electrochemical impedance spectroscopy
TRANSCRIPT
T.C
KOCAELİ ÜNİVERSİTESİ
MÜHENDİSLİK FAKÜLTESİ
KİMYA MÜHENDİSLİĞİ BÖLÜMÜ
Electrochemical Characterization Methods
Electrochemical impedance spectroscopy
By
Ahmad Reshad Sonmez
10.3.20151
Kocaeli University
VACUUM-ASSISTED DRYING OF POLYMER
ELECTROLYTE MEMBRANE FUEL CELL
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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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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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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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RELATION BETWEEN THE BOILING POINT AND PRESSURE :
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Results:
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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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