Fuel Cell Diagnostics

Fuel cell characterization by various diagnostic methods and understanding of the function and lifetime behavior of fuel cell components for PEFC and HTPEFC's is the vision and the mission of the fuel cell diagnostic activity. This encloses the ex-situ characterization, the in-situ performance and durability testing, as well as the numerical modeling of the processes. The diagnostic methods comprise impedance spectroscopy, local gas phase analytics, in-situ tomographic characterization, as well as locally resolved electrochemical experiments on various scales. Active area of sub cm² single cells up to several 100 cm² stacks for mobile applications can be tested.

15 July 2011

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X-Ray Tomography of Water in Operating Fuel Cell

Polymer electrolyte fuel cells (PEFC) convert the chemical energy of hydrogen with a high efficiency (40-70 %) directly into electricity. The product of the overall reaction is water, produced at the cathode of the cell. The interaction of liquid water with the porous structures of the cell is one of the mechanisms in the PEFC that are commonly believed to be key for further optimization with regard to performance, durability and cost.

30 May 2012

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Flow modeling in gas diffusion layers of PEFCs at the micro- and mesoscale

he optimization of thermochemical and electrochemical conversion systems is of high importance for a sustainable energy future society. Of particular interest regarding the performance of polymer electrolyte fuel cells (PEFCs) is the study of the gas flow in the gas diffusion layers (GDL). More specifically, permeability and diffusivity measurements in a model PEFC under normal operating conditions are highly desirable. As laboratory-measurements of these quantities under such conditions are very demanding, an alternative is the use of computer-based simulations.

15 January 2010

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Local current measurement in PEFCs

Major barriers for a successful commercialization of Polymer Electrolyte Fuel Cells (PEFCs) are insufficient lifetime and high cost of platinum catalyst. A comprehensive understanding of aging and transport phenomena on all relevant length scales is a key to improve durability and to reduce precious metal loading. Flow fields as used in PEFCs for the distribution of the reactant gases over the electrode area cause inhomogeneities. The importance of down the channel inhomogeneities has been realized.

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