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Prof. DI Dr.techn. Michael Sternad

Chemie und Technologie elektrochemischer Energiespeicher

Zentrum für angewandte Forschung

Technologie Campus Plattling MoMo

Wissenschaftliche Leitung

Wissenschaftlicher Leiter | Forschungszentrum Moderne Mobilität

R 112

0991/3615-324

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Publikationen

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Hochschulschrift

Michael Sternad

Entwicklung von Hochtemperaturelektrolyten für Lithium-Ionen-Batterien.

Technische Universität Graz, Graz, Österreich.

(2005)

Vortrag

N. Hochgatterer
E. Lanzer
P. Raimann
K.-C. Möller
M. Winter
Michael Sternad
et al.

Monitoring electrode reactions by in situ ESEM. Poster presentation.

Biarritz, Frankreich 2006.

(2006)

Vortrag

C. Korepp
K.-C. Möller
E. Lanzer
Michael Sternad
P. Raimann
M. Schweiger
et al.

Isocyanate Compounds as Electrolyte Additives for Lithium-Ion Batteries. Poster presentation.

Biarritz, Frankreich 2006.

(2006)

Vortrag

J. Besenhard
K. Leitner
A. Basch
A. Hosseinmardi
Michael Sternad
P. Raimann

Thin Layer Electrodes and Improved Percolation Pattern Composites Prepared by Atmospheric Pressure Ion Deposition and Substrate Induced Coagulation.

Beijing Exhibition Center, Peking, China 2006.

(2006)

Vortrag

E. Lanzer
P. Raimann
K.-C. Möller
Michael Sternad
N. Hochgatterer
M. Schweiger
et al.

On the origin of gases evolved during electrolyte decomposition at silicon anodes in Lithium-Ion batteries. Poster presentation.

Biarritz, Frankreich 2006.

(2006)

Vortrag

Michael Sternad
C. Korepp
E. Lanzer
P. Raimann
M. Schweiger
N. Hochgatterer
et al.

Ethyl isocyanate - An electrolyte additive for PC based electrolytes in lithium ion batteries.. Poster presentation.

Biarritz, Frankreich 2006.

(2006)

Vortrag

P. Raimann
J. Besenhard
K.-C. Möller
M. Winter
Michael Sternad
N. Hochgatterer
et al.

Preparation of Thin Film Model Electrodes by APID (Atmospheric Pressure Ion Deposition. Poster presentation.

Cancun, Mexiko 2006.

(2006)

Vortrag

M. Winter
C. Korepp
P. Raimann
N. Hochgatterer
M. Schweiger
Michael Sternad
K.-C. Möller
J. Besenhard

PC for PCs? Chances and Limitations of Propylene Carbonate Based Lithium Ion Cells.

Cancun, Mexiko 2006.

(2006)

Vortrag

P. Raimann
E. Lanzer
K.-C. Möller
M. Winter
Michael Sternad
N. Hochgatterer
et al.

Advanced electrochemical mass spectrometry. Poster presentation.

Biarritz, Frankreich 2006.

(2006)

Vortrag

S. Koller
H. Kren
M. Winter
N. Hochgatterer
M. Schweiger
M. Schmuck
A. Balducci
C. God
C. Bayer
B. Fuchsbichler
Michael Sternad
C. Stangl

Comprehension and tailoring of cellulose based binders as fundament for applicable silicon/graphite composite anodes.

Shenzhen, China 2007.

(2007)

Vortrag

M. Schweiger
N. Hochgatterer
P. Raimann
Michael Sternad
M. Winter

Electrolyte Decomposition On Chemically And Electrochemically Formed Li-Intermetallics. Poster presentation.

Banff, Canada 2007.

(2007)

Vortrag

M. Schweiger
N. Hochgatterer
P. Raimann
Michael Sternad
M. Schmuck
A. Balducci
et al.

"Mono --> Poly": Polymerization reactions in lithium batteries.

Rome, Italy 2007.

(2007)

Vortrag

N. Hochgatterer
S. Koller
M. Schweiger
P. Raimann
M. Schmuck
Michael Sternad
et al.

From graphite to lithium storage alloy anodes chances limitations.

Kyushu, Japan 2007.

(2007)

Vortrag

Michael Sternad
E. Lanzer
N. Hochgatterer
S. Koller
P. Raimann
M. Schmuck
et al.

Temperature Controlled Pressure Characterization (TPC) of Lithium-Ion Batteries with Silicon based Anodes.

Washington, D.C., USA 2007.

