Suche nach „[2015]“ hat 246 Publikationen gefunden

DigitalDEG-DLM1IQW

Buch (Monographie)

Anja Coenen, Karina Fisch, Andreas Oswald, Martina Reitmaier-Krebs, Ilona Seifert

Ist- und Bedarfsanalyse im Rahmen des Projekts DEG-DLM

2015

DigitalDEG-DLM1IQW

Buch (Monographie)

Karina Fisch, Martina Reitmaier-Krebs

Bedarf an didaktischer Gestaltung von Lernprozessen in berufsbegleitenden Weiterbildungen

2015

MobilAngewandte InformatikTC Grafenau

Vortrag

Christian Kluge

Optimierung der Reichweitenschätzung für Elektrofahrzeuge im Verbundprojekt E-WALD

E-WALD Projekttag, Teisnach

2015

MobilNachhaltigTC Plattling MoMo

Vortrag

A. Dunst, Michael Sternad, V. Epp, M. Wilkening

Fast Li Self-Diffusion in Amorphous Li-Si Electrochemically Prepared from Semiconductor Grade, Monocrystalline Silicon — Insights from Spin-Locking Nuclear Magnetic Relaxometry

Poster presentation

20th International Conference on Solid State Ionics, Keystone, CO, USA

2015

MobilNachhaltigTC Plattling MoMo

Patent

Michael Sternad, K. Rowold

Zelle eines Energiespeichers für ein Fahrzeug

2015

MobilNachhaltigTC Plattling MoMo

Patent

Michael Sternad, M. Forster, K. Schmut, B. Goller, Zieger G., M. Sorger, et al.

LITHIUM BATTERY, METHOD FOR MANUFACTURING A LITHIUM BATTERY, INTEGRATED CIRCUIT AND METHOD OF MANUFACTURING AN INTEGRATED CIRCUIT

2015

MobilNachhaltigTC Plattling MoMo

Zeitschriftenartikel

W. Schmidt, P. Bottke, Michael Sternad, P. Gollob, V. Hennige, M. Wilkening

Small Change—Great Effect: Steep Increase of Li Ion Dynamics in Li 4 Ti 5 O 12 at the Early Stages of Chemical Li Insertion

Chemistry of Materials, vol. 27, no. 5, pp. 1740-1750

2015

DOI: 10.1021/cm504564k

Abstract anzeigen

Lithium titanate (LTO) is one of the most promising anode materials for large-scale stationary electrochemical storage of energy produced from renewable sources. Besides many other aspects, such as negligible formation of passivation layers and no volume expansion during lithiation, the success of LTO is mainly based on its ability to easily accommodate and release Li ions in a fully reversible way. This feature is tightly connected with Li self-diffusion. As yet, little information is available about microscopic Li diffusion properties and elementary steps of Li hopping at low intercalation levels, i.e., at values of x being significantly smaller than 1. Here, we used 7Li spin-locking NMR relaxometry to probe absolute hopping rates of LTO (homogeneous) solid solutions in quasi-thermodynamic equilibrium. As a result, the largest increase of Li diffusivity is observed when small amounts of Li are inserted. Strong Coulomb repulsions caused by the simultaneous occupation of neighboring 8a and 16c sites serve as an explanation for the enhanced Li diffusivity found. At even larger values of x, Li mobility slows down but is still much faster than in the host material with x = 0. Our results experimentally corroborate the outcome of recently published calculations on the DFT level focusing on both dynamic and structural aspects. The findings favor the formation of LTO solid solutions upon chemical lithiation; the steep increase in Li diffusivity found might also help with understanding the flat insertion potential observed.

