1. T.C
KOCAELİ ÜNİVERSİTESİ
MÜHENDİSLİK FAKÜLTESİ
KİMYA MÜHENDİSLİĞİ BÖLÜMÜ
Electrochemical Characterization Methods
Electrochemical impedance spectroscopy
By
Ahmad Reshad Sonmez
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Kocaeli University

2. VACUUM-ASSISTED DRYING OF POLYMER
ELECTROLYTE MEMBRANE FUEL CELL
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3. OUTLINE:
 Vacuum pressure was applied to a PEMFC to dry the membrane
 The vacuum-drying performance
 " Electrochemical impedance spectroscopy
 " An equivalent circuit model
 " Experimental results
 conclusion
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4. INTRODUCTION:
 Polymer electrolyte membrane fuel cells (PEMFCs) convert hydrogen and oxygen into
electricity, producing heat and water as by product
 water redistribution after cooling This may be beneficial during operation as the membrane
must be hydrated in order to effectively conduct protons However, excess liquid water
build-up leads to blockages of critical reaction sites as well as gas re-routing
 Critical testing parameters include purge time, gas velocity, relative humidity, and surface
treatment of bipolar plates as these are coupling factor that impact a cells condition and
performance
 When fc is shout down some water is remain in fc
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5. EXPERIMENTAL SETUP:
 test cell with an active area of 8 mm x 15 cm
 Three parallel channels with 1 mm x 1 mm
 cell requires four 150 W heating elements
 GDL SGL 10 BC carbon GDL
 membrane is a Nafion 112 with a platinum loading of 0.4 mg cm -2
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Vacuum assisted method:

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8. RELATION BETWEEN THE BOILING POINT AND PRESSURE :
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10. Results:
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13. CONCLUSION:
 Vacuum-assisted drying of a PEM fuel cell is shown to be more effective when compared
to conventional N2 gas purging
 HFR relaxation indicate the water redistribution occurs after using dry N2 gas purging but
not for the vacuum-assisted drying method
 The high pressure vacuum-assisted drying was found to be the most effective e in
removing water in the membrane ,CL,GDL .
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