(2007)

Vortrag

N. Hochgatterer
P. Raimann
M. Schweiger
Michael Sternad
M. Winter

Deckschichtbildung auf Anoden in wiederaufladbaren Lithiumbatterien.

Graz, Österreich 2007.

(2007)

Vortrag

N. Hochgatterer
P. Raimann
M. Schweiger
Michael Sternad
M. Winter

Development of nanostructrured Sn/SnSb/Cu composite anode and their characterization via ESEM. Poster presentation.

Banff, Canada 2007.

(2007)

Vortrag

M. Schweiger
N. Hochgatterer
S. Koller
P. Raimann
Michael Sternad
M. Schmuck
et al.

Lithium Battery´s meaning of liefe: the Solid Electrolyte Interphase (SEI).

Banff, Kanada 2007.

(2007)

Vortrag

P. Raimann
N. Hochgatterer
M. Schweiger
Michael Sternad
M. Winter

Zukunfts-Management für regionale Betriebe ( Methoden und Werkzeuge - Chancen und Potenziale).

Ökopark Hartberg, Österreich 2007.

(2007)

Hochschulschrift

Michael Sternad

Silicon Insertion Electrodes for Lithium-Ion Batteries.

Technische Universität Graz, Graz, Österreich. Institut für Chemische Technologie von Materialien

(2008)

Vortrag

Michael Sternad
H. Kren
C. Bayer
C. God
S.F. Lux
C. Stangl
et al.

Investigating the SEI-layer on Silicon Insertion Electrodes of Lithium-Ion Batteries by Pyrolysis-GC/MS.

Honolulu, Hawaii, USA 2008.

(2008)

Vortrag

S. Koller
C. God
C. Bayer
B. Fuchsbichler
S.F. Lux
M. Schmuck
Michael Sternad
et al.

SILICON NANO PARTICLES - Both a blessing and curse.

Honolulu, Hawaii, USA 2008.

(2008)

Vortrag

P. Raimann
N. Hochgatterer
M. Schweiger
Michael Sternad
M. Winter

Batterien und Brennstoffzellen für Elektrofahrzeuge.

Hartberg, Österreich 2008.

(2008)

Vortrag

C. Stangl
C. Bayer
C. God
B. Fuchsbichler
S.F. Lux
M. Schmuck
Michael Sternad
et al.

Influence of pressure on the cycling stability of silicon electrodes in lithium-ion batteries. Poster presentation.

Honolulu, Hawaii, USA 2008.

(2008)

Vortrag

S. Koller
B. Fuchsbichler
H. Kren
Michael Sternad
C. Bayer
C. God
et al.

Lithium-Power-Group: Forschungsgebiete. Posterpräsentation.

Graz, Österreich 2008.

(2008)

TC Plattling MoMo

Patentschrift

Michael Sternad
M. Winter
Y. Ohashi
T. Fujii
S. Kinoshita

NONAQUEOUS ELECTROLYTIC SOLUTION FOR SECONDARY BATTERY, AND NONAQUEOUS ELECTROLYTIC SOLUTION SECONDARY BATTERY USING IT.

(2008)

Vortrag

C. God
C. Bayer
B. Fuchsbichler
S. Koller
H. Kren
S.F. Lux
Michael Sternad
et al.

Y-butyrolacton as alternative electrolyte component for high voltage Lithium-Ion Batteries.

Honolulu, Hawaii, USA 2008.

(2008)

Vortrag

M. Winter
M. Schweiger
K. Gschweitl
Michael Sternad

Ist die Lithium-Ionen-Batterie reif für das Elekrofahrzeug? Eine Analyse aus materialwissenschaftlicher Sicht.

Graz, Österreich 2008.

(2008)

Vortrag

S. Koller
B. Fuchsbichler
H. Kren
Michael Sternad
C. Bayer
C. God

Lithium-Ion Batteries.

Graz 2008.

(2008)

Vortrag

B. Fuchsbichler
H. Kren
M. Schmuck
Michael Sternad
C. Bayer
C. God
et al.

Germanium for High Capacity Lithium Ion Battery Anodes. Poster presentation.

Honolulu, Hawaii, USA 2008.

(2008)

Vortrag

G. Brasseur
Michael Sternad
H. Kren

Energy Storage Systems for Hybrid Vehicles, from Racing to Production cars.

Wien, Österreich 2008.

(2008)

Vortrag

S.F. Lux
M. Schmuck
A. Balducci
B. Fuchsbichler
C. Stangl
H. Kren
Michael Sternad
et al.

