The present work focuses the attention on the development of micro-porous layers (MPLs) based on Fluorolink (R) P56 (Solvay Solexis S.p.A., Italy), a commercially available, anionic, segmented polyfluorourethane with high molecular weight. The samples have been produced by varying several parameters, such as polymer content, solvent for the ink and gas diffusion layer substrate. Tests were performed in a single fuel cell at the lab scale in order to evaluate electrochemical properties of the gas diffusion media (GDM) obtained. The cell testing was run at both 60 and 80 degrees C with two different relative humidities (RHs) of the feeding gases: 80/60% and 80/100%, for hydrogen and air respectively. The assessment of new MPLs performances was performed by using AC Electrochemical Impedance Spectroscopy (EIS) of the running cell. The EIS spectra were recorded at OCV and from low to high current density (i.e. 0.18, 0.37, 0.56, 0.76 and 0.94 A/cm(2)).
Il lavoro di tesi riguarda la produzione di strati microporosi (MPL) per celle a combustibile a membrana polimerica mediante l’impiego di Fluorolink (R) P56 (Solvay Solexis), un polifluorouretano anionico ad alto peso molecolare disponibile commercialmente. Sono stati preparati diversi campioni, analizzando gli effetti legati alla variazione della concentrazione del polimero, del solvente impiegato per la realizzazione degli inchiostri e del substrato diffusivo macroporoso (GDL) su cui sono state effettuate le deposizioni. I gas diffusion media (GDM) ottenuti sono stati testati in una cella a combustibile a membrana polimerica a scala di laboratorio a due differenti condizioni di umidità relativa (relative humidity, RH) dei gas alimentati (80%-60% e 80%-100% per idrogeno e aria rispettivamente) e a due temperature (60 e 80 gradi centigradi). Gli MPL realizzati hanno garantito l’ottenimento di buone prestazioni in cella e, al fine di valutare l’entità dei parametri elettrochimici, è stata predisposta un’analisi di spettroscopia di impedenza (EIS), con ottenimento dei relativi spettri in modalità galvanostatica da corrente nulla (OCV, open circuit voltage) ad alti valori di densità di corrente (i.e. 0.18, 0.37, 0.56, 0.76 and 0.94 A/cm(2)).
Preparazione e caratterizzazione di gas diffusion media con perfluoropolieteri
BALZAROTTI, RICCARDO
2011/2012
Abstract
The present work focuses the attention on the development of micro-porous layers (MPLs) based on Fluorolink (R) P56 (Solvay Solexis S.p.A., Italy), a commercially available, anionic, segmented polyfluorourethane with high molecular weight. The samples have been produced by varying several parameters, such as polymer content, solvent for the ink and gas diffusion layer substrate. Tests were performed in a single fuel cell at the lab scale in order to evaluate electrochemical properties of the gas diffusion media (GDM) obtained. The cell testing was run at both 60 and 80 degrees C with two different relative humidities (RHs) of the feeding gases: 80/60% and 80/100%, for hydrogen and air respectively. The assessment of new MPLs performances was performed by using AC Electrochemical Impedance Spectroscopy (EIS) of the running cell. The EIS spectra were recorded at OCV and from low to high current density (i.e. 0.18, 0.37, 0.56, 0.76 and 0.94 A/cm(2)).File | Dimensione | Formato | |
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2012_12_BALZAROTTI.pdf
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Descrizione: Testo della tesi
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https://hdl.handle.net/10589/72686