MobilNachhaltigTC Plattling MoMo

Zeitschriftenartikel

J. Langer, V. Epp, Michael Sternad, M. Wilkening

Diffusion-induced 7Li NMR relaxation of layer-structured tin disulphide — Li diffusion along the buried interfaces in Li0.17SnS2

Solid State Ionics, vol. 276, no. August, pp. 56-61

2015

DOI: 10.1016/j.ssi.2015.03.039

Abstract anzeigen

7Li NMR relaxation has been used to study lithium-ion diffusion in layer-structured SnS2. Keeping the Li intercalation degree in LixSnS2 below x = 0.49, the Li ions preferentially occupy sites in the van der Waals gap between the SnS2 sheets. In contrast to conventional NMR spin-lattice relaxation (SLR) rate measurements in the laboratory frame of reference, which are sensitive to rather fast Li exchange processes, with the help of spin-locking SLR NMR slower Li motions were extracted from characteristic diffusion-induced rate peaks. The latter contain information on both Li+ activation energies Ea and Li ion jump rates τ− 1 characterizing the elementary steps of Li+ hopping. Our results point to two different diffusion processes (Ea(I) = 0.38 eV; Ea(II) = 0.28 eV), a slower and a faster one, observable directly after chemical Li insertion. Interestingly, the diffusion behaviour irreversibly changes when the sample has been exposed to temperatures as high as 573 K. Diffusion-induced NMR rates and corresponding line shapes are discussed with respect to an inhomogenous distribution of Li ions in SnS2, which seems to be present directly after Li intercalation.

MobilNachhaltigTC Plattling MoMo

Zeitschriftenartikel

A. Dunst, Michael Sternad, V. Epp, M. Wilkening

Fast Li+ Self-Diffusion in Amorphous Li–Si Electrochemically Prepared from Semiconductor Grade, Monocrystalline Silicon: Insights from Spin-Locking Nuclear Magnetic Relaxometry

The Journal of Physical Chemistry C, vol. 119, no. 22, pp. 12183-12192

2015

DOI: 10.1021/acs.jpcc.5b02490

Abstract anzeigen

Silicon is one of the most promising anode materials for lithium-based rechargeable batteries. Provided the volume changes during Li uptake can be brought under control, Li ion diffusivity is expected to crucially determine the performance of such next-generation energy storage systems. Therefore, studying diffusion properties in e.g. amorphous Li–Si underpins applied research that is being directed toward the development of powerful storage devices. So far, only little information is available on Li+ self-diffusion in amorphous Si. Here, we used 7Li NMR spectroscopy to precisely quantify microscopic activation energies and Li jump rates in amorphous Li–Si which is primarily formed if monocrystalline Si is lithiated electrochemically. Surprisingly, our results reveal relatively fast Li ion diffusivity with low activation energies for localized Li+ motions being in agreement with results from theory. The average activation energy for long-range ion transport is as high as ca. 0.65 eV; jump rates turn out to be in the order of 2.5 × 105 s–1 at 246 K. Our results point to complex dynamics that is most likely governed by nonexponential motional correlation functions originating from a distribution of activation energies. The data obtained might help optimizing Li-based silicon batteries whose performance critically depend on fast Li ion transport.

MobilNachhaltigTC Plattling MoMo

Vortrag

A. Dunst, Michael Sternad, V. Epp, M. Wilkening

Lithium ion dynamics in amorphous Li-Si electrochemically prepared from semiconductor grade, monocrystalline silicon — An NMR Study

Poster presentation

Materials Day 2015, Graz, Österreich

2015

MobilNachhaltigTC Plattling MoMo

Vortrag

A. Dunst, Michael Sternad, V. Epp, M. Wilkening

Fast Li self-diffusion in Li-Si Electrochemically Prepared from Semiconductor Grade, Monocrystalline Silicon

15th European Conference on Solid State Chemistry (ECSSC), Wien, Österreich

2015

MobilNachhaltigTC Plattling MoMo

Zeitschriftenartikel

H. Bülter, Michael Sternad, M. Wilkening, G. Wittstock

Impact of the Native SiO2 Surface Layer on the Electron Transfer at Amorphous Si Electrodes