Different Room Temperature Ionic Liquids and their Mixtures as Electrolytes for Graphite Negative Electrodes in Lithium Ion Batteries. Poster presentation.

Honolulu, Hawaii 2008.

(2008)

Vortrag

S. Koller
B. Fuchsbichler
M. Schmuck
C. Bayer
C. God
S.F. Lux
C. Stangl
H. Kren
Michael Sternad
M. Winter

Functional Binders as Basic Fundament for Applicable Lithium-Alloy Based Anodes in Lithium Ion Batteries.

Brno, Tschechische Republik 2008.

(2008)

Vortrag

B. Fuchsbichler
H. Kren
M. Schmuck
Michael Sternad
C. Bayer
C. God
et al.

Influence of Pressure on the Cycling Stability of Silicon-Electrodes. Poster presentation.

Brno, Tschechische Republik 2008.

(2008)

Vortrag

H. Kren
Michael Sternad
B. Fuchsbichler
S. Koller
M. Schmuck
C. Bayer
et al.

Cathodic decomposition processes on LiFePO4 and LiMn204 electrodes - leading to aging in high power Lithium-Ion Batteries. Poster presentation.

Honolulu, Hawaii, USA 2008.

(2008)

Vortrag

M. Schmuck
B. Fuchsbichler
H. Kren
Michael Sternad
C. Bayer
C. God
et al.

Methoden für die Angewandte Materialcharakterisierung. Posterpräsentation.

Graz, Österreich 2008.

(2008)

Vortrag

C. Bayer
B. Fuchsbichler
S. Koller
H. Kren
M. Schmuck
Michael Sternad
et al.

Propargyl Benzenesulfonate - A Triple-Bonded Electrlyte Additive for Electrolytes in Lithium Ion Batteries. Poster presentation.

Honolulu, Hawaii, USA 2008.

(2008)

Patentschrift

Michael Sternad
M. Winter
Y. Ohashi
T. Fujii
S. Kinoshita

NONAQUEOUS ELECTROLYTIC SOLUTION FOR SECONDARY BATTERY, AND NONAQUEOUS ELECTROLYTIC SOLUTION SECONDARY BATTERY USING IT..

(2009)

Patentschrift

Michael Sternad
M. Winter
P. Raimann

In-situ Druckmessung für elektrochemische Systeme.

(2009)

Vortrag

R. Hohl
H. Kren
B. Fuchsbichler
C. Stangl
C. Bayer
C. God
Michael Sternad
et al.

Differential Scanning Calorimetry and Thermo Gravimetry with In-Situ Online Mass Spectrometry Studies on Lithium Iron Phosphate Cathodes and Carbon Anodes.

Wien, Österreich 2009.

(2009)

Patentschrift

Michael Sternad
M. Winter
Y. Ohashi
T. Fujii
S. Kinoshita

NONAQUEOUS ELECTROLYTE SOLUTION FOR SECONDARY BATTERY AND NONAQUEOUS ELECTROLYTE SECONDARY BATTERY..

(2009)

Patentschrift

Michael Sternad
M. Winter
J. Besenhard
P. Raimann

Temperaturkontrollierte in-situ Gasdruckmessung für elektrochemische Systeme.

(2009)

Vortrag

B. Fuchsbichler
C. Stangl
H. Kren
C. Bayer
C. God
Michael Sternad
et al.

A New High Capacity Graphite-Core / Silicon-Shell Composite Material for Lithium Ion Batteries.

Wien, Österreich 2009.

(2009)

Zeitschriftenartikel

Michael Sternad
M. Cifrain
D. Watzenig
G. Brasseur
M. Winter

Condition monitoring of Lithium-Ion Batteries for electric and hybrid electric vehicles.

In: e & i Elektrotechnik und Informationstechnik (vol. 126) , pg. 186-193

(2009)

DOI: 10.1007/s00502-009-0644-2

Abstract anzeigen

Since the early 1990s Lithium-Ion Batteries have stated a key technology in rechargeable batteries due to their high volumetric and gravimetric energy densities and were first introduced in personal devices like camcorders, cellular phones and mobile computers ("3-C applications"). Ongoing evolutionary advances release at present a new spate of research activities to extend the operational area of small-sized batteries with the final aim to achieve reliable energy storage in automotive environments (e.g. hybrid vehicles). High absolute energy amounts of large-scale Lithium-Ion Batteries raise safety and lifetime issues and set demands for methods to monitor the health conditions of batteries for automotive applications. By observing significant system variables, imminent failures of single cells or battery packs are in many cases predictable and suitable counteractions can be initiated. The paper gives a brief introduction to the state-of-the-art of advanced batteries for electric and hybrid electric vehicles. Special focus is put on the monitoring of safety-relevant system parameters like cell-voltage, system temperature and headspace-pressure, their significance on the battery's state-of-health (SOH) and possible cell-failures. Different in-situ, ex-situ and onboard measurement techniques are addressed.

