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, ningxin.zhang@ait.ac.at

• 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