laboratory scale, and ending with production of the required material of industrial quantity and testing in real conditions. All the steps, except the last one, are explicitly studied. Firstly, much attention in the dissertation is paid to description of a protocol for production and purification of the ionic monomers. It is due to complexity of ionic interactions in a system ‘product-solvent' and due to the main requirement of high purity for a monomer that attentive synthesis and treatment of the monomers must be provided. In total three new monomers, bearing perfluorosulfonic acid chains, are reported. Then, a number of polymerization reactions with different commercial non-ionic monomers are proposed. Two main families of proton conducting ionomers are described: random poly(arylene ether)s (PAEs) and poly(arylene ether sulfone)s (PAESs), both random and block-copolymers. They are synthesized in series of different IEC in order to follow the impact of the ionic group to the properties of the material. Additionally, a new structure of the ionomer is proposed, where the block-copolymer contains a hydrophilic block, synthesized from two monomers, bearing perfluorosulfonic acid (PFSA) groups. It allows maximally approximating the superacid lateral groups along the polymer chain that, most probably, contributes to better organization and interaction between the ionic sites. For further characterization of the novel polymers, they are cast to membranes by casting-evaporation method from their solutions in dimethylacetamide (DMAc). The influence of production temperature is described briefly. The membranes of different series are compared between each other and to Nafion as a reference material. It is known that Nafion acquires its high performance due to: i) presence of superacid PFSA lateral groups, and ii) organization of polymer chains into well-separated proton-conductive (hydrophilic) and mechanically stable (hydrophobic) domains. However, production of this material comprises dangerous and expensive procedures of manipulation with fluorinated gases, since this ionomer contains a Teflon-type backbone. Moreover, transition temperature of the perfluorinated main chain is lower, than the required temperature of the ionomer functioning in a PEMFC. The novel ionomers are further characterized in terms of thermo-mechanical properties, stability, conductivity, bulk morphology. They exhibit: i) high transition temperatures, which allows utilization of these polymers at conditions of a PEMFC functioning; ii) phase separation phenomenon, which suggests the materials to have morphology with distinct domains for proton conduction, iii) highly organized structuring, which is rare to clearly evidence on aromatic materials; iv) high proton conductivity for several polymer series, which over-perform Nafion even at reduced humidity. Based on these results, some of the synthesized materials are considered to be promising in a PEMFC, but further study in real conditions must be provided. Additionally, the current work is pioneering in the way of production of the ionomers, therefore, more different series of polymers are previewed to be synthesized out of the ionic monomers, proposed here. Variety of the ionic monomers may be enlarged as well by changing the PFSA groups to perfluorosulfonimide ones or by searching for other fluorinated commercial materials that might be modified into monomers with two functional groups for polycondensation. Thus, the main objectives, set for the current work, are fulfilled
Kreisz, Aurélien. "Membranes PBI pour pile à combustible haute température." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT224.
Full textThe thesis begins with a short overview of the principles and the current state at the art of the PEMFC in order to give a background on the specific subject of high temperature PEM fuel cell. The aim of the work presented in this thesis is to develop a new method of preparation of membrane for high temperature fuel cell (T > 120 °C). Phosphoric acid doped PBI has become the reference for high temperature PEM. A high phosphoric acid content is essential to minimize the ohmic voltage loss in the fuel cell for high current density. Unfortunately high phosphoric acid content exerts a strong plasticizing effect resulting in poor mechanical properties of the membrane. Consequently the doping level of the membrane should be a compromise between the highest proton conductivity and mechanical strength. In this work we have presented a new method of preparation of membrane based on the thermoreversible gelation of a PBI solution in phosphoric or polyphosphoric acid in order to obtain high acid doping. The chemical modification of the membrane has been performed in the doped state in order to induce a chemical crosslinking. The mechanical strength of the membrane has been further improved by the introduction of PBI electrospun mat as reinforcement. The feasibility of the approaches followed in this work was demonstrated in fuel cell tests at temperature up to 180 °C. The MEA based on those membranes have shown a stability up to 900 - 1000 hours either under static (continuous operation at 0.2 A.cm-2) or dynamic (voltage and current cycling) operation with a small voltage decay of 0.7 - 0.8 µV.h-1 at 0.2 A.cm-2. The I-V characteristics of these MEA have been compared with reference commercial PBI/H3PO4 MEAs and shown improved performances
Rubatat, Laurent. "Nouveau modèle structural des membranes Nafion ®, polymère de référence pour l'application pile à combustible basse température." Université Joseph Fourier (Grenoble), 2003. http://www.theses.fr/2003GRE10142.
Full textTran, 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.
Full textIn 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
Ayad, Abdelkader. "Étude comparative des membranes polymères échangeuses de protons : application aux électrodes à air pour pile à combustible." Paris, CNAM, 2003. http://www.theses.fr/2003CNAM0472.
Full textAlthough the Nafion membrane shows all the characteristics necessary for the correct operation of the fuel cells, its high manufacturing cost contributes to the development of the new ionic membranes. Our study will be focused en the physicochemical and electrochemical characterization of new protonic conducting polymers mainly sulfonic polyimide (PIS), the sulfonic polyetheretherketon (Peek-s), and the nonsulfonic polybenzimidazole (PBI) and the influence of these polymers on the kinetics of reduction of oxygen on platinum. For each polymer, except the PBI, the water content and the conductivity are of the same order than those of Nafion. The oxygen permeability is higher in Nafion than in other polymers. The diffusion coefficient in different polymers is lower than in solution (H2SO4 0,5M). Consequently the oxygen concentration in polymer is higher than that in solution, which is benefit to the oxygen reduction. The kinetic parameters of the oxygen reduction such as the exchange current and the number of transferred electrons remain unchanged with or without polymer. The optimal rate of polymer incorporated in the active matter evolues according to its nature: it is around 25% for Nafion, and around 15% for Peek-s and PIS. The fuel cell experiments show the need for having a good adhesion between the membrane and the electrode, but also the need for integratining a polymer presenting the appropriate physico-chemical characteristics in the membrane and the electrode. In conclusion, Peek-s seems to be the best alternative to Nafion
Riffault, Benoît. "Synthèse et propriétés de transport de membranes polymères pour piles à combustible de type PEMFC." Caen, 2005. http://www.theses.fr/2005CAEN2053.
Full textPérez, Hernandez Bartolo. "Réalisation et étude d'une maquette de pile à combustible à membrane anionique." Paris, CNAM, 2005. http://www.theses.fr/2005CNAM0494.
Full textA broad experimental study on fabrication of an anionic membrane fuel cell has been done. For this, each elements from this one has been studied, especially those which produced pronounced ohmics drops. So, the membrane and electrodes in half cell (alkaline medium) were studied. Electrode-membrane-assembly (MEA) were tested with an in housing experimental fuel cell in 1. 131 cm² active area. The employed membrane was synthesized in DMF with DABCO and Zeon polymer. The resistance of this membrane was significant and limited the fuel cell performance. A new membrane synthesized in H2O/DMF (70/30) has been proposed. The properties of this one allowed the MEA fabrication compressed at 87 bar and 20°C. The current density at steady state at 0. 1 V was 358 mA/cm² and the maximum fuel cell power was 28 mW/cm²