Vortrag

H. Kren
S. Koller
R. Hohl
Michael Sternad
F. Stelzer

Post Mortem Analysis of SEI Components in Industrial Lithium-Ion Cells for Determination of Ageing Effects. Poster presentation.

Wien, Österreich 2009.

(2009)

Vortrag

C. Stangl
C. Bayer
O. Fruhwirth
B. Fuchsbichler
C. God
R. Hohl
Michael Sternad
et al.

Alternative Binder Systems for Lithium Ion Batteries 2009.

Wien, Österreich 2009.

(2009)

Vortrag

Michael Sternad
H. Kren
R. Hohl
C. Bayer
C. God
C. Stangl
et al.

The Influence of Fluorinated Aromatic Isocyanates (FAI) on the Cycling Perfomance of Silicon Anodes in Lithium-Ion Batteries. Poster presentation.

Wien, Österreich 2009.

(2009)

Zeitungsartikel

Michael Sternad
H. Schorn

Linzer erforschte, wie Batterien sieben Mal länger funktionieren.

In: Oberösterreichische Nachrichten pg. 29

04.05.2009 (2009)

Zeitungsartikel

Michael Sternad
J. Schafferhofer

Wissen: "Die Batterie von morgen"..

In: Kleine Zeitung / Stadtausgabe

06.09.2009 (2009)

Zeitungsartikel

Michael Sternad
V. Schmidt

Dissertation der Woche: "Im Akku reißt und bröckelt nichts mehr".

In: Die Presse pg. 23

11.10.2009 (2009)

Patentschrift

Michael Sternad
M. Winter
Y. Ohashi
T. Fujii
S. Kinoshita

NONAQUEOUS ELECTROLYTE SOLUTION FOR SECONDARY BATTERY AND NONAQUEOUS ELECTROLYTE SECONDARY BATTERY..

(2010)

Vortrag

Michael Sternad
B. Fuchsbichler
C. God
M. Takehara
M. Ue
M. Winter

More Silicon for more Miles? A wayto High-Energy Lithium-Ion Batteries through finishing the Silicon-Anade with Fluorinated Aromatic Isovyanates (FAI).

Montreal, Kanada 2010.

(2010)

Vortrag

C. God
O. Moser
C. Bayer
R. Hohl
C. Stangl
Michael Sternad
et al.

Investigation of the oxidative stability of electrolyte systems on 5V cathode materials by insitu mass spectrometry. Poster presentation.

Montreal, Kanada 2010.

(2010)

Patentschrift

Michael Sternad
M. Winter
Y. Ohashi
T. Fujii
S. Kinoshita

NONAQUEOUS ELECTROLYTE SOLUTION FOR SECONDARY BATTERY AND NONAQUEOUS ELECTROLYTE SECONDARY BATTERY..

(2010)

Vortrag

B. Fuchsbichler
C. Stangl
H. Kren
Michael Sternad
C. Bayer
C. God
et al.

A New High Capacity Graphite/Silicon Composite Material for Lithium Ion Batteries. Poster presentation.

Montreal, Kanada 2010.

(2010)

Vortrag

M. Forster
Michael Sternad
K. Schmut
B. Goller
P. Schweizer
M. Sorger

Theorie vs Praxis - Ist gewünscht gleich machbar?.

Wien, Österreich 2011.

(2011)

Vortrag

Michael Sternad

Die Lithium-Ionen-Batterie - von der Knopfzeile zur Traktionsbatterie.

Linz, Österreich 2013.

(2013)

Vortrag

Michael Sternad
G. Schrotter
A. Dunst
R. Janski
M. Forster
B. Goller
et al.

Crystalline Silicon as Structured Anode Material for Lithium-Ion Batteries.

San Francisco, CA, USA 2013.

(2013)

Vortrag

H. Kren
R. Hohl
Michael Sternad
M. Cifrain
S. Koller

Ex-Situ Method for the Determination of Lithium and Fluoride trapped in the SEI of Lithium Ion Cells during prolonged cycling.

Graz, Österreich 2013.

