Akitoshi Hayashi

7/21/2019 Akitoshi Hayashi

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Akitoshi Hayashi and Masahiro Tatsumisago

(Osaka Prefecture University, Japan)

Osaka Prefecture University

Development of all-solid-state lithium batterieswith sulfide solid electrolytes

International Battery Association (IBA) 2013 Meeting , Barcelona, Spain March 13, 2013



2Outline


1. Background

Motivation of all-solid-state rechargeable batteries

2. Sulfide glass solid electrolytes

3. All-solid-state Li batteries with sulfide electrolytes

Approaches to fabricate favorable electrode-electrolyte interfaces

4. Na+ ion conductors for all-solid-state Na batteries

5. Summary



3

Organic liquid electrolyte

L i+L i+

L i+L i+

L i+

L i+

L i+

X -

X -

X -

L i+L i+

L i+L i+

anode

C CoO 2

cathode


Demand for all-solid-state battery

Serious safety problems becomeobvious and thus improving safety ofbatteries (especially large-sizedbatteries) is a big issue to be solved.

Lithium-ion battery

innovative battery forthe next generation

Inorganic solid electrolyte

L i+L i+

L i+

L i+

L i+

L i+L i+

L i+

L i+

L i+ L i+ L i+

cathode

all-solid-state battery

anode

remove safety hazards ofleakage, volatilization andflammability

Stacked → high voltage

○high safety○long cycle life○high energy density・stacked battery・possibility of use of high

capacity electrodes

（Li metal, elemental S ）


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Solid Electrolyte

Substrate

Negative Electrode

Positive Electrode

Thin-film battery

10m

Bulk-type battery

Positive

Electrode

Solid

Electrolyte

Negative

Electrode

1mm

Electrode Material Conductive additive Solid Electrolyte

Consisting of powder-compressed layersof electrode and electrolyte

high energy density !

Key points:1. Solid electrolytes with high conductivity2. Favorable contact at solid-solid interface

Li / LiPON / LiCoO2

Data from the web site of Excellatron

Long cycle performance

Two types of all-solid-state rechargeable lithium batteries 4



Merits of inorganic solid electrolytes

○Single cation conduction

○Wide electrochemical window

○Simple electrochemical reactions

Why inorganic solid electrolytes? 5

in EC+DECxLi2S・(100-x)P2S5 glass

M. Chiku et al., Electrochemistry, 80, 740 (2012).

(Li / electrolyte)

K. Minami et al., Solid State Ionics, 192, 122 (2011).

charge-transfer reaction at electrode





10-9

10-8

10-7

10-6

10-5

10-4

10-3

10-2

10-1

100

1.8 2 2.2 2.4 2.6 2.8 3 3.2 3.4

C o n d u c t i v

i t y / S c m - 1

1000 T-1 / K -1

240 oC360 oC

Solid-state reaction

550 oC

glass

10 15 20 25 30 35 40

I nt e n

sit

y( a

rb . u nit)

2 /o

(CuK)

glass

240 oC

360 oC

550 oC

Solid-state

reaction: Li7P3S11

: Li3.2P0.96S4 : Li4P2S6

: Li3PS4

7

F. Mizuno et al., Adv. Mater ., 17, 918 (2005); Solid State Ionics., 177, 2721 (2006). Osaka Prefecture University

Precipitation of superionic Li7P3S11 phase from the 70Li2S・30P2S5 (mol%) glass

The formation of a superionicmetastable phase is responsiblefor increasing conductivity ofglass-based solid electrolytes.



Liquid electrolytes

C

vty/Scm-

Temperature ( oC )

Li2O-B2O3-LiCl glass

Li2O-Nb2O5 glass

Li3.4V0.4Ge0.6O4

crystal

La0.51Li0.34TiO2.94 crystal

Li3N crystal

Li2S-SiS2-P2S5-LiI glass

Li1.3 Al0.3Ti1.7(PO4)3 crystal

Li3.3PO3.8N0.22 glass (LiPON)

1000 T-1 / K-1

25 100 200 300 0

1.5 2 2.5 3 3.5

10 0

10 -1

10

-2

10 -3

10 -5

10 -4

10 -6

Li3.25P0.75Ge0.25S4

thio-LISICON II Li7P3S11 glass-ceramic25= 5 x 10-3 Scm-1

Li+ ion conductivity of the

sulfide solid electrolytesis now higher than that ofliquid electrolytes!

Li7

P3

S11

glass-ceramic

25= 1 x 10-2 Scm-1

Seino et al., 36th Solid State Ionics Meetingin Japan (2010).

