Research Group Prof. Christian Kübel

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Die Elektronenmikroskopie und Spektroskopie Gruppe am HIU ist eine interdisziplinäre Gruppe in der Physiker, Chemiker, Materialwissenschaftler und Geologen tätig sind.

Der Schwerpunkt unserer Arbeiten liegt in der Aufklärung der Struktur und Morphologie neuartiger Batteriematerialien und Komponenten, wofür wir eine Kombination aus direkt abbildenden Verfahren mit bis zu atomarer Auflösung und spektroskopischen Verfahren zur chemischen Charakterisierung verwenden. Ziel dieser Arbeiten ist es, in Zusammenarbeit mit den anderen Gruppen am HIU, ein Verständnis für den  Zusammenhang zwischen Struktur und elektrochemischen Eigenschaften und Stabilität zu entwickeln. Dazu arbeiten wir u.A. auch an der Entwicklung neuer  in-situ TEM Methoden, um die Strukturänderungen während dem elektrochemischen Zyklieren von miniaturisierten Batterien direkt abzubilden.

 

Prof. Dr. Christian KübelPrincipal InvestigatorTel: +49 (0721) 608 28970Mail: christian.kuebel(at)kit.edu
ForschungsgruppeResearch Group Prof. Christian Kübel
Dr. Georgian MelinteScientist Tel: +49 (0721) 608 26531Mail: Georgian.Melinte(at)kit.edu
ForschungsgruppeResearch Group Prof. Christian Kübel
Charlotte NeidigerPhD StudentTel: +49 (0721) 608 28925Mail: charlotte.neidiger(at)kit.edu
ForschungsgruppeResearch Group Prof. Christian Kübel
ForschungsgruppeResearch Group Prof. Christian Kübel

(images will be uploaded shortly)

 

Electron Microscopic Characterization of Batteries and Materials

The development of advanced materials for new batteries increasingly focuses on nanostructured composites to combine high electron and ion conductivity for new cathode materials. These nano composites typically exhibit a complex morphology geared to maintain high capacity over extended charging/discharging cycles. The aim of the electron microscopy & spectroscopy group is to characterize the morphology and composition of the active battery materials at the atomic to nanometer scale in 2D and also 3D using a combination of high-resolution imaging (TEM, HAADF-STEM), spectroscopy (EELS, EDX) and tomographic techniques to correlate the structure and morphology at different charging states with the cyclic stability. To some extent, this characterization is possible using well-developed ex-situ analytical (S)TEM techniques that only need to be optimized to deal with the electron beam sensitivity of most battery materials. However,for a more direct analysis of the structural changes during electrochemical cycling, we are also actively developing new techniques for in-situ imaging of micron/nano-sized battery models inside the TEM.

 

Metal fluorides as conversion electrodes in lithium ion batteries

In collaboration with Prof. Max Fichtner, we have characterized the structure of Fe/Lif/C conversion electrodes used as cathode materials in lithium-ion batteries. The conversion materials prepared pyrolysis of ferrocene with LiF initially consist of iron (and some iron carbide) nanoparticles with a thin graphitic shell, interconnected by MWCNTs.

Charging leads to the formation of FeF2/C or FeF3/C nanoparticles with the graphitic shell still present.
Both, the graphitic shell and the MWCNTs are crucial for a good cyclic behavior with the graphitic shell presumably responsible forthe cyclicstability of the iron nanoparticles and the MWCNTs ensuring electrical contact through the electrode.

 

Development of in-situ TEM characterization of the cyclic behaviour of solid state batteries

In addition to the ex-situ analysis shown above, we are developing new preparation and analysis approaches to follow the structural changes in micron sized solid state batteries and half cells in-situ using TEM techniques. The basic idea is to use FIB preparation to cut a thin cross-section from a solid state battery that is then transferred under (close to) inert conditions onto an electro-contacting TEM holder for in-situ analysis using low-dose and low voltage TEM and STEM techniques.

The materials currently under investigation are solid state lithium ion batteries with Garnet type electrolytes in collaboration with Prof. Jürgen Janek group at the University Giessen  and new lithium-free fluoride based solid state batteries in collaboration with Prof. Max Fichtner.

