Research Group Dr. Reiner Mönig

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Microscopy and Mechanical Measurements

Microscopy

A prime task of microscopy is to examine materials in a highly precise manner and to observe their modification by various factors in real time. Light microscopy is employed to examine materials inside the electrolyte in real time. It alone offers the possibility of observing processes in real time in realistic surroundings. The technique is used, for example, to study lithium deposition under conditions comparable to those in real cells.

The scanning electron microscope is a versatile tool for studying materials at a high resolution. For battery materials, the focus is on materials sensitive to air that can be transferred using a special transfer system.

Mechanical Measurements

Mechanical tension is formed in electrode materials during the storage and removal of lithium. Since this stress can lead to damage, measurement of the stress is helpful in assessing the reliability of material. An effective means to conduct such experiments is the substrate curvature method, in which a thin film is observed on a carrier, in this case the substrate. If the film undergoes mechanical tension, the electrode film–substrate system curves slightly. By measuring the substrate curvature, the tension in the electrode film can be calculated. At HIU it is uniquely possible to conduct such measurements on the basis of composite electrodes such as used in real batteries.

 

Dr. Dominik KramerScientist Tel: +49 (0721) 608 24894Mail: dominik.kramer(at)kit.edu
ForschungsgruppeResearch Group Dr. Reiner Mönig
Dr. Reiner MönigPrincipal Investigator (PI)Tel: +49 (0721) 608 22487Mail: reiner.moenig(at)kit.edu
ForschungsgruppeResearch Group Dr. Reiner Mönig
Tel: Mail:
Forschungsgruppe
Tel: Mail:
Forschungsgruppe

(images will be uploaded shortly)

 

Light Microscopy

Light Microscopy is used to investigate materials inside the electrolyte in real time. Although the resolution of light microscopy is limited to about 300nm it offers the unique possibility the observe processes in real time in realistic environments. In our research we strongly rely on this technique for example for investigating lithium plating where the same solid electrolyte interface conditions as in real cells can be established. In this research we observe protrusion growth during lithium deposition and identify the governing mechanisms. In contrast to what is known from the literature we reveal that dendrite growth is controlled by defects and that concentration gradients or electrical fields or diffusion inhomogenities do not strongly affect the growth of dendrites.

 

Scanning Electron Microscopy

SEM is a versatile tool for investigating materials at high resolution. For battery materials care has to be taken about air sensitive materials which are transferred using a special transfer system. In our SEM setups we have two options. We can use a dedicated in situ cell that uses ionic liquid based electrolytes with very low vapor pressure to observer electrode materials in real time. This technique is particularly suitable for conversion or alloying materials where strong changes occur within the first or first few cycles. For higher cycle numbers we hae develop a technique that allows the inspection of an electrode region over the course of several hundred or thousands of cycles. In this experiment the cell is disassembled and reassembled after investigation and transfer to be tested for several weeks or even months. In this experiment we can compare the same electrode regions before during and after the tests.

 

Substrate Curvature Measurements

During insertion and extraction of lithium, mechanical stresses form in electrode materials. These stresses can lead to damage and therefore a measurement of these stresses is useful for assessing the reliability of a material. An effective way for performing such experiments is the substrate curvature technique, where a thin film on a relatively thick substrate is considered. If the film experiences mechanical stresses, the film substrate composite bends. By measuring the curvature of this system, the stresses in the film can be calculated. At HIU we have the unique possibility to perform such measurements on particle based composite electrodes as used in real batteries. In our experiments the electrodes are glued to borosilicate cantilevers and their bending is monitored. Our home-built setup has a very high sensitivity and measures at speeds of up to 30ms. Tracking the mechanical stresses not only helps to assess the mechanics of a material, since stress and electrochemistry are strongly coupled the measurements can also be used to monitor phase transformations or degradation effects.

(information will be uploaded shortly)

 

The research group uses the equipment below

  • Electron microscope Zeiss Merlin with EBSD und EDX and transfer system
  • three substrate curvature device with thermostatization
  • Raman Microscope and diffractometer

(images will be uploaded shortly)

 

The electron microscopy and spectroscopy group is partner in a number of national and international collaborations and projects. Battery related projects are pursued as part of the following projects.

MIT – Department of Materials Science and Engineering

There is a close cooperation with the research group of Prof. Carl V. Thompson, Department of Materials Science and Engineering, MIT.