Li10GeP2S12 crystal

Kamaya, Kanno et al, Nat. Mater.,10, 682 (2011).

25= 1.2 x 10-2 Scm-1

8Solid electrolytes with high lithium ion conductivity

T. Minami ed., “Solid State Ionics for Batteries”, Springer, Tokyo, p. 1 (2005).

Adv. Mater., 17, 918 (2005).

J. Non-Cryst. Solids, 356, 2670 (2010).




0

0.5

1

1.5

2

2.5

60 70 80 90 100

Mol % Li2S

H 2

S a m o u n t / c m

3 g

- 1 ( 1

m i n )

200300400500600700

I n t e n s i t y ( a

r b .

u n i t )

Wavenu mber / cm -1

PS43

75Li2S･25P2S5 glass

before

PS43

PS43 S S

S

S

P

Main structural unit (PS43-) did not

change after exposure to air for 1day.

after exposureto air for 1day

Chemical stability in air of sulfide electrolytes

Osaka Prefecture UniversityH. Muramatsu et al., Solid State Ionics, 182 (2011) 116.

Hydrolysis is suppressed.

H2S generation(R.H. 50%)

Sulfide solid electrolytes with moderate chemical stability in air atmosphere

are prepared by selecting compositions.

9

Li2S-P2S5 glasses



10Outline


1. Background




Approaches to fabricate favorable electrode-electrolyte interfaces

4. Na+ ion conductors for all-solid-state Na batteries

5. Summary



11

Li2S-P2S5 glass-ceramic

Stainless-steel(current collector)

Polycarbonate

(insulator)

conductive additiveactive materialSE = 60 : 40 : 4 (wt %)

Composite electrode


Solid electrolyte (SE):

Application to bulk-type all-solid-state batteriesApplication to bulk-type all-solid-state batteries

The formation of Li+ and e-

conduction paths to activematerial particles is significant.

Counter electrode：Li-In alloy

(reference electrode)

Working electrode: e.g. Li4Ti5O12

screw

Li+

e-

12



Li-In / 70Li2S･29P2S5･1P2S3 glass-ceramic / Li4Ti5O12

The cell operated at a high current density of 12.8 mA cm-2

and kept the capacity of 130 mAh g-1 for 700 cycles.


100 oC

K. Minami et al., Solid State Ionics, 192 (2011) 122.

12Electrochemical performance of bulk-type solid-state batteries

12.8

A h f b i f bl l d l l i f



13Approaches to fabricate favorable electrode-electrolyte interfaces

Li / S

batteries

M. Tatsumisago, M. Nagao, A. Hayashi.

Journal of Asian Ceramic Societies, in press.

14S lfid l l i LiC O l d b PLD



Ar filled glove box

KrF excimer laser

（ = 248 nm ）

Vacuum chamber

Target Pellet of mixture of Li2S

and P2S5 crystalline powder

（80Li2S･20P2S5 mol%）

Ambient gas Ar gas (5 Pa)

Temperature Room temperature

Frequency 10 Hz

Laser fluence 2 J cm-2

Target-substrate dis tance 7 cm

Deposition conditions

14Sulfide electrolyte coating on LiCoO2 electrode by PLD

vibrator

Li2S-P2S5 electrolyteLiNbO3-coated

LiCoO2*

Li2S-P2S5 target

KrF Excimer laser(248 nm)

Surface coating using PLD

PLD

(80Li2S･20P2S5)

* N. Ohta, K. Takada et al. Electrochem. Commun. 9, 1486 (2007).

All s lid st t lls si SE t d LiC O 15



LiCoO2 positiveelectrode

Li2S-P2S5 electrolyte

All-solid-state cells using SE-coated LiCoO2

A. Sakuda et al, J. Power Sources, 196 (2011) 6735.

1

2

3

4

5

0 20 40 60 80 100 120

C e l l v o l t a g e / V

Capacity / mAh g-1

(LiCoO2+Li

2S-P

2S

5)

With SE particles

With SE coatings

With SE particles(30 wt% SE particleswere mixed)

With SE coatings(10 wt% SE filmswere coated)

In / Li2S-P2S5 / LiCoO2

0.13 mA cm-2

Lithium-ion conducting paths are formedwith small amounts of solid electrolytes.

5 m

LiCoO2

LiCoO2

LiCoO2

Li2S-P2S5

LiCoO2

Cross-sectional SEM image

15

All lid t t Li / S b tt i



Sulfur positive electrode in all-solid-state cells shows a good cycle performance.