 

In-situ liquid in the TEM

As part of the development of the in-situ liquid experiments in the TEM, we have the possibility to introduce liquids between two SiN membranes using a Protochips Posseidon in-situ liquid flow holder along with electrical measurements. On the other hand, nanoparticles can also be generated in liquids inside the TEM induced through electron beam which is critical to differentiate from the actual experiment of interest.

(information will be uploaded shortly)

 

The electron microscopy and spectroscopy group is operating the following equipment at the Institute of Nanotechnology (INT) in Karlsruhe, which is available for research activities within HIU:

Laboratories

  • SEM, FIB and TEM laboratories
  • Metallography laboratory for SEM/TEM sample preparation
  • Sample preparation laboratory for battery materials with MBRAUN glovebox equipped with micromanipulator controlled sample handling
  • Image processing laboratory with specialized software for SEM and TEM image analysis and processing

Equipment

 

Transmission Electron Microscopes (TEM)

 

Transmission electron microscopy (TEM) enables characterization of materials by direct imaging with up to atomic resolution. The image information can be locally correlated with spectroscopic techniques (EELS/EFTEM and EDX) to provide semi-quantitative elemental composition/maps with sub-nanometer resolution. All of these techniques can also be performed in-situ, e.g. during heating, electrical biasing or straining to directly correlate structural changes and materials properties. Furthermore, for complex three-dimensional structures, electron tomography can be used to generate a 3D representation of the material with a spatial resolution of 1–2 nm.

 

FEI Titan 80-300 Transmission Electron Microscope

  • FEG
  • Image aberration corrector
  • Gatan Ultrascan US1000 CCD camera
  • HAADF-STEM detector
  • Gatan GIF 863
  • EDAX S-UTW EDX detector
  • Resolution: 0.08 nm information limit TEM, 0.14 nm resolution in STEM, 0.7 eV energy resolution EELS
  • Imaging and Analysis Techniques: BF-TEM, aber. cor. HRTEM, HAADF-STEM, HRSTEM, EFTEM, EELS, EDX, (S)TEM tomography, Electron diffraction, Lorentz imaging, Low-dose techniques & cryo imaging

 

FEI Titan 80-300 Transmission Electron Microscope

  • FEG
  • Gatan Orion CCD camera
  • HAADF-STEM detector
  • Gatan GIF2001
  • EDAX S-UTW EDX detector
  • NanoMegas ASTAR System with TopSpin
  • Resolution: 0.15 nm information limit TEM, 0.19 nm resolution in STEM, 0.7 eV energy resolution EELS,
  • Imaging and Analysis Techniques: BF-TEM, aber. cor. HRTEM, HAADF-STEM, HRSTEM, EFTEM, EELS, EDX, (S)TEM tomography, (Precession) Electron diffraction, Low-dose techniques & cryo imaging, Orientation mapping

 

TEM holders for both TEMs

  • Analytical single-tilt holder
  • Analytical double-tilt holder
  • Tomography holder – Fischione 2020
  • Double-tilt heating holders: Protochips Aduro 300: RT-1200ºC (MEMS based), Gatan 652: RT-800ºC (classical holder)
  • Cryo-holder: Gatan 915: LN2-80ºC
  • Straining holders: Hysitron Picoindenter PI95 with nanoindentation and straining with PTP, Gatan 654 heating straining holder
  • Electrical Biasing – Protochips Aduro 300
  • Electro chemistry – Protochips Poseidon 510

 

Focused Ion Beam (FIB) Systems

The FEI Strata 400S and the Zeiss Auriga 60 Dual Beam FIB are both a combination of a scanning electron microscope (SEM) and a focused ion beam (FIB) system, which allows imaging and structuring of materials at the nanoscale. The focused gallium ion beam can either be used for ion imaging or to cut predefined patterns or images in the surface of a solid. At the same time, the SEM can be used to image the nanostructures generated by FIB. In addition, it is possible to locally deposit C, Pt or W from precursor gases using the electron or ion beam. Using this combined approach it is possible to

  • perform cross-sectional structural analysis of surfaces
  • extend the cross-sectional analysis by slice and view techniques to image a complete 3D volume
  • pattern surface at the nanoscale
  • electrically contact selected structures on a sample
  • target preparation of TEM samples and in-situ lift-out

 