ECS Transactions, vol. 68, no. 2, pp. 1-11

2015

DOI: 10.1149/06802.0001ecst

Abstract anzeigen

The electron transfer at uncharged microstructured and planar amorphous (a-)Si was characterized using the feedback mode of scanning electrochemical microscopy (SECM) and 2,5-di-tert-butyl-1,4-dimethoxybenzene as redox mediator in carbonate electrolytes. Approach curves and images demonstrate that the electron transfer rate at pristine a-Si is relatively small due to the native SiO2 surface layer. In addition, the electron transfer rates show local variations because of the heterogeneous coverage of SiO2. After removal of the SiO2 layer, the effect of the solid electrolyte interphase (SEI) on electron transport rate can be studied. The SiO2 layer is at least partially removed by approach curve contact and scratching with the microelectrode probe. After SiO2 removal, the electron transfer rates increase strongly and remain heterogeneous.

MobilNachhaltigTC Plattling MoMo

Vortrag

H. Bülter, Michael Sternad, M. Wilkening, G. Wittstock

Comparison of Spatiotemperoal Changes of SEI Properies on Different Anodes by SECM

ECS Conference on Electrochemical Energy Conversion & Storage with SOFC-XIV, Glasgow, United Kingdom

2015

GesundAngewandte Gesundheitswissenschaften

Vortrag

Richard Latzel, S. Kaufmann, Stier S., V. Fresz, D. Reim, R. Beneke, O. Hoos

Physiologische Beanspruchung deutscher Nachwuchsleistungsbasketballer beim Basketball Exercise Simulation Test (BEST)

22. Sportwissenschaftlicher Hochschultag der Deutschen Vereinigung für Sportwissenschaft (dvs), Mainz

2015

GesundAngewandte Gesundheitswissenschaften

Vortrag

Richard Latzel

Schüler- und Lehrergesundheit: Möglichkeiten zur Verbesserung der physischen und psychischen Gesundheit von Schülern und Lehrern durch Bewegung

Vortrag und Workshop

2015

NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenTC Teisnach Sensorik

Zeitschriftenartikel

J. Landskron, K. Schmidt, Maria Kufner, G. Lindner

Stable vortex generation in liquid filled wells by mode conversion of surface acoustic waves

Physics Procedia, vol. 70, no. Proceedings of the 2015 ICU International Congress on Ultrasonics, Metz, France, pp. 98-101

2015

DOI: 10.1016/j.phpro.2015.08.051

Abstract anzeigen

The formation of stable vortex flow pattern has been observed at liquid filled aluminum wells of 15 to 30 mm diameter when Lamb waves are excited on the bottom of the wells by piezoelectric transducers operated at a frequency of 1 MHz. The shape of the vortex pattern changed with the position of the transducer. Strong differences in mixing times were observed between water and ethanol when the filling level was changed and a remarkable reduction of mixing time was achieved by the addition of a small amount of detergent to water at small filling levels. Besides mixing of liquids thermal equilibration within a liquid volume was accelerated by acoustic streaming.

NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenTC Weißenburg

Patent

Gerhard, R., Dmitry Rychkov, Wirges, W., et al.

Electromechanical transducer device for use in e.g. actuator device, has electret material having predetermined electrical charge, which is provided between electro-active layers

2015

TC Cham

Patent

Frank Denk, Continental Automotive GmbH

[DE] Ermittlung des Zeitpunkts eines vorbestimmten Öffnungszustandes eines Kraftstoffinjektors [EN] Determination of the point in time of a predetermined open state of a fuel injector [FR] Détermination ...

2015

TC Cham

Patent

Frank Denk, Continental Automotive GmbH

Verfahren und Vorrichtung zur Bestimmung des Öffnungsverhaltens eines Kraftstoffinjektors für eine Brennkraftmaschine

2015

TC Cham

Patent

Frank Denk, G. Rösel, Continental Automotive GmbH

Determining the movement behaviour over time of a fuel injector on the basis of an evaluation of the temporal progression of various electrical measurement variables

2015