Abstract
In this study, electrochemical impedance spectroscopy (EIS) is applied
in combination with cyclic voltammetry (CV) and current
density – cell voltage curves (iV-curves) to
investigate the processes contributing to the total impedance of a
polymer electrolyte
membrane electrolysis cell (PEMEC). iV-curves were
linear above 0.35 A cm−2 implying ohmic processes to be
performance limiting, however the impedance spectra showed three arcs
indicating three electrochemical
reactions at these conditions not to be purely
ohmic, but also to have capacitive properties. A hypothesis that the
composite
IrOx/Nafion anode catalyst layer causes
two of these arcs with a constant sum of resistance and current
constrictions cause the
third arc, is suggested. This hypothesis implies
that the total differential cell resistance at current densities above
0.35
A cm−2 is purely ascribed to protonic resistance in Nafion in this type of PEMEC.
Original language | English |
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Journal | Journal of The Electrochemical Society |
Volume | 164 |
Issue number | 13 |
Pages (from-to) | F1419-F1426 |
ISSN | 0013-4651 |
DOIs | |
Publication status | Published - 2017 |