Further information

Zeitschriftenaufsatz
Zheng T., Kramer Dominik, Tahmasebi M. H., Mönig Reiner, Boles S. T.
Learn more
Zeitschriftenaufsatz
Mandl Magdalena, Becherer Julian, Kramer Dominik, Mönig Reiner, Diemant Thomas, Behm R. Jürgen, Hahn Markus, Böse Olaf, Danzer Michael A.
Learn more
Zeitschriftenaufsatz
Tahmasebi Mohammad Hossein, Kramer Dominik, Geßwein Holger, Zheng Tianye, Leung Kwan-Chee, Lo Benedict Tsz Woon, Mönig Reiner, Boles Steven T.
Learn more
Zeitschriftenaufsatz
Tahmasebi Mohammad Hossein, Kramer Dominik, Mönig Reiner, Boles Steven T.
Learn more
Zeitschriftenaufsatz
Chen Di, Kramer Dominik, Mönig Reiner
Learn more
Zeitschriftenaufsatz
Biasi Lea de, Lieser Georg, Dräger Christoph, Indris Sylvio, Rana Jatinkumar, Schumacher Gerhard, Mönig Reiner, Ehrenberg Helmut, Binder Joachim R., Geßwein Holger
Learn more
Zeitschriftenaufsatz
Kondrakov A. O., Schmidt A., Xu J., Geßwein H., Mönig R., Hartmann P., Sommer H., Brezesinski T., Janek J.
Learn more
Zeitschriftenaufsatz
Al-Obeidi Ahmed, Kramer Dominik, Boles Steven T., Mönig Reiner, Thompson Carl V.
Learn more
Zeitschriftenaufsatz
Al-Obeidi Ahmed, Kramer Dominik, Mönig Reiner, Thompson Carl V.
Learn more
Zeitschriftenaufsatz
Steiger Jens, Richter Gunther, Wenk Moritz, Kramer Dominik, Mönig Reiner
Learn more
Zeitschriftenaufsatz
Al-Obeidi Ahmed, Kramer Dominik, Thompson Carl V., Mönig Reiner
Learn more
Zeitschriftenaufsatz
de Biasi L., Lieser G., Rana J., Indris S., Dräger C., Glatthaar S., Mönig R., Ehrenberg H., Schumacher G., Binder J. R., Geßwein H.
Learn more
Poster
Steiger J., Kramer D., Mönig R.
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Poster
Kramer D., Steiger J., Mönig R.
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Poster
Kramer D., Steiger J., Mönig R.
Learn more
Poster
Kramer D., Steiger J., Mönig R.
Learn more
Zeitschriftenaufsatz
Steiger J., Kramer D., Mönig R.
Learn more
Zeitschriftenaufsatz
Steiger J., Kramer D., Mönig R.
Learn more
Zeitschriftenaufsatz
Boles S. T., Thompson C. V., Kraft O., Mönig R.
Learn more
Poster
Kramer D., Steiger J., Mönig R.
Learn more
Poster
Choi Z., Kramer D., Mönig R.
Learn more
Poster
Chen D., Choi Z., Kramer D., Mönig R.
Learn more
Poster
Steiger J., Boles S., Kramer D., Mönig R.
Learn more
Zeitschriftenaufsatz
Choi Z., Kramer D., Mönig R.
Learn more
Poster
Steiger J., Kramer D., Mönig R.
Learn more
Mitglieder
Dr. Dominik KramerScientist Tel: +49 (0721) 608 24894Mail: dominik.kramer(at)kit.edu
ForschungsgruppeResearch Group Dr. Reiner Mönig
Dr. Reiner MönigPrincipal Investigator (PI)Tel: +49 (0721) 608 22487Mail: reiner.moenig(at)kit.edu
ForschungsgruppeResearch Group Dr. Reiner Mönig
Tel: Mail:
Forschungsgruppe
Tel: Mail:
Forschungsgruppe
Forschung

(images will be uploaded shortly)

 

Light Microscopy

Light Microscopy is used to investigate materials inside the electrolyte in real time. Although the resolution of light microscopy is limited to about 300nm it offers the unique possibility the observe processes in real time in realistic environments. In our research we strongly rely on this technique for example for investigating lithium plating where the same solid electrolyte interface conditions as in real cells can be established. In this research we observe protrusion growth during lithium deposition and identify the governing mechanisms. In contrast to what is known from the literature we reveal that dendrite growth is controlled by defects and that concentration gradients or electrical fields or diffusion inhomogenities do not strongly affect the growth of dendrites.

 

Scanning Electron Microscopy

SEM is a versatile tool for investigating materials at high resolution. For battery materials care has to be taken about air sensitive materials which are transferred using a special transfer system. In our SEM setups we have two options. We can use a dedicated in situ cell that uses ionic liquid based electrolytes with very low vapor pressure to observer electrode materials in real time. This technique is particularly suitable for conversion or alloying materials where strong changes occur within the first or first few cycles. For higher cycle numbers we hae develop a technique that allows the inspection of an electrode region over the course of several hundred or thousands of cycles. In this experiment the cell is disassembled and reassembled after investigation and transfer to be tested for several weeks or even months. In this experiment we can compare the same electrode regions before during and after the tests.