Zeiss Auriga 60 FIB

  • Electron Optics: 1.0 nm resolution at 15 kV, 1.9 nm resolution at 1 kV, Operation voltage: 200V -30kV
  • Gallium Ion optics: 2.5 nm resolution at 30kV, Operation voltage: 200V – 30kV
  • FEG electron source
  • In-lens SE, ETD, EsB, 4QBSD, SESI detectors for SEM imaging
  • STEM detector
  • EDAX EBSD+EDX detector
  • Omniprobe 400
  • GIS for C, Pt, W, Si
  • Gas injection charge compensation

 

FEI Strata 400 S DualBeam FIB

  • Electron Optics: 1.0 nm resolution at 15 kV, 1.9 nm resolution at 1 kV, Operation voltage: 200V -30kV
  • Gallium Ion optics: 7 nm resolution at 30kV, Operation voltage: 2-30kV
  • FEG electron source
  • TLD SE, ETD, BSE, CDEM detectors for SEM imaging
  • STEM detector
  • EDAX EDX detector
  • Omniprobe 100
  • GIS for C, Pt, and W
  • GIS for XeF2 etch enhance
  • Flip-stage

 

  • Sample Preparation
  • Fischinione NanoMill 1040 for site selected low-voltage argon ion thinning of TEM samples
  • Gatan 691 Procission Ion Polishing Systems equipped with low-voltage option and optional cryo cooling
  • Struers TenuPol-5 electropolishing system
  • Cressington 328 high-vacuum carbon/metal sputter coater, Cressington 108 carbon coater
  • Fischione 1020 Plasma Cleaner
  • MBRAUN glovebox with homebuild SmarAct micromanipulator system
  • Various optiocal microscopes (Leica AxioTech, Leica S6E, Leica M80, Keyence VHX-500)
  • Bulk sample preparation (Sommer GS-1000 wire saw, Gatan 656 dimple grinder, Gatan 623 disc grinder, Struers RotoPol-21 polisher, Struers RotoPol-25 polisher, Struers LaboPress-1 infiltration system)

(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.

EU-Project: Hi-C

„Novel in situ and in operando techniques for characterization of interfaces in electrochemical storage systems“. The objective of the project is to develop methodologies for determining in detail the role of interface boundaries and interface layers on transport properties and reactivity in lithium batteries, and to use the knowledge gained to improve performance.

Das Projekt Hi-C

 

Karlsruhe Nano Micro Facility (KNMF)

The Karlsruhe Nano Micro Facility (KNMF) is a Helmholtz user facility operated at the KIT in Karslruhe providing access to a varierty of nano- and micro structuring and characteriaztion facilities.

Further Information

A specific filter for this group’s publications is not yet available. Please take a look at „publications“ in the website’s header for now.

Mitglieder
Prof. Dr. Christian KübelPrincipal InvestigatorTel: +49 (0721) 608 28970Mail: christian.kuebel(at)kit.edu
ForschungsgruppeResearch Group Prof. Christian Kübel
Dr. Georgian MelinteScientist Tel: +49 (0721) 608 26531Mail: Georgian.Melinte(at)kit.edu
ForschungsgruppeResearch Group Prof. Christian Kübel
Charlotte NeidigerPhD StudentTel: +49 (0721) 608 28925Mail: charlotte.neidiger(at)kit.edu
ForschungsgruppeResearch Group Prof. Christian Kübel
ForschungsgruppeResearch Group Prof. Christian Kübel
Forschung

(images will be uploaded shortly)

 

Electron Microscopic Characterization of Batteries and Materials

The development of advanced materials for new batteries increasingly focuses on nanostructured composites to combine high electron and ion conductivity for new cathode materials. These nano composites typically exhibit a complex morphology geared to maintain high capacity over extended charging/discharging cycles. The aim of the electron microscopy & spectroscopy group is to characterize the morphology and composition of the active battery materials at the atomic to nanometer scale in 2D and also 3D using a combination of high-resolution imaging (TEM, HAADF-STEM), spectroscopy (EELS, EDX) and tomographic techniques to correlate the structure and morphology at different charging states with the cyclic stability. To some extent, this characterization is possible using well-developed ex-situ analytical (S)TEM techniques that only need to be optimized to deal with the electron beam sensitivity of most battery materials. However,for a more direct analysis of the structural changes during electrochemical cycling, we are also actively developing new techniques for in-situ imaging of micron/nano-sized battery models inside the TEM.

