Book/Dissertation / PhD Thesis

FZJ-2018-06199

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Characterization of High Temperature Polymer Electrolyte Fuel Cells

Rahim, Y. (Corresponding author)FZJ*

2018
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag Jülich
ISBN: 978-3-95806-359-4

Please use a persistent id in citations: http://hdl.handle.net/2128/20111  urn:nbn:de:0001-2018120703

Abstract: A Fuel cell is a clean and efficient energy converting device. High temperature polymer electrolyte fuel cell (HT-PEFC) is a particular type of fuel cell which offers fuel flexibility and system level simplicity. It is considered to be a viable solution for the transition period from a fossil fuel based economy to a sustainable, renewable energy based economy due to its potential to be efficiently utilized in combined heating and power, transport and backup power applications where fossil fuels continue to play a significant role. This thesis concentrates on development of methods and strategies to quantify performance related electrochemical parameters in HT-PEFC membrane electrode assemblies (MEA) at the single cell level. Both commercial and in-house assembled MEAs are utilized for this purpose. The in-house assembled MEAs are used for characterizing the most important material parameters for the HT-PEFC MEAs such as the platinum (Pt) loading, cathode catalyst layer(CCL) thickness and the phosphoric acid doping level (PADL) of the MEA. The parameter settings for maximum cell performance are systematically determined. An MEA with these parameters is used for investigating the effect of hydrogen and oxygen content in the anode andcathode streams respectively on cell impedance.The commercial MEAs are used to study the effect of various operating conditions on fuel cell performance. The design of experiments (DoE) is utilized to analyze the effect of various operating conditions on four different MEAs and regression models for each of the MEAs are developed for a comparison of the effect of sample size on the accuracy of the regression models. It is determined that a small sample size is accurate enough for an initial screening design, which can reduce the experimental effort by one-sixth, thus saving valuable time and resources. An accelerated degradation study is conducted on two different commercial MEAs to study the dominant degradation mechanisms for the HT-PEFC MEA. Various stressors are used for both MEA types for 100 hours. Polarization curves, EIS data and cyclic voltammetry data before and after stressor operation are compared and analyzed. Thermal cycling, high temperature operation and high cathode stoichiometry are determined to be the most effective stressors related to loss of phosphoric acid, loss of platinum surface area and carbon corrosion as the degradation mechanisms.

Note: RWTH Aachen, Diss., 2018

---

Contributing Institute(s):

1. Elektrochemische Verfahrenstechnik (IEK-3)

Research Program(s):

1. 135 - Fuel Cells (POF3-135) (POF3-135)

Appears in the scientific report 2018

---

Database coverage:
;

---