Composite Membrane Analysis and Design

About

The team Composite Membrane Analysis and Design focuses on the heart of electrochemical energy conversion systems such as polymer electrolyte fuel cells and water electrolyzers: The polymer electrolyte. This part of a cell needs to conduct ions while being mechanically stable to ensure electric isolation between the two electrodes. This function needs to be maintained under elevated temperatures, high pressure, and while harsh electrochemical reactions take place.

Therefore, the membranes that act as polymer electrolytes need to be tailored toward high ionic conductivity and excellent thermal, mechanical, and chemical stability. One means to improve the properties of such a polymer electrolyte is the development of composite membranes: Membranes that contain additives or reinforcement layers to enhance, e.g., the resistance toward mechanical stress. In our team, we focus both on the development and the characterization of composite membranes.

Research Topics

Development of ion-conducting membranes with

  • Improved ionic conductivity
  • Improved mechanical properties
  • Reduced gas or fuel crossover
  • Reduced thickness

We produce membranes and membrane electrode assemblies using various techniques such as spray coating and doctor blading. Besides the electrochemical characterization of single cells, we employ imaging and spectroscopy tools like electron microscopy and confocal Raman microscopy to study the physical properties of membranes and electrodes. Our goal is to optimize the performance and longevity of membranes and membrane electrode assemblies for various applications in electrochemical energy conversion.

Contact

Dr. Thomas Böhm

IEK-11

Building HIERN-Cauerstr / Room 4009

+49 9131-12538168

Overview of our methods

Manufacturing of membranes and electrodes

We employ various techniques to produce membranes from ion exchange polymers and electrodes from catalyst nanoparticles, support, and binder. A key to efficient electrochemical energy conversion is the interface between the single layers, which is generated when they are sandwiched to form a membrane electrode assembly.

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Electrochemical characterization

We develop membrane electrode assemblies mainly for proton exchange membrane fuel cells and water electrolyzers. The main evaluation of these electrochemical energy converters is performed by single-cell testing. Electrochemical characterization is used to elucidate their performance and important parameters such as the electrochemically active surface area of the electrodes or the fuel crossover over the membrane.

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Imaging and spectroscopy

We use advanced imaging methods to evaluate the morphological, chemical, and transport properties of membranes and electrodes. For instance, the porosity of the electrode within a membrane electrode assembly can be investigated by 3D imaging using scanning electron microscopy, and the degree of chemical degradation of a membrane after fuel cell operation can be quantified by confocal Raman microscopy.

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We employ various techniques to produce membranes from ion exchange polymers and electrodes from catalyst nanoparticles, support, and binder. A key to efficient electrochemical energy conversion is the interface between the single layers, which is generated when they are sandwiched to form a membrane electrode assembly.

More

Team members

Team photograph (June 2022).
Axel Marth
Selected publications
Last Modified: 20.07.2022