(2013)

Patentschrift

Michael Sternad
M. Forster
K. Schmut
B. Goller
Zieger G.
M. Sorger
P. Schweizer

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

(2013)

Patentschrift

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.

(2013)

Zeitungsartikel

Michael Sternad
T. Weibold
M. Wilkening

Die Leistung steigt, der Preis fällt.

In: Oberösterreichische Nachrichten pg. 30

28.12.2013 (2013)

Patentschrift

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)

Patentschrift

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)

Patentschrift

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)

Zeitschriftenartikel

R. Janski
M. Fugger
Michael Sternad
M. Wilkening

Lithium Distribution in Monocrystalline Silicon-Based Lithium-Ion Batteries.

In: ECS Transactions (The Electrochemical Society) (vol. 62) , pg. 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.

Patentschrift

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)

Vortrag

A. Dunst
Michael Sternad
V. Epp
M. Wilkening

Li Self-Diffusion in Metastable Li15Si4 prepared from Monocrystalline Si - An Ex Situ 7Li NMR Relaxometry Study. Poster presentation.

Como, Italien 2014.

(2014)

Vortrag

R. Janski
M. Fugger
Michael Sternad
M. Wilkening

Lithium Distribution in Monocrystalline Silicon based Lithium-Ion Batteries. Poster presentation.

Como, Italien 2014.

(2014)

Vortrag

A. Dunst
Michael Sternad
V. Epp
M. Wilkening

Li Self-Diffusion in Amorphous Li/Si Prepared from Monocrystalline Si - A 7Li NMR Relaxometry Study. Poster presentation.

Lausanne, Schweiz 2014.

(2014)

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.

In: The Journal of Physical Chemistry C (vol. 119) , pg. 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.

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.

In: Solid State Ionics (vol. 276) , pg. 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.

Vortrag

A. Dunst
Michael Sternad
V. Epp
M. Wilkening

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

Wien, Österreich 2015.

(2015)

Patentschrift

Michael Sternad
K. Rowold

Zelle eines Energiespeichers für ein Fahrzeug.

(2015)

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.

Keystone, CO, USA 2015.

(2015)

Vortrag

H. Bülter
Michael Sternad
M. Wilkening
G. Wittstock

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

Glasgow, United Kingdom 2015.

(2015)

Zeitschriftenartikel

H. Bülter
Michael Sternad
M. Wilkening
G. Wittstock

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

In: ECS Transactions (The Electrochemical Society) (vol. 68) , pg. 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.

Patentschrift

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)

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.

In: Chemistry of Materials (vol. 27) , pg. 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.

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.

Graz, Österreich 2015.

(2015)

Vortrag

Michael Sternad
M. Forster
M. Wilkening

Powering the Digital Revolution: A Miniaturized Lithium Battery Made of Single-Crystalline Silicon. Poster presentation.

Chicago, IL, USA 2016.

(2016)

Zeitschriftenartikel

A. Dunst
Michael Sternad
M. Wilkening

Overall conductivity and NCL-type relaxation behavior in nanocrystalline sodium peroxide Na 2 O 2 —Consequences for Na-oxygen batteries.

In: Materials Science and Engineering: B (vol. 211) , pg. 85-93

(2016)

DOI: 10.1016/j.mseb.2016.06.002

Abstract anzeigen

Metal air batteries are considered as promising candidates for room-temperature batteries with high-energy densities. On discharge, atmospheric oxygen is reduced at the positive electrode which, in the ideal case, forms the discharge products in a reversible cell reaction. In Na-O2 batteries upon discharge either sodium peroxide (Na2O2) or sodium superoxide (NaO2) is reported to be formed. So far, the charge carrier transport remains relatively unexplored but is expected to crucially determine the efficiency of such energy storage systems. Na2O2 is predicted to be an electrical insulator wherein the transport presumably is determined by very slow hopping processes. Understanding the basic fundamental properties of the overall charge carrier transport, including also nanostructured forms of Na2O2, is key to developing high-energy metal oxygen batteries. The present study answers the question how overall, i.e., total, conductivity changes when going from microcrystalline to nanocrystalline, defect-rich Na2O2. Nanocrystalline Na2O2 was prepared via a top-down approach, viz by high-energy ball milling. Milling does not only shrink the average crystallite diameter but also introduces a large amount of defects which are anticipated to influence total conductivity. It turned out that even after vigorous mechanical treatment the conductivity of the sample is only increased by ca. one order of magnitude. The activation energy remains almost untouched. Thus, the increase seen might be attributed to an enhanced number of charge carriers. Low-temperature data reveals nearly constant loss relaxation behavior which has frequently explained in terms of strictly localized electrical relaxation processes.