 

Metal fluorides as conversion electrodes in lithium ion batteries

In collaboration with Prof. Max Fichtner, we have characterized the structure of Fe/Lif/C conversion electrodes used as cathode materials in lithium-ion batteries. The conversion materials prepared pyrolysis of ferrocene with LiF initially consist of iron (and some iron carbide) nanoparticles with a thin graphitic shell, interconnected by MWCNTs.

Charging leads to the formation of FeF2/C or FeF3/C nanoparticles with the graphitic shell still present.
Both, the graphitic shell and the MWCNTs are crucial for a good cyclic behavior with the graphitic shell presumably responsible forthe cyclicstability of the iron nanoparticles and the MWCNTs ensuring electrical contact through the electrode.

 

Development of in-situ TEM characterization of the cyclic behaviour of solid state batteries

In addition to the ex-situ analysis shown above, we are developing new preparation and analysis approaches to follow the structural changes in micron sized solid state batteries and half cells in-situ using TEM techniques. The basic idea is to use FIB preparation to cut a thin cross-section from a solid state battery that is then transferred under (close to) inert conditions onto an electro-contacting TEM holder for in-situ analysis using low-dose and low voltage TEM and STEM techniques.

The materials currently under investigation are solid state lithium ion batteries with Garnet type electrolytes in collaboration with Prof. Jürgen Janek group at the University Giessen  and new lithium-free fluoride based solid state batteries in collaboration with Prof. Max Fichtner.

 

In-situ liquid in the TEM

As part of the development of the in-situ liquid experiments in the TEM, we have the possibility to introduce liquids between two SiN membranes using a Protochips Posseidon in-situ liquid flow holder along with electrical measurements. On the other hand, nanoparticles can also be generated in liquids inside the TEM induced through electron beam which is critical to differentiate from the actual experiment of interest.

Equipment

(information will be uploaded shortly)

 

The electron microscopy and spectroscopy group is operating the following equipment at the Institute of Nanotechnology (INT) in Karlsruhe, which is available for research activities within HIU:

Laboratories

  • SEM, FIB and TEM laboratories
  • Metallography laboratory for SEM/TEM sample preparation
  • Sample preparation laboratory for battery materials with MBRAUN glovebox equipped with micromanipulator controlled sample handling
  • Image processing laboratory with specialized software for SEM and TEM image analysis and processing

Equipment

 

Transmission Electron Microscopes (TEM)

 

Transmission electron microscopy (TEM) enables characterization of materials by direct imaging with up to atomic resolution. The image information can be locally correlated with spectroscopic techniques (EELS/EFTEM and EDX) to provide semi-quantitative elemental composition/maps with sub-nanometer resolution. All of these techniques can also be performed in-situ, e.g. during heating, electrical biasing or straining to directly correlate structural changes and materials properties. Furthermore, for complex three-dimensional structures, electron tomography can be used to generate a 3D representation of the material with a spatial resolution of 1–2 nm.

 

FEI Titan 80-300 Transmission Electron Microscope

  • FEG
  • Image aberration corrector
  • Gatan Ultrascan US1000 CCD camera
  • HAADF-STEM detector
  • Gatan GIF 863
  • EDAX S-UTW EDX detector
  • Resolution: 0.08 nm information limit TEM, 0.14 nm resolution in STEM, 0.7 eV energy resolution EELS
  • Imaging and Analysis Techniques: BF-TEM, aber. cor. HRTEM, HAADF-STEM, HRSTEM, EFTEM, EELS, EDX, (S)TEM tomography, Electron diffraction, Lorentz imaging, Low-dose techniques & cryo imaging

 

FEI Titan 80-300 Transmission Electron Microscope

  • FEG
  • Gatan Orion CCD camera
  • HAADF-STEM detector
  • Gatan GIF2001
  • EDAX S-UTW EDX detector
  • NanoMegas ASTAR System with TopSpin
  • Resolution: 0.15 nm information limit TEM, 0.19 nm resolution in STEM, 0.7 eV energy resolution EELS,
  • Imaging and Analysis Techniques: BF-TEM, aber. cor. HRTEM, HAADF-STEM, HRSTEM, EFTEM, EELS, EDX, (S)TEM tomography, (Precession) Electron diffraction, Low-dose techniques & cryo imaging, Orientation mapping