All-solid-state Li / S batteries 16

M. Nagao, A. Hayashi, M. Tatsumisago, Electrochim. Acta, 56, 6055 (2011).

In / LiCoO2

25

o

C0.064 mA cm-2

2

1

0

3

4

5

0 400 800 1200 1600

C e l l p o t e

n t i a l v s . L i / V

Capacity / mAh g-1

Li-In / S

charge

discharge

S + xLi+ + xe- LixSdischarge

charge

Sulfur active material・abundant element・large theoretical capacity

(1672 mAh g-1)

Li-In / 80Li2S・20P2S5 (SE) / 25S・25AB・50SE (wt%)

I f th lf t t i iti l t d



Li-In / SE / 50S・20AB・30SE (wt%)

25 oC

0.064 mA cm-2

0.64 mA cm-2 (0.2 C)

0.064

mA cm-2

0 10 20 30 40 500

200

400

600

800

1000

1200

1400

Cycle number

C a p a c i t y

/ m A h g - 1

( s u l f u r )

17

M. Nagao et al., Energy Technology, in press.

Increase of the sulfur content in a positive electrode

Ball-milling the S-AB composite at 155oC(the lowest viscosity coefficient of sulfur)

200 nm

C; blue, P; green, S; red

e－

e－

e－

Li＋

e－

Li＋

Li＋

Li＋

AB

sulfur

Li2S-P2S5

SE

Cross-sectional

EELS mapping

・Energy density based on the weight of the totalpositive electrode is increased (1007 Wh kg-1).

・Sulfur with the size less than 200 nm and ABparticles are homogeneously dispersed in the SEmatrix. large capacity & good cyclability

18Outline



18Outline


1. Background




Approaches to fabricate favorable electrode-electrolyte interfaces4. Na+ ion conductors for all-solid-state Na batteries

5. Summary

Why Na batteries? 19



Why Na batteries?

Sodium-sulfur (NAS) batteries ・Large energy density (760 Wh kg-1)・High-temperature operation (＞300 oC)・Strict security apparatus

Na / sintered -alumina / S(liquid) (solid) (liquid)

Limitation of usage environment

Na+ ion batteries

Next-generation batterieswith high energy densityusing abundant sodium

sources

19

*

*J.O. Besenhard and M. Winter, CHEMPHYSCHEM , 3, 155 (2002).

All-solid-state Na/s batteries operating at room temperature arestrongly desirable from safety point of view.

New solid electrolytes suitable for solid-state batteries


New Na+ ion conducting sulfide electrolytes 20



10-6

10-5

10-4

10-3

10-2

10-1

2 2.5 3 3.5

C o

n d u c t i v i t y / S

c m - 1

1000 T-1 / K-1

Glass

Glass-ceramic

75Na2S･25P2S5 (mol%) = Na3PS4

Conductivity increases by crystallizationof the Na3PS4 glass.

A. Hayashi et al., Nature Communications, 3 (2012) 856.

New Na ion conducting sulfide electrolytes 20

A cubic Na3PS4 phase, which has notbeen reported, is precipitated inthe glass-ceramic electrolyte.

XRDConductivity

25 = 2×10-4 S cm-1


Application to all solid state sodium batteries 21



The all-solid-state sodium battery with the Na3PS4 electrolyte ischarged and discharged for 10 cycles and shows a good cycleability

at room temperature.

25 oC, 0.013 mA cm-2, 1.17-2.40 V

C e l l p o

t e n t i a l v s .

N a - S n / V

cubic-Na3PS4

glass-ceramic

Stainless steel

(current collector)

Solid electrolyte (SE):

Counter/referenceelectrode:Na-Sn alloy

Working electrode:TiS2：SE=2:3

(wt ratio)

Na-Sn / Na3PS4 / TiS2Na-Sn / Na3PS4 / TiS2

Application to all-solid-state sodium batteries 21

Osaka Prefecture UniversityA. Hayashi et al., Nature Communications, 3 (2012) 856.

Summary



Summary

1. Sulfide glass-based materials have favorable properties as solid

electrolyte for bulk-type all-solid-state batteries. Especially, the glass-ceramics in the system Li2S-P2S5 show high Li+ ion conductivities of 10-3

to 10-2 S cm-1, which are higher than those of liquid electrolytes.

2. Electrochemical performance of all-solid-state Li batteries has beendeveloped by the modification of the electrode-electrolyte interface.

3. Cubic-Na3PS4 glass-ceramic electrolyte with the conductivity of 10-4 S

cm-1 is prepared and all-solid-state Na batteries with the electrolyteoperate at room temperature.

AcknowledgementsThis work was financially supported by・Grant-in-Aid for Scientific Research from MEXT ・CREST and ALCA projects from JST ・Toyota Motor Co.

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Akitoshi Hayashi