Relating the N-shaped polarization curve of a PEM fuel cell to local oxygen starvation and hydrogen evolution

authored by

Nada Zamel, Richard Hanke-Rauschenbach, Sebastian Kirsch, Arjun Bhattarai, Dietmar Gerteisen

Abstract

In this study, we experimentally investigate the appearance of a local negative differential resistance (N-NDR) branch in polarization curves of a segmented 7 by 7 cell measured under the steady and highly-dynamic conditions. Under both conditions, a comma shaped polarization curve, corresponding to depletion of oxygen, was followed by an increase in current as the cell voltage was lowered. This characteristic was measured under potentiostatic mode, where no current is forced through the cell, and at a positive cell voltage (<100 mV in steady-state and ∼300 mV in dynamic condition). With a theoretical model, we show that at these positive cell voltages and upon the depletion of oxygen, a shift in the Nernst potential occurs allowing for the hydrogen evolution reaction to take place in the cathode catalyst layer. The results of the model are complemented with experimental measurements of produced hydrogen at the cathode outlet.

External Organisation(s)

Fraunhofer Institute for Solar Energy Systems (ISE)
Max Planck Institute for Dynamics of Complex Technical Systems

Type

Article

Journal

International Journal of Hydrogen Energy

Volume

38

Pages

15318-15327

No. of pages

10

ISSN

0360-3199

Publication date

22.11.2013

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Renewable Energy, Sustainability and the Environment, Fuel Technology, Condensed Matter Physics, Energy Engineering and Power Technology

Sustainable Development Goals

SDG 7 - Affordable and Clean Energy

Electronic version(s)

https://doi.org/10.1016/j.ijhydene.2013.09.130 (Access: Unknown)