Austrian Institute of Technology...• Reinhard Wagner, et al, Crystal structure of garnet-related...
Transcript of Austrian Institute of Technology...• Reinhard Wagner, et al, Crystal structure of garnet-related...
SOLIKLi-hochleitende Keramiken für all-solid-state Batterien
Dr. Ningxin ZHANG
Electric Drive Technologies
Center for Low-Emission Transport
Austrian Institute of Technology GmbH
Outline
• Basic Data
• Project vision
• Good reasons for project
• Progress
• Perspectives
• Conclusion
312.04.2017
• Name of Institute:
• Austrian Institute of Technology GmbH
• Name and E-Mail of project leader:
• Ningxin ZHANG, [email protected]
• Partners:
• Paris-Lordon University Salzburg, Inst. Mater. Chem. & Phys.
• Technical University of Vienna, Inst. Tech. Chem.
• Förderprogramm: e!Mission.at, 4th Call
• Project Number: 843882
• Duration: 01 May 2014 – 31 October 2017 (extended)
• Project budget: 701,409.00€
Basic data
412.04.2017
• Developing garnet structured electrolytes with the highest Li+ conductivity
through optimized strategy on doping and synthesis (PLUS).
• Uncovering the relationship between Li+ conductivity and materials
paramters of garnet electrolytes (TUW & AIT)
• Assembly and characterization of prototype all-solid-state LIBs (AIT)
Visions
512.04.2017
Why All-Solid-State
LIB:
• Green emobility
• Safety
Good reasons / Excellence
Why garnet structured LLZO
(Li7La3Zr3O12) electrolyte
• Phase structure
• Doping strategy
Know-how on
preparation of prototype
• Size effect
• Integration process
Dong Ok Shin, et al,
Scientific Reports, DOI:
10.1038/srep18053
Yuki Kato, et al, Nature Energy, DOI:
10.1038/NENERGY.2016.30
John Christopher Bachman, et al,
Chemical Review, DOI:
10.1021/acs.chemrev.5b00563.
OUTLET
• Basic Data
• Project vision
• Excellence of project
• Progress: synthesis of LLZO
• Perspectives
• Conclusion
712.04.2017
• Synthesis strategies:
• Solid-state process
• Sol-gel process
LLZO powders synthesisSolid state process
Sol-gel method
calcinationgelgelationsol
812.04.2017
Sol-gel process
Solid state process
LLZO powders synthesis: XRD
912.04.2017
Sintering parameters
Sol-gel processSolid state process
Li 7
La
3Z
r 2-x
Nb
xO
12
For powders synthesized via sol-gel process,
small grains are obtained.
For powders prepared with solid-state
process, an optimized sintering strategy of
lower temperature with prolonged time helps
to grow large crystals.
1012.04.2017
Al Ga Ta Nb
method
solid state yes yes no Yes
sol-gel no no yes Yes
Doping level x(y) (per
formula unit)
0.15/0.20/0.3/0.
40
0.15/0.20/0.30/0.
40
0.25/0.50/0.7
5/1.00/1.25/1.
50/1.75/2.00
0.25/0.50/0.75/
1.00/1.25/1.50/
1.75/2.00
Temperature
(°C)synthesis 850°C/1050°C/1200°C 900°C/1100°C/1200°C
Finished compositions
D3+xLi7-xLa3Zr2O12 Li7-yLa3Zr2-yD
5+yO12
OUTLET
• Basic Data
• Project vision
• Excellence of project
• Progress: measuring Li+ conductivity
• Perspectives
• Conclusion
Type Metal paste Sputtered film Metal foil
Materials Ag/Pt/Au Au/Pt/Li Li
Treated
Temperature200~300oC RT RT/170oC
Electrode-
eletrolyte
interface
1212.04.2017
Electrode configuration
13
12.04.2017
J.Am.Ceram.Soc.,98(2015)1209-1214
Rb RgbRb
Rb+Rgb
Solid State Ioncs,177(2006)2611-2615
Overall R
J. Power Sources, 206(2012)236-244
Sputtered Au as electrodes Li foil as electrodes Sputtered Pt as electrodes
Analysis of EIS
1412.04.2017
Microelectrodes
Tip (W)
LLZO
Microelectrodes
Heat or cooling
Impedance Analyzer
Counter electrode
Counter electrode: Ti/Pt
Electrode: 10 nm Ti
200 nm PtØ: 10 - 300 µm
Material: Al 0.20 pfu
The application of microelectrodes makes it possible to identify the influence of grain
boundary.
1512.04.2017
EIS results with microelectrode
The distribution of Li+ conductivity in Al doped LLZO samples
~8mm
Repetitivity of EIS
Influence of electrode size
Coutour plot of Li+ conductivity
Selection of electrodes
Influence of electrode type• Targets:
• Clearify the influence of electrode/electrolyte interface on the ionic conductivity in
solid electrolyte
• Determnation of suitable electrode
• Samples:• 6 LLZO pellets doped with Ga 0.3 with the similar geometry
• Same sintering and post treatment processes
• Electrode configuration:
• Symmetric: Ag-LLZO-Ag // Au-LLZO-Au // Li-LLZO-Li
• Asymmetric: Ag-LLZO-Au // Ag-LLZO-Li // Au-LLZO-Li
• Assembled into coin cells in a glove box filled with Ar
1612.04.2017
EIS results
1712.04.2017
0
0,2
0,4
0,6
0,8
1
0 0,2 0,4 0,6 0,8 1
-Im
(Z)
(MΩ●
cm)
Re(Z) (MΩ●cm)
Au-LLZO-Au
Li-LLZO-Li
Li-LLZO-Au
Li-LLZO-Ag
Ag-LLZO-Au
23oC
J Phys Chem Lett, 2015,
6, 4599-4604.