Vortrag

Michael Sternad
M. Wilkening

A Microbattery Made from Monocrystalline Silicon.

Graz, Österreich 2016.

(2016)

Vortrag

M. Uitz
Michael Sternad
M. Wilkening

Ageing studies on commercial 18650 batteries used in Tesla model S electric vehicles. Poster presentation.

Nantes, France 2016.

(2016)

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.

In: Journal of The Electrochemical Society (vol. 163) , pg. A504–A512

(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.

Vortrag

Michael Sternad

Die große Macht der kleinen Ionen - was Lithium-Ionen-Batterien zm Erfolg führt(e).

Kuchl, Österreich 2016.

(2016)

Vortrag

M. Uitz
Michael Sternad
M. Wilkening

Ageing of Commercial 18650 Batteries Used in Tesla Model S Electric Vehicles.

Chicago, IL, USA 2016.

(2016)

Zeitschriftenartikel

Michael Sternad
M. Forster
M. Wilkening

The microstructure matters: breaking down the barriers with single crystalline silicon as negative electrode in Li-ion batteries.

In: Scientific Reports (Nature Publishing Group) (vol. 6)

(2016)

DOI: 10.1038/srep31712

Abstract anzeigen

Silicon-based microelectronics forms a major foundation of our modern society. Small lithium-ion batteries act as the key enablers of its success and have revolutionised portable electronics used in our all everyday's life. While large-scale LIBs are expected to help establish electric vehicles, on the other end of device size chip-integrated Si-based μ-batteries may revolutionise microelectronics once more. In general, Si is regarded as one of the white hopes since it offers energy densities being ten times higher than conventional anode materials. The use of monocrystalline, wafer-grade Si, however, requires several hurdles to be overcome since it its volume largely expands during lithiation. Here, we will show how 3D patterned Si wafers, prepared by the sophisticated techniques from semiconductor industry, are to be electrochemically activated to overcome these limitations and to leverage their full potential being reflected in stable charge capacities (>1000 mAhg(-1)) and high Coulomb efficiencies (98.8%).

Zeitschriftenartikel

M. Uitz
Michael Sternad
S. Breuer
C. Täubert
T. Traußnig
V. Hennige
I. Hanzu
M. Wilkening

Aging of Tesla's 18650 Lithium-Ion Cells: Correlating Solid-Electrolyte-Interphase Evolution with Fading in Capacity and Power.

In: Journal of The Electrochemical Society (vol. 164) , pg. A3503–A3510

(2017)

DOI: 10.1149/2.0171714jes

Abstract anzeigen

The long-term performance of commercial lithium-ion batteries used in today's electric vehicles is of utmost importance for automotive requirements. Here, we use Tesla's 18650 cells manufactured by Panasonic to elucidate the origins of capacity fading and impedance increase during both calendar and cycle aging. Full cell testing is systematically carried out at three different temperatures (25°C, 40°C, 60°C). The cells are galvanostatically cycled at different C-rates (0.33 C – 1 C) and calendar aging is monitored at 4 different state-of-charges (SOC). Operation at high temperatures turns out to have the largest effect on both the capacity and direct current (DC) impedance. As an example, after 500 cycles at 25°C and 40°C capacity fading is approximately 12%, while at 60°C the fading reaches 22%. Our DC impedance measurements reveal the same trend. Post mortem analysis indicate that aging is strongly related to changes of the solid electrolyte interphase (SEI). Hence, the changes in performance are correlated with the change in composition (and thickness) of the SEI formed. In particular, we quantitatively measure the formation of electrically insulating LiF and find a correlation between overall DC impedance of the cells and lithium fluoride of the SEI.

Patentschrift

Michael Sternad
R. Janski
K. Schmut
M. Wilkening
K. Karlovsky
M. Sorger
A. Dunst
G. Hirtler

VERFAHREN ZUM HERSTELLEN EINER BATTERIE, BATTERIE UND INTEGRIERTE SCHALTUNG..

(2017)

Patentschrift

K. Karlovsky
A. Dunst
G. Hirtler
R. Janski
K. Schmut
M. Sorger
Michael Sternad
M. Wilkening

METHOD OF MANUFACTURING A BATTERY, BATTERY AND INTEGRATED CIRCUIT.

(2017)

Zeitschriftenartikel

R. Janski
M. Fugger
M. Forster
M. Sorger
A. Dunst
I. Hanzu
Michael Sternad
M. Wilkening

Lithium barrier materials for on-chip Si-based microbatteries.