 

Substrate Curvature Measurements

During insertion and extraction of lithium, mechanical stresses form in electrode materials. These stresses can lead to damage and therefore a measurement of these stresses is useful for assessing the reliability of a material. An effective way for performing such experiments is the substrate curvature technique, where a thin film on a relatively thick substrate is considered. If the film experiences mechanical stresses, the film substrate composite bends. By measuring the curvature of this system, the stresses in the film can be calculated. At HIU we have the unique possibility to perform such measurements on particle based composite electrodes as used in real batteries. In our experiments the electrodes are glued to borosilicate cantilevers and their bending is monitored. Our home-built setup has a very high sensitivity and measures at speeds of up to 30ms. Tracking the mechanical stresses not only helps to assess the mechanics of a material, since stress and electrochemistry are strongly coupled the measurements can also be used to monitor phase transformations or degradation effects.

Equipment

(information will be uploaded shortly)

 

The research group uses the equipment below

  • Electron microscope Zeiss Merlin with EBSD und EDX and transfer system
  • three substrate curvature device with thermostatization
  • Raman Microscope and diffractometer
Zusammenarbeit

(images will be uploaded shortly)

 

The electron microscopy and spectroscopy group is partner in a number of national and international collaborations and projects. Battery related projects are pursued as part of the following projects.

MIT – Department of Materials Science and Engineering

There is a close cooperation with the research group of Prof. Carl V. Thompson, Department of Materials Science and Engineering, MIT.

Further information

Publikationen
Zeitschriftenaufsatz
Zheng T., Kramer Dominik, Tahmasebi M. H., Mönig Reiner, Boles S. T.
Learn more
Zeitschriftenaufsatz
Mandl Magdalena, Becherer Julian, Kramer Dominik, Mönig Reiner, Diemant Thomas, Behm R. Jürgen, Hahn Markus, Böse Olaf, Danzer Michael A.
Learn more
Zeitschriftenaufsatz
Tahmasebi Mohammad Hossein, Kramer Dominik, Geßwein Holger, Zheng Tianye, Leung Kwan-Chee, Lo Benedict Tsz Woon, Mönig Reiner, Boles Steven T.
Learn more
Zeitschriftenaufsatz
Tahmasebi Mohammad Hossein, Kramer Dominik, Mönig Reiner, Boles Steven T.
Learn more
Zeitschriftenaufsatz
Chen Di, Kramer Dominik, Mönig Reiner
Learn more
Zeitschriftenaufsatz
Biasi Lea de, Lieser Georg, Dräger Christoph, Indris Sylvio, Rana Jatinkumar, Schumacher Gerhard, Mönig Reiner, Ehrenberg Helmut, Binder Joachim R., Geßwein Holger
Learn more
Zeitschriftenaufsatz
Kondrakov A. O., Schmidt A., Xu J., Geßwein H., Mönig R., Hartmann P., Sommer H., Brezesinski T., Janek J.
Learn more
Zeitschriftenaufsatz
Al-Obeidi Ahmed, Kramer Dominik, Boles Steven T., Mönig Reiner, Thompson Carl V.
Learn more
Zeitschriftenaufsatz
Al-Obeidi Ahmed, Kramer Dominik, Mönig Reiner, Thompson Carl V.
Learn more
Zeitschriftenaufsatz
Steiger Jens, Richter Gunther, Wenk Moritz, Kramer Dominik, Mönig Reiner
Learn more
Zeitschriftenaufsatz
Al-Obeidi Ahmed, Kramer Dominik, Thompson Carl V., Mönig Reiner
Learn more
Zeitschriftenaufsatz
de Biasi L., Lieser G., Rana J., Indris S., Dräger C., Glatthaar S., Mönig R., Ehrenberg H., Schumacher G., Binder J. R., Geßwein H.
Learn more
Poster
Steiger J., Kramer D., Mönig R.
Learn more
Poster
Kramer D., Steiger J., Mönig R.
Learn more
Poster
Kramer D., Steiger J., Mönig R.
Learn more
Poster
Kramer D., Steiger J., Mönig R.
Learn more
Zeitschriftenaufsatz
Steiger J., Kramer D., Mönig R.
Learn more
Zeitschriftenaufsatz
Steiger J., Kramer D., Mönig R.
Learn more
Zeitschriftenaufsatz
Boles S. T., Thompson C. V., Kraft O., Mönig R.
Learn more
Poster
Kramer D., Steiger J., Mönig R.
Learn more
Poster
Choi Z., Kramer D., Mönig R.
Learn more
Poster
Chen D., Choi Z., Kramer D., Mönig R.
Learn more
Poster
Steiger J., Boles S., Kramer D., Mönig R.
Learn more
Zeitschriftenaufsatz
Choi Z., Kramer D., Mönig R.
Learn more
Poster
Steiger J., Kramer D., Mönig R.
Learn more

Group Facts