1812.04.2017
0
1000
2000
0 1000 2000 3000 4000 5000
-Im
(Z)
(Ω)
Re(Z) (Ω)
23°C 29°C 37°C 45°C
57°C 66°C 78°C 92°C
LLZO-Nb-0.25
RT:
Grain σ = 3,52e-4 S/cm
Grain boundary σ = 6,26e-5 S/cmy = 3,1019x - 3,8978
R² = 0,9951
y = 6,0029x - 12,008R² = 0,9992
4
5
6
7
8
9
2,5 2,7 2,9 3,1 3,3 3,5
LnR
1/T*1000 (K-1)
Grain
Grain boundary
Linear (Grain)
Linear (Grain boundary)
EC-Lab
1912.04.2017
Summary of doping effects
Comment:
Doping effect of Al & Ga to Li is more
effective than that of Nb & Ta to Zr.
Daniel Rettenwander, et al, Chem Mater, 2016, 28, 2384-2392.
1,E-06
1,E-05
1,E-04
1,E-03
1,E-02
0 0,25 0,5 0,75 1 1,25 1,5 1,75 2
Ion
ic c
on
du
ctiv
ity
S/cm
Doping level (pfu)
Ta doped LLZO
Nb-doped LLZO
2012.04.2017
Arrhenius plot of conductivity of LLZO nanofiber
membrane, PNAS, doi/pnas.1600422113.
LLZO-Ga0.3pfu
A possible mechanism is the evoluton of space
charge layer as a function of temperature??
OUTLET
• Basic Data
• Project vision
• Excellence of project
• Progress: Preparation of all-solid-state LiBs
I. LLZO ceramic pellet
II. LLZO thick film on separator
III. LLZO thick film on anode
• Perspectives
• Conclusion
2212.04.2017
• Preparation of targets
• Structure & sintering
broken target due to thermal mismatchingbetween
Cu plate and LLZO ceramic
Thin Film battery
• Thin film deposition
Magnetron sputtering by Energy Department
of AIT in Tech Gate
LLZO ceramic pellet: half cell
2312.04.2017
-3,0E-06
-2,0E-06
-1,0E-06
0,0E+00
1,0E-06
2,0E-06
3,0E-06
-1 0 1 2 3 4 5
Cu
rren
t (A
)
Voltage (V)
1st CV
2nd CV
Graphite-LLZO(Al0.2)-Li
LLZO pellet
Graphite
Li foil
-300
-200
-100
0
100
200
300
2,5 3 3,5 4 4,5 5 5,5
Cu
rre
nt (µ
A)
Voltage (V)
LNMO-LLZO thick film-graphite
0
10
20
30
40
50
0 5 10 15 20 25 30 35
Specific
capacity (
mA
h/g
)
Cycle number
LNMO-LLZO thick film-graphite
24• CV curve showed lithiation & de-lithiation peaks
• ~30% of the specific capacity of LNMO reached
II. Thick LLZO film: full cell
Assembly EIS
C/2
1C4C 6C
2C
1C
1C
6C
C/5
LLZO thick film
/separator
LNMO
Graphite
2512.04.2017
• Direct coating of LLZO film on anode
• Co-calendaring of electrolyte-electrode composite film
III. LLZO-anode composite film
After coating
LLZO - anode composite film Li metal piece as counter
electrode
Electrochemical measurements ungoing…
Assembly into EL-CELL
Li foil
2612.04.2017
• Publications on peer reviewed journals:• Daniel Rettenwander, et al, Structural and electrochemical consequences of Al and Ga consubstituion in
Li7La3Zr2O12 solid electrolytes, Chemistry of Materials, 2016,28,2384-2392. (2016 IF: 9.407)
• Reinhard Wagner, et al, Crystal structure of garnet-related Li-ion conductor Li7-3xGaxLa3Zr2O12 : fast Li-ion
conduction caused by a different cubic modification? Chemistry of Materials, 2016,28,1861-1871. (2016 IF:
9.407)
• Andreas Wachter-Welzl, et al, Microelectrodes for local conductivity and degradation measurements on Al
stabilized Li7La3Zr2O12 garnets, Journal of Electroceramics, 2016, doi:10.1007/s10832-016-0058-6. (2016
IF:1.263)
• Conference paper:• Ningxin, Zhang, et al, Electrode interface effect on Li ionic conductivity of garnet solid electrolyte LLZO,
ABAA9, the 9th International Conference on Advanced Lithium Ion Batteries for Automotive Applications, 17-
20th October, 2016, Huzhou, China.
Dissemination of results
2712.04.2017
• Summary
• Combination among:
• Crystal structure and chemistry
• Electrical measurement and mechanism analysis
• Battery building and evaluation
• Perspective
• Gap to target
• Possibility to reach the target
Summary and perspectives
2812.04.2017
• Thanks for the finacial support of this project from:
• Thanks for the great cooperation within the project:
• Prof. Georg Amthauer, Prof. C.A. Geigther, Dr. Daniel Rettenwander, Dr. Reinhard
Wagner, and M. M. Maier et al from PLUS.
• Prof. Jürgen Fleig and Dr. Andreas Wachter-Welzl, Stenfanie Taibl et al from TU
Wien.
• Prof. Atanaska Trifonova and other colleagues from AIT.
Acknowledgment
THANK YOU!Ningxin ZHANG, 27th March 2017