In: Journal of Materials Science: Materials in Electronics (vol. 28) , pg. 14605-14614

(2017)

DOI: 10.1007/s10854-017-7325-4

Abstract anzeigen

The integration of lithium-ion batteries, featuring ultra-high discharge rates, directly into silicon-based semiconductor devices opens unique paths towards the development of new mobile micro-electronics applications. Nevertheless, the small and mobile lithium ions have to be confined within the battery area of the silicon chip, otherwise the nearby fine microelectronics devices will be irreversibly damaged. Hence, a barrier material that blocks Li+ transport from the active components of the battery into the surrounding crystalline Si is needed. Here we evaluated the capability of magnetron sputtered barrier films of nitrides and alloys of refractory metals to prevent lithium ion diffusion and, thus, the formation of Li–Si phases outside the battery area. In order to determine the Li profiles in the barrier layer and in the silicon substrate, time-of-flight secondary ion mass spectroscopy was applied for profiling the first microns. In combination with electrochemical testing it turned out that titanium nitride as well as tantalum nitride barriers are able to significantly block Li ion migration.

Patentschrift

M. Thannhuber
Michael Sternad

BATTERY PACK FOR AN ELECTRICAL DEVICE, CHARGING DEVICE FOR A BATTERY PACK AND METHOD FOR OPERATING A BATTERY PACK.

(2019)

Zeitschriftenartikel

E. dos Santos Sardinha
Michael Sternad
H. Wilkening
H. Martin
G. Wittstock

Nascent SEI-Surface Films on Single Crystalline Silicon Investigated by Scanning Electrochemical Microscopy.

In: ACS Applied Energy Materials (vol. 2) , pg. 1388-1392

(2019)

DOI: 10.1021/acsaem.8b01967

Abstract anzeigen

Silicon is a promising high-capacity host material for negative electrodes in lithium-ion batteries with low potential for the lithiation/delithiation reaction that is outside the stability window of organic carbonate electrolytes. Thus, the use of such electrodes critically depends on the formation of a protective solid electrolyte interphase (SEI) from the decomposition products of electrolyte components. Due to the large volume change upon charging, exposure of the electrode material to the electrolyte must be expected, and facile reformation of SEI is a scope for improving the stabilities of such electrodes. Here, we report the formation of incipient SEI layers on monocrystalline silicon by in situ imaging of their passivating properties using scanning electrochemical microscopy after potentiodynamic charging to different final potentials. The images show a local initiation of the SEI growth at potentials of around 1.0 V vs Li/Li+ in 1 M LiClO4 in propylene carbonate.

Zeitschriftenartikel

Michael Sternad
G. Hirtler
M. Sorger
D. Knez
K. Karlovsky
M. Forster
H. Wilkening

A Lithium‐Silicon Microbattery with Anode and Housing Directly Made from Semiconductor Grade Monocrystalline Si.

In: Advanced Materials Technologies , pg. 2100405

(2021)

DOI: 10.1002/admt.202100405

Abstract anzeigen

Miniaturized and rechargeable energy storage systems, which easily power smart and (in vivo) sensors or the wirelessly networked transmitting devices of the so-called internet of things, are expected to open unprecedented ways for how information can be shared autonomously. On the macroscale, such battery-powered devices have already revolutionized our daily life by the use of mobile phones and portable computers. The eagerly-awaited advent of sufficiently powerful and long-living microbatteries will definitely make our lives more comfortable, especially in sectors such as medicine, security, autonomous driving or artificial intelligence in conjunction with fields where information need to be quickly shared, also including pandemic-like situations. Here, a fully matured lithium-ion microbattery with millimeter-sized dimensions that can be manufactured by mass production methods well-established in semiconductor industry is presented. The battery can directly be machined from wafer-grade monocrystalline silicon which acts as both the electrochemically active anodic part and, at the same time, as the electrically insulating housing material of the accumulator. The high current output power (200 mW cm−2; 30 mA peak current) and the solid charge-discharge stability of at least 100 cycles (10 mAh cm−2), combined with a high Coulombic efficiency near 100%, make the device ideally suited to be implemented in a large range of intelligent, self-powered electric devices.

Beitrag in Sammelwerk/Tagungsband

Michael Furtmair
Anika Wolters
Fabian Kühnel
M. Thannhuber
V. Sötz
Michael Sternad

The Impact of Fast-Charging on Cell Ageing of Industrial High-Power Lithium-Ion Batteries.

