Comparative study of protonic conducting polymers incorporated in the oxygen electrode of the PEMFC

Ayad, Anas Iben; Bouet, J.; Fauvarque, Jean‐François

doi:10.1016/j.jpowsour.2005.02.044

Cited by 24 publications

(16 citation statements)

References 14 publications

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“…It is clearly evident by comparing the O 2 permeability of Nafion ® and SPEEK from Table I and II that SPEEK has atleast one order of magnitude lower value than Nafion ® . This is in agreement with other reports in the literature (9). The O 2 permeability in Nafion ® is invariant with the membrane temperature and relative humdity except at 40 o C and 100%RH.…”

Section: Resultssupporting

confidence: 93%

In Situ Measurement of Oxygen Permeability in Polymer Electrolyte Membranes

Sambandam¹,

Ramani²

2009

ECS Trans.

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Oxygen permeability in polymers (Nafion® and Sulfonated polyether ether ketone or SPEEK) was measured in-situ using a cylindrical Pt microelectrode by chronoamperometry at conditions mimicking actual fuel cell operation. The micro electrode (working electrode) reduces instantaneously any oxygen permeating through the polymer by changing to a potential at which oxygen transport is limited by diffusion. From the current profile corresponding to the potential hold, diffusivity and concentration of oxygen in the polymer was estimated. Durability of fuel cell membrane has been a long standing issue in fuel cell commercialization. Two modes of membrane decay widely reported in the literature are formation of (i) H2O2 and its subsequent decomposition to yield radicals and (ii) O2 reduction reaction intermediates. Viability of the use of Pt microelectrode in detection of H2O2 in both liquid and solid electrolytes was also studied. In both cases H2O2 was forcibly added to the system.

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Section: Resultssupporting

confidence: 93%

In Situ Measurement of Oxygen Permeability in Polymer Electrolyte Membranes

Sambandam¹,

Ramani²

2009

ECS Trans.

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“…This observation was consistent with the lower O 2 permeability of hydrocarbon binders as compared to PFSA materials. 59 In terms of kinetic parameters, the corrected Tafel slope for PFSA based MEAs ranged from 80 to 90 mV/decade while that of hydrocarbon based MEAs ranged from 100 to 120 mV/decade. There was not a clear trend seen with IEC, conductivity or O 2 permeability.…”

Section: Discussionmentioning

confidence: 98%

Influence of binder properties on kinetic and transport processes in polymer electrolyte fuel cell electrodes

Sambandam

Ramani

2010

Phys. Chem. Chem. Phys.

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The objectives of this study are to estimate the contributions of kinetic, ohmic and mass transport overpotentials to the overall voltage loss in polymer electrolyte membrane fuel cell (PEMFC) electrodes and to relate these overpotentials to electrode binder properties such as ionic conductivity, ion exchange capacity (IEC) and O(2) permeability. The model electrode binders studied were perfluorosulfonic acid ionomers (PFSA; of IECs 1.35 meq g(-1) and 0.95 meq g(-1)), sulfonated poly ether ether ketone (SPEEK; of IECs 1.35, 1.75 and 2.1 meq g(-1)) and sulfonated poly sulfone (SPSU; of IEC 1.5 meq g(-1)). The O(2) permeability of these binders varied from 0.15 x 10(-12) mol cm(-1) s(-1) for SPSU to 6 x 10(-12) mol cm(-1) s(-1) for PFSA IEC 0.95 meq g(-1) at 80 degrees C and 75%RH. The electrodes prepared were characterized by cyclic voltammetry to estimate electrochemically active surface area (ECA) of platinum. Steady state polarization (V-I) experiments were performed with hydrogen as fuel and oxidants including O(2), 21% O(2)/N(2) (air), 21% O(2)/He (Helox) and 4% O(2)/N(2). The V-I data obtained was analyzed to determine the relative contributions of the different sources of polarization in the electrode. Electrodes prepared with PFSA binders had similar ECAs of 28 m(2) g(-1)-Pt, while those prepared using hydrocarbon binders had an ECA of 10 to 14 m(2) g(-1)-Pt at 80 degrees C and 75%RH. The same trend was seen in mass activity. At optimized binder loadings, a semi-quantitative relationship was obtained relating binder O(2) permeability to the mass transport losses within the electrode. Furthermore, a novel semi-quantitative method of plotting helox-air voltage gain against O(2)-air gain was employed to probe the O(2) transport limitations in the electrodes. Based on this analysis, it is suggested that the SPEEK and SPSU bound electrodes suffered from binder phase diffusion limitations in addition to gas phase diffusion limitation, while the PFSA bound electrodes predominantly exhibited gas-phase diffusion limitations.

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“…Hydrocarbon components that have been used are sulphonated polysolphone (PSF), polyetersulphone (PES), polyetereterketone (PEEK) (Ayad et al, 2005), poly(imides) (PI) and poly (4-penoxibenzoil-l ,4-phenilene) (PPBP). Hydrocarbon membrane is stable at high temperature.…”

Section: Composite Electrolyte Membrane Based On Hydrocarbon-inorganimentioning

confidence: 99%