 

TEM holders for both TEMs

  • Analytical single-tilt holder
  • Analytical double-tilt holder
  • Tomography holder – Fischione 2020
  • Double-tilt heating holders: Protochips Aduro 300: RT-1200ºC (MEMS based), Gatan 652: RT-800ºC (classical holder)
  • Cryo-holder: Gatan 915: LN2-80ºC
  • Straining holders: Hysitron Picoindenter PI95 with nanoindentation and straining with PTP, Gatan 654 heating straining holder
  • Electrical Biasing – Protochips Aduro 300
  • Electro chemistry – Protochips Poseidon 510

 

Focused Ion Beam (FIB) Systems

The FEI Strata 400S and the Zeiss Auriga 60 Dual Beam FIB are both a combination of a scanning electron microscope (SEM) and a focused ion beam (FIB) system, which allows imaging and structuring of materials at the nanoscale. The focused gallium ion beam can either be used for ion imaging or to cut predefined patterns or images in the surface of a solid. At the same time, the SEM can be used to image the nanostructures generated by FIB. In addition, it is possible to locally deposit C, Pt or W from precursor gases using the electron or ion beam. Using this combined approach it is possible to

  • perform cross-sectional structural analysis of surfaces
  • extend the cross-sectional analysis by slice and view techniques to image a complete 3D volume
  • pattern surface at the nanoscale
  • electrically contact selected structures on a sample
  • target preparation of TEM samples and in-situ lift-out

 

Zeiss Auriga 60 FIB

  • Electron Optics: 1.0 nm resolution at 15 kV, 1.9 nm resolution at 1 kV, Operation voltage: 200V -30kV
  • Gallium Ion optics: 2.5 nm resolution at 30kV, Operation voltage: 200V – 30kV
  • FEG electron source
  • In-lens SE, ETD, EsB, 4QBSD, SESI detectors for SEM imaging
  • STEM detector
  • EDAX EBSD+EDX detector
  • Omniprobe 400
  • GIS for C, Pt, W, Si
  • Gas injection charge compensation

 

FEI Strata 400 S DualBeam FIB

  • Electron Optics: 1.0 nm resolution at 15 kV, 1.9 nm resolution at 1 kV, Operation voltage: 200V -30kV
  • Gallium Ion optics: 7 nm resolution at 30kV, Operation voltage: 2-30kV
  • FEG electron source
  • TLD SE, ETD, BSE, CDEM detectors for SEM imaging
  • STEM detector
  • EDAX EDX detector
  • Omniprobe 100
  • GIS for C, Pt, and W
  • GIS for XeF2 etch enhance
  • Flip-stage

 

  • Sample Preparation
  • Fischinione NanoMill 1040 for site selected low-voltage argon ion thinning of TEM samples
  • Gatan 691 Procission Ion Polishing Systems equipped with low-voltage option and optional cryo cooling
  • Struers TenuPol-5 electropolishing system
  • Cressington 328 high-vacuum carbon/metal sputter coater, Cressington 108 carbon coater
  • Fischione 1020 Plasma Cleaner
  • MBRAUN glovebox with homebuild SmarAct micromanipulator system
  • Various optiocal microscopes (Leica AxioTech, Leica S6E, Leica M80, Keyence VHX-500)
  • Bulk sample preparation (Sommer GS-1000 wire saw, Gatan 656 dimple grinder, Gatan 623 disc grinder, Struers RotoPol-21 polisher, Struers RotoPol-25 polisher, Struers LaboPress-1 infiltration system)
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.

EU-Project: Hi-C

„Novel in situ and in operando techniques for characterization of interfaces in electrochemical storage systems“. The objective of the project is to develop methodologies for determining in detail the role of interface boundaries and interface layers on transport properties and reactivity in lithium batteries, and to use the knowledge gained to improve performance.

Das Projekt Hi-C

 

Karlsruhe Nano Micro Facility (KNMF)

The Karlsruhe Nano Micro Facility (KNMF) is a Helmholtz user facility operated at the KIT in Karslruhe providing access to a varierty of nano- and micro structuring and characteriaztion facilities.

Further Information

Publikationen

A specific filter for this group’s publications is not yet available. Please take a look at „publications“ in the website’s header for now.

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