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Institute of Energy and Climate Research

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Applied electro-chemistry

• Characterization of fuel cells
• Corrosion of bipolar plates
• Model development

Fuel cells are electro-chemical membrane reactors, which convert chemical energy into electrical energy. Efficiency and power of these reactors depend on ‘conventional’ operation parameters like temperature and mass flow as well as on electro-chemical properties like catalyst utilization and ionic conductivity of the membrane. Fuel cells have a complex inner structure where the fluid flow has a strong impact on the operation [1]. The characterization of single cells and stacks is conducted with the aid of test rigs. Electric properties like ohmic resistance of the fuel cell can be determined by impedance spectroscopy methods [2]. Fuel cells behave different under different operation conditions. This behaviour can be understood by studying the underlying physical phenomena [3,4].
The main characteristic of a fuel cell is its polarization curve (see Figure 1). The experimental investigations are supported by suitable modelling approaches. These models can describe normal operation conditions for the prediction of the fuel cell performance. Models can also be used as tools for the investigation of degradation mechanisms [5,6]. Another major topic is the characterization of corrosion phenomena, which occur at high electric potential [7].

Left - Single cell type HT-PEFC / Right - polarization curve (T = 160 °C, p = 101.325 kPa, stoichiometry = 2/2 hydrogen/ air, 3-fold serpentine with 16.65 cm2 active area, CELTEC P1000 MEA)Figure 1: Left - Single cell type HT-PEFC / Right - polarization curve (T = 160 °C, p = 101.325 kPa, stoichiometry = 2/2 hydrogen/ air, 3-fold serpentine with 16.65 cm2 active area, CELTEC P1000 MEA)


[1] F. Liu, M. Kvesić, K. Wippermann, U. Reimer, W. Lehnert; Effect of Spiral Flow Field Design on Performance and Durability of HT-PEFCs, Journal of The Electrochemical Society, 160 (8) F892-F897 (2013)

[2] K. Wippermann, C. Wannek,  H.-F. Oetjen, J. Mergel and W. Lehnert; Cell resistances of poly(2,5-benzimidazole)-based high temperature polymer membrane fuel cell membrane electrode assemblies: Time dependence and influence of operating parameters, J. Power Sources 195 (2010) 2806–2809

[3] F. Liu, S. Mohajeri, Y. Di, K. Wippermann, W. Lehnert; Influence of the Interaction between Phosphoric Acid and Catalyst Layers on the Properties of  HT-PEFCs, Fuel Cells, 14 (2014) 750-757

[4] U. Reimer, J. Ehlert, H. Janßen, W. Lehnert; Water distribution in high temperature polymer electrolyte fuel cells, Int. J. Hydrogen Energy 41 (2016) 1837-1845

[5] A. Kulikovsky, Analytical Modelling of Fuel Cells, Elsevier B.V. 2010

[6] U. Reimer, B. Schumacher, W. Lehnert; Accelerated degradation of high-temperature polymer electrolyte fuel cells – discussion and empirical modeling, J. Electrochemical Soc. 162 (2015) F153-F164

[7] V. Weissbecker, K. Wippermann, W. Lehnert; Electrochemical Corrosion Study of Metallic Materials in Phosphoric Acid as Bipolar Plates for HT-PEFCs, J. Electrochemical Soc. 161 (2014) F1437-F1447


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