Analytical Investigation of Fuel Cells by Using In Situ and Ex Situ Diagnostic Methods

The study of the behaviour of fuel cells by using various in-situ and ex-situ diagnostic methods is a main topic at the German Aerospace Center (DLR). The degradation of cell components of polymer electrolyte fuel cells (PEFC, DMFC) and of solid oxide fuel cells (SOFC) are of special interest. For this purpose physical and electrochemical methods are used individually as well as in combination. In addition to routinely applied electrochemical methods different methods for locally resolved current density measurements by means of segmented cell technology and integrated temperature sensors have been developed. The latest development with segmented bipolar plates based on printed circuit boards (PCB) is used both in single PEFC cells and stacks. Furthermore, a measuring system for segmented SOFC cells has been developed allowing for the spatially resolved characterisation of cells in terms of current density/voltage characteristics, impedance spectroscopy data, operating temperature and gas composition. The paper summarises the capabilities at DLR with respect to the analysis of fuel cells’ behaviour and gives examples of analytical studies to discuss the potentials and limitations of the diagnostic methodology that is applied.

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Diagnostic Tools for In-situ and Ex-situ Investigations of Fuel Cells and Components at the German Aerospace Center

ECS Transactions ◽

10.1149/1.2728987 ◽

2019 ◽

Vol 5 (1) ◽

pp. 49-60 ◽

Cited By ~ 2

Author(s):

Mathias Schulze ◽

Erich Gülzow ◽

K. Andreas Friedrich ◽

Patrick Metzger ◽

Günter Schiller

Keyword(s):

Fuel Cells ◽

Ex Situ ◽

Diagnostic Tools ◽

German Aerospace

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A Scaling Method for Correlating Ex Situ and In Situ Measurements in PEM Fuel Cells and Electrolyzer

Journal of The Electrochemical Society ◽

10.1149/2.0041811jes ◽

2018 ◽

Vol 165 (10) ◽

pp. F883-F890

Author(s):

Hyun-Seok Cho ◽

Won-Chul Cho ◽

J. W. Van Zee ◽

Chang-Hee Kim

Keyword(s):

Fuel Cells ◽

Pem Fuel Cells ◽

In Situ Measurements ◽

Ex Situ ◽

Scaling Method

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Metamorphosis of the Mixed Phase PtRu Anode Catalyst for Direct Methanol Fuel Cells After Exposure of Methanol: In-situ and Ex-situ Characterizations

ECS Meeting Abstracts ◽

10.1149/ma2006-01/3/130 ◽

2006 ◽

Keyword(s):

Fuel Cells ◽

Direct Methanol Fuel Cells ◽

Mixed Phase ◽

Ex Situ ◽

Anode Catalyst ◽

Direct Methanol ◽

Methanol Fuel Cells

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In Situ and Ex Situ Characterization of PFSA-Inorganic Inclusion Composites for Medium Temperature PEM Fuel Cells

Advances in Science and Technology - 11th International Ceramics Congress ◽

10.4028/3-908158-01-x.787 ◽

2006 ◽

pp. 787-792

Author(s):

Felix Bauer ◽

Achim Müller ◽

Anna Wojtkowiak ◽

Monika Willert-Porada

Keyword(s):

Fuel Cells ◽

Pem Fuel Cells ◽

Ex Situ ◽

Medium Temperature

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Correlating Ex-Situ and In Situ Measurement for Proton Exchange Membrane Fuel Cells

ECS Meeting Abstracts ◽

10.1149/ma2014-01/14/656 ◽

2014 ◽

Keyword(s):

Fuel Cells ◽

Proton Exchange Membrane ◽

Proton Exchange ◽

In Situ Measurement ◽

Ex Situ ◽

Exchange Membrane

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Treatment of phenanthrene and benzene using microbial fuel cells operated continuously for possible in situ and ex situ applications

International Biodeterioration & Biodegradation ◽

10.1016/j.ibiod.2016.10.021 ◽

2017 ◽

Vol 116 ◽

pp. 91-103 ◽

Cited By ~ 27

Author(s):

Oluwaseun Adelaja ◽

Tajalli Keshavarz ◽

Godfrey Kyazze

Keyword(s):

Fuel Cells ◽

Microbial Fuel Cells ◽

Ex Situ

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In-Situ and Ex-Situ Investigation of Lateral Current Density Variations in a PEM Fuel Cell With Serpentine Flow Field

Volume 6: Emerging Technologies: Alternative Energy Systems; Energy Systems: Analysis, Thermodynamics and Sustainability ◽

10.1115/imece2009-12941 ◽

2009 ◽

Author(s):

Andrew Higier ◽

Hongtan Liu

Keyword(s):

Fuel Cell ◽

Flow Field ◽

Contact Resistance ◽

Current Density ◽

Pem Fuel Cell ◽

Gas Diffusion ◽

Operating Conditions ◽

Ex Situ ◽

Serpentine Flow Field

One of the most common types of flow field designs used in proton exchange membrane (PEM) fuel cell is the serpentine flow field. It is used for its simplicity of design, its effectiveness in distributing reactants and its water removal capabilities. The knowledge about where current density is higher, under the land or the channel, is critical for flow field design and optimization. Yet, no direct measurement data are available for serpentine flow fields. In this study a fuel cell with a single channel serpentine flow field is used to separately measure the current density under the land and channel on the cathode. In this manner, a systematic study is conducted under a wide variety of conditions and a series of comparisons are made between land and channel current density. Results show that under most operating conditions, current density is higher under the land than that under the channel. However, at low voltage, a rapid drop off in current density occurs under the land due to concentration losses. In order to investigate the cause of the variations of current density under the land and channel and series of ex-situ and in-situ experiments were conducted. In the ex-situ portion of the study, the contact resistance between the gas diffusion electrode (GDE) and the graphite flow plate were measured using an ex-situ impedance spectroscopy technique. The values of the contact resistance under the channel were found to be larger than that under the land. This implies that the contact resistance under the land and channel vary greatly, likely due to variations in compression under different section of the flow field. These variations in turn cause current density variations under the land and channel.

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