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Suche nach „[S: TC Plattling MoMo]“ hat 108 Publikationen gefunden
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    MobilNachhaltigS: TC Plattling MoMo

    Zeitschriftenartikel

    H. Bülter, Michael Sternad, E. dos Santos Sardinha, J. Witt, C. Dosche, M. Wilkening, G. Wittstock

    Investigation of the Electron Transfer at Si Electrodes: Impact and Removal of the Native SiO 2 Layer

    Journal of The Electrochemical Society, vol. 163, no. 3

    2016

    DOI: 10.1149/2.0731603jes

    Abstract anzeigen

    Silicon is considered as one of the promising alternatives to graphite as negative electrode material in lithium-ion batteries. The electron transfer at uncharged microstructured and planar Si was characterized using the feedback mode of scanning electrochemical microscopy (SECM) and 2,5-di-tert-butyl-1,4-dimethoxybenzene as redox mediator. Approach curves and images demonstrate that the electron transfer rate constants at pristine Si are relatively small due to the native SiO2 surface layer. In addition, the electron transfer rate constants show local variations because of the heterogeneous coverage of SiO2. The SiO2 layer is at least partially removed by mechanical contact and abrasion with the microelectrode probe. After SiO2 removal by the microelectrode or by a hydrofluoric acid dip, the electron transfer rate constants increase strongly and remain heterogeneous. Moreover, the surface of the Si electrodes is at least stable over hours after SiO2 removal. The consequences for investigating the formation of the solid electrolyte interphase (SEI) on Si are discussed.

    DigitalF: Angewandte InformatikS: TC Plattling MoMo

    Zeitschriftenartikel

    T. Hammer, Berthold Bäuml

    The Communication Layer of the aRDx Software Framework: Highly Performant and Realtime Deterministic

    Journal of Intelligent & Robotic Systems, vol. 77, pp. 171-185

    2015

    DOI: 10.1007/s10846-014-0095-9

    Abstract anzeigen

    Communication between software components is one of the most important functionalities a software framework for modern complex robotic systems has to provide. Here, we present the highly performant realtime communication layer of our new robotic software framework aRDx (agile robot development – next generation), with, e.g., zero-copy semantics, realtime determinism and detailed control of the QoS (quality of service). In addition, we give an in- depth performance comparison to other popular robotic frameworks, namely ROS, YARP, Orocos and aRD.

    DigitalF: Angewandte InformatikS: TC Plattling MoMo

    Zeitschriftenartikel

    O. Birbach, U. Frese, Berthold Bäuml

    Rapid calibration of a multi-sensorial humanoid’s upper body: An automatic and self-contained approach

    The International Journal of Robotics Research, vol. 34, no. 4-5, pp. 420-436

    2015

    DOI: 10.1177/0278364914548201

    Abstract anzeigen

    This paper addresses the problem of calibrating a pair of cameras, a Microsoft Kinect sensor and an inertial measurement unit (IMU) mounted at the head of a humanoid robot with respect to its kinematic chain. As complex manipulation tasks require an accurate interplay of all involved sensors, the quality of calibration is crucial for the outcome of the intended tasks. Typical procedures for calibrating are often time-consuming, involve multiple people overseeing a series of subsequent calibration steps and require external tools. We therefore propose to auto-calibrate all sensors in a single, completely automatic and self-contained procedure, i.e. without a calibration plate. By automatically detecting a single point feature on each wrist while moving the robot’s head, the stereo cameras’, the Kinect’s infrared camera’s intrinsic and extrinsic and an IMU’s extrinsic parameters are calibrated while considering the arm joint elasticities and joint angle offsets. All parameters are obtained by formulating the calibration problem as a single least-squares batch-optimization problem. The procedure is integrated on DLR’s humanoid robot Agile Justin allowing to obtain an accurate calibration in around 5 minutes by simply “pushing a button”. The proposed approach is experimentally validated by means of standard metrics of the calibration errors.

    MobilNachhaltigS: TC 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

    MobilNachhaltigS: TC Plattling MoMo

    Patent

    Michael Sternad, K. Rowold

    Zelle eines Energiespeichers für ein Fahrzeug

    2015

    MobilNachhaltigS: TC 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

    MobilNachhaltigS: TC 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.

    MobilNachhaltigS: TC 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.

    MobilNachhaltigS: TC 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.

    MobilNachhaltigS: TC 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

    MobilNachhaltigS: TC 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

    MobilNachhaltigS: TC 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 (The Electrochemical Society), 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.

    MobilNachhaltigS: TC 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

    MobilNachhaltigS: TC Plattling MoMo

    Patent

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

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

    2014

    MobilNachhaltigS: TC Plattling MoMo

    Patent

    Michael Sternad, J. Hirschler, M. Forster, M. Sorger, K. Schmut, B. Goller, et al.

    BATTERY ELECTRODE, BATTERY, AND METHOD FOR MANUFACTURING A BATTERY ELECTRODE.

    2014

    MobilNachhaltigS: TC 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

    2014

    MobilNachhaltigS: TC 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

    2014

    MobilNachhaltigS: TC Plattling MoMo

    Zeitschriftenartikel

    R. Janski, M. Fugger, Michael Sternad, M. Wilkening

    Lithium Distribution in Monocrystalline Silicon-Based Lithium-Ion Batteries

    ECS Transactions (The Electrochemical Society), vol. 62, no. 1, pp. 247-253

    2014

    DOI: 10.1149/06201.0247ecst

    Abstract anzeigen

    The ability of nitrides and alloys of refractory metals to act as solid-state diffusion barrier for Li migration in Si was evaluated by mass spectrometry techniques. Magnetron sputtered barrier films on silicon, assembled in a Swagelok® half-cell, were used as working electrodes to determine whether several barrier layers are able to prevent the formation of Li-Si alloys. In addition, lithium ion diffusion was studied in monocrystalline silicon. To determine the depth profiles in the silicon substrate and in the barrier layer, respectively, two complementary techniques, being based on mass spectrometry, were applied: (i) ToF-SIMS was used as imaging technique for depth profiling the first microns and (ii) laser ablation ICP-MS was carried out to study depth profiles of up to hundreds of microns. Titanium nitride as well as tantalum nitride barriers turned out to prevent or inhibit the reaction between lithium and silicon. Regarding Li diffusion in silicon preliminary tests were performed to investigate both diffusion coefficients and the activation energies in (100) monocrystalline silicon.

    MobilNachhaltigS: TC Plattling MoMo

    Vortrag

    R. Janski, M. Fugger, Michael Sternad, M. Wilkening

    Lithium Distribution in Monocrystalline Silicon based Lithium-Ion Batteries

    Poster presentation

    17th International Meeting on Lithium Batteries, Como, Italien

    2014

    MobilNachhaltigS: TC Plattling MoMo

    Patent

    J. Hirschler, M. Forster, M. Sorger, K. Schmut, B. Goller, P. Schweizer, et al.

    BATTERY ELECTRODE, BATTERY, AND METHOD FOR MANUFACTURING A BATTERY ELECTRODE

    2014