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Influence of the co...
Influence of the composition on the structure and electrochemical characteristics of the PEFC cathode
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- Gode, Peter (författare)
- KTH,Kemiteknik
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- Jaouen, Frederic (författare)
- KTH,Kemiteknik
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- Lindbergh, Göran (författare)
- KTH,Kemiteknik
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- Lundblad, Anders (författare)
- KTH,Kemiteknik
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- Sundholm, Göran (författare)
- KTH,Kemiteknik
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(creator_code:org_t)
- Elsevier BV, 2003
- 2003
- Engelska.
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Ingår i: Electrochimica Acta. - : Elsevier BV. - 0013-4686 .- 1873-3859. ; 48:28, s. 4175-4187
- Relaterad länk:
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https://urn.kb.se/re...
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https://doi.org/10.1...
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Abstract
Ämnesord
Stäng
- The influence the composition of the cathode has on its structure and electrochemical performance was investigated for a Nafion content spanning from 10 to 70 wt.%. The cathodes were formed on a Nafion membrane by the spray method and using 20 wt.% Pt on Vulcan (E-TEK). Materials characterisation (SEM, STEM, gas and mercury porosimetry, electron conductivity) and electrochemical characterisation (steady-state polarisation curve, impedance spectroscopy in O-2 and current-pulse measurements in N-2) were performed. The impedance spectra were analysed using our dynamic agglomerate model. The results indicate that the agglomerate model is valid until a Nafion content of about 45 wt.%. Pt/C and Nation are homogeneously mixed for any composition and no Nafion film was observed. The cathodes containing 36-43 wt.% Nation display a single or double Tafel slope behaviour ascribed to diffusion limitations in the agglomerates. At larger Nation content, the agglomerate model can describe the curves only by assuming a diffusion coefficient 3-4 decades smaller than that of gases. At such compositions, the porosity was only 10%. These results were interpreted as a blocking of the pores and a non-percolating pore system for too large Nafion contents.
Ämnesord
- NATURVETENSKAP -- Kemi (hsv//swe)
- NATURAL SCIENCES -- Chemical Sciences (hsv//eng)
Nyckelord
- PEFC cathode
- nafion content
- electrochemical characterisation
- material characterisation
- agglomerate model
- electrolyte fuel-cells
- gas-diffusion electrodes
- mass-transport limitations
- catalyst layer
- performance
- Chemistry
- Kemi
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
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