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Electrochemical Characterization of Low-Temperature DEFC using DC and AC Methods_PREPRINT.pdf (2.5 MB)
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Electrochemical Characterization of Low-Temperature Direct Ethanol Fuel Cells Using Direct and Alternate Current Methods

preprint
submitted on 05.07.2019 and posted on 05.07.2019 by Paweł Wnuk, Rafal Jurczakowski, Adam Lewera
Here we report for the first time the results of systematic characterization of a low-temperature polymer electrolyte membrane direct ethanol fuel cell using DC and AC electrochemical methods. Model catalysts (carbon supported Pt nanoparticles) painted on carbon paper are used as anode and cathode. Influence of physical parameters, such as cell temperature, current density, ethanol concentration and anode fuel flow rate on overall cell impedance is studied. Analysis of the obtained impedance spectra in connection with DC measurements allows us to comment on cell properties and to separate different contributions to the overall cell polarization. Our results suggest that the cell impedance is dominated by anode faradaic impedance, with negligible contribution from cathode faradaic impedance. The anode impedance depends strongly on current density and cell temperature, but is not significantly influenced by ethanol concentration. Presence of anode mass-transfer impedance, even when ethanol was fed to the cell in high excess, is confirmed. Based on the results we conclude that changes in ethanol electro-oxidation mechanism might manifest themselves on the impedance spectra in the low-frequency inductive loop. Nonetheless, further studies involving equivalent circuit modelling are needed to determine the exact influence of the cell parameters on the anode kinetics.

Funding

DEC-2013/09/B/ST4/00099

History

Email Address of Submitting Author

pawwnuk90@gmail.com

Institution

University of Warsaw

Country

Poland

ORCID For Submitting Author

0000-0002-7745-4460

Declaration of Conflict of Interest

Authors declare no conflict of intetrest.

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