(2022)

Zeitschriftenartikel

Michael Furtmair
Anika Wolters
S. Simic
M. Thannhuber
Günther Ruhl
Michael Sternad

Tracing the Powerfade: Location and Quantification of the Fluoridic Solid Electrolyte Interphase on Graphite Anodes.

In: ECS Meeting Abstracts (vol. MA2023-01) , pg. 2860-2860

(2023)

DOI: 10.1149/MA2023-0172860mtgabs

Abstract anzeigen

Due to the conversion of the global energy supply from carbon emitting to renewable sources, there is the need for energy storage systems being efficient at high energy- and power densities. Many requirements are fulfilled best by Lithium-Ion Batteries (LIBs), so this technology is successfully part of battery-electric vehicles, cordless power tools and portable electronic devices. The ongoing improvement of anode- and cathode materials, together with adapted electrolytes [1] led to excellent advances in power- and energy densities. However, the increasing amount of total energy per cell underlines the importance of monitoring the cell's health parameters (e.g. capacity fades, coulombic efficiencies, AC-and DC-impedances) in order to ensure safety and expand the lifetime [2, 3]. The Solid Electrolyte Interphase (SEI) represents a main source for cell impedances [4] and was in the case of LiPF6-based electrolytes found to be best analytically accessible by the quantitative determination of its unsolvable, fluoridic fractions (LiF) using ion-exchange chromatography [5]. During this work, long term cycling tests (T = 25, 40, 60 °C, 2 C charging) of industrial 3 Ah-21700-cells with graphite anode (figure a), NMC 811 cathode and LiPF6-based electrolyte were performed (figure b). Subsequently, after defined cycling steps (10, 250, 500, 750 cycles) the cells were opened, post-mortem analysis (SEM, EDX, "broad ion beam"- (BIB) preparation) together with the drawing of anode/separators samples for the later fluoride determination took place. The samples were cleaned from LiPF6 (washing with DEC) and dried under glovebox conditions (Ar, < 0.5 ppm H2O). With the aim to quantify the SEI layer 1) in the anode bulk and 2) adhering to or inside the separator to trace reversible Li-plating, anode/separators samples were eluted separately with deionized water and the fluoride-concentration of the solutions was determined by ion-exchange chromatography (figure c - f). SEI fractions, like inorganic carbonates, alkyl carbonates, oxides, etc., were investigated using X-ray photoelectron spectroscopy (XPS) along a depth profile (figure g) using Ar-ion sputtering [6, 7]. The results elaborated within this study point out a strong correlation in between the amount of fluoridic SEI and the DC-impedance rise during cycling, especially at elevated temperatures (40, 60 °C). At 25 °C different ageing mechanisms are obvious: In comparison lower fluoride concentrations together with substantial DC impedance gains suggest the temporary and superficial occurrence of reversible Li-plating, blocking important Li-ion paths via the electrolyte (e.g. anode surface pores, separator pores [8, 9]) by residual products of their SEI-films.

Vortrag

Denis Düzgün
J. Schwab
M. Steckel
A. Hahn
Michael Sternad

Application-Related Fast-Charging Strategies via in-situ Monitoring of Lithium-Ion-Batteries. Poster presentation (P72).

Strasbourg, France 13.-16.05.2024.

(2024)

Vortrag

Luca Lieb
Anika Wolters
Michael Furtmair
M. Thannhuber
Günther Ruhl
Michael Sternad

The Influence of Dry Air on Lithium Metal Batteries. Poster presentation.

The Electrochemical Society, Inc..

San Francisco, CA, USA 26.-30.05.2024.

(2024)

Vortrag

Luca Lieb
Michael Furtmair
P. Hawe
Anika Wolters
M. Thannhuber
Günther Ruhl
Michael Sternad

Seeding and Growing Plain Li-Metal Surfaces - New Approaches to Increase the Coulombic Efficiency of Anodeless Lithium-Metal Batteries.

The Electrochemical Society, Inc..

San Francisco, CA, USA 29.05.2024.

(2024)

Labore

Energiespeichersysteme

TC Plattling

Sustainable Production & Energy Technologies

Labore

Labor für Elektrochemische Energiespeichersysteme am TC Plattling (https://www.th-deg.de/tc-plattling)

Forschungs- und Lehrgebiete

Google Scholar: https://scholar.google.com/citations?hl=de&user=gOoGAtQAAAAJ publons: https://publons.com/researcher/1743781/michael-sternad/ ORCID iD: https://orcid.org/0000-0001-9307-222X