Solid-State Lithium Batteries Using Glass Electrolytes

Masahiro TATSUMISAGO

Department of Applied ChemistryGraduate School of Engineering

Osaka Prefecture UniversityJapan

International Workshop on Scientific Challenges on New Functionalities in GlassApril 15-17, 2007

AGENDA

• Introduction – Why all-solid-state battery?Why glass-based electrolytes?

• Preparation of lithium ion conducting glasses and glass-ceramics

• All-solid-state lithium secondary batteries using Li2S-based glass-ceramics

• Preparation of glassy electrode materials for all-solid-state lithium secondary batteries - A new concept of all-glass-based battery systems

• Conclusions

Introduction

Change of energy density of batteries Development of lithium ion battery market

number amount

Num

ber

Amou

nt / b

illion

yenLi-ion

Ni-HNi-Cd

Li-ion

Ni-H

Ni-Cd

Ener

gy d

ensit

y / W

h/L

5.2 x

during 15

years

Li-ion battery Japan

China

Korea

othersShare of battery in the worldDevelopment of the battery businessDevelopment of the battery business

The lithium ion secondary battery is very promising not only for miniaturized electric appliances but also as a large energy storage device for HEV and EV. The lithium ion secondary battery is very promising not only for miniaturized electric appliances but also as a large energy storage device for HEV and EV.

Development of miniaturized electric appliancesDevelopment of miniaturized electric appliances

All-solid-state lithium secondary battery system using non-flammable inorganic solid electrolytes

Ultimate goal of rechargeable energy sources

・ high safety・ high reliability・ high energy density

There are serious safety problems present in lithium ion secondary batteries using flammable organic liquid electrolytes.

Smart cardFilm battery ICAntenna EV

Studies on all-solid-state lithium secondary batteryThin-film battery Bulk-type battery

………. very promising for use in all-solid-state batteries

・ wide selection of compositions

・ isotropic properties・ no grain boundaries・ easy film formation・ nonflammability・ etc.

Inorganic glassy solid electrolytes

2. Single cation conduction is realized because glassy materials belong to the so-called “decoupled systems” in which the mode of ion conduction relaxation is decoupled from the mode of structural relaxation.

1. Ion conductivity is generally higher in glass than that in corresponding crystal due to the so-called “open structure.”

L i + L i +

L i +

L i +

L i +

L i + L i +

L i +

L i +

L i + L i + L i +

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 +

cathodeanodeC Co O2

Inorganic glassy electrolyte

all-solid-state battery

anodecathode

conventional battery

crystal glass

Inorganic glassy solid electrolytes

Ideal battery system with no side reactions

Large amounts of free volume

Inte

nsity

( arb

.uni

t) : α -AgIσ25 =10-1 Scm-1

3. Superionic coducting crystals as a metastable phase are easily formed from inorganic glassy electrolytes.

Inorganic glassy solid electrolytes

crystal

glass

liquid

supe

rcoole

d liquid

Volu

me

Temperature

Tg Tm

crystallization

Superionic phase74AgI･26(0.33Ag2O･0.67MoO4)

Tatsumisago et al., NATURE, 354 (1991) 217; Chem. Lett. (2001) 814.

Preparation of lithium ion conducting glasses and glass-ceramics

System

Li2S-SiS2

Li-P-O-N

Li2S-B2S3

Li4SiO4-Li3BO3

Li2S-P2S5

Li2S-GeS2

Li2S-SiS2-LiILi2S-P2S5-LiILi2S-SiS2-Li3PO4Li2S-SiS2-Li4SiO4

Li2O-Nb2O510-6

10-6

10-6

10-310-3

10-4

10-310-3

10-4

10-4

10-5

NassauTatsumisagoBates

Ribes

MaluganiLevasseur

Souquet

KennedyMaluganiKondoTatsumisago

σ25 / Scm-1 Researcher

Lithium Ion conducting glassy systems

Twin-roller quenchingTwin-roller quenchingSputtering

Twin-roller quenching

Melt quenchingMelt quenching

Melt quenching

Melt quenchingMelt quenchingMelt quenchingTwin-roller quenching

Procedure

High Li+ ion conduction in glass

・ Increase in Li+ ion concentration as much as possible・ Use of counter anions with high polarizability

10-6

10-5

10-4

10-3

10-2

10-1

100

1 1.5 2 2.5 3 3.5 4

Cond

uctiv

ity / S

cm-1

1000 / T (K-1)

Thio-LISICONLi3.25Ge0.25P0.75S4

PerovskiteLa0.51Li0.34TiO2.94

Li2O-Al2O3-TiO2-P2O5 (OHARA gc)glass-ceramic

Li2S-SiS2–P2S5-LiI glass

LISICON Li14Zn(GeO4)4

NASICONLi1.3Al0.3Ti1.7(PO4)3

Li3NLi3.4V0.4Ge0.6O4

Li2O-Nb2O5 glass

Li2O-B2O3-LiI glass

Li2S-SiS2 glassLi2S-SiS2-Li4SiO4 glass Li2S-P2S5glass-ceramics

σ25=3.2x10-3 Scm-1

Advanced Materials17 (2005) 918.

Temperature dependence of conductivity of a variety of high lithium ion conducting materials

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

・ Room temperature process・ Obtaining fine powders

directly

Mechanochemical synthesis

pulverizationchemical reactionMechanical energy

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Centrifugal force

Rotation of base disk

Rotation of pot

Ball

Planetary ball mill

Mechanochemical preparation of 95(0.6Li2S・0.4SiS2)・5Li4SiO4glass

2.0 2.5 3.0 3.5

Con

duct

i vit

y/ S

c m-1

10h,20h

5h

1h

0h

10-2

100

10-4

10-6

10-8

10-10

1000K / T

Melt quenched glass

95(0.6Li2S・0.4SiS2)・5Li4SiO

glass

10-8

10-6

10-4

10-2

100

1.8 2 2.2 2.4 2.6 2.8 3 3.2 3.4

Cond

uctiv

ity / S

cm-1

1000 K / T

Solid-state reaction

σ25 = 3.2 x 10-3 S/cm Ea = 12 kJ/mol

Heating at 360 ℃

Temperature dependence of conductivity for the 70Li2S・30P2S5 glass and glass-ceramic

σ25 = 5.4 x 10-5 S/cm Ea = 38 kJ/mol

New superionic metastable crystalline phase…….. could not be obtained by the usual solid state reaction.

1 0 1 5 2 0 2 5 3 0 3 5 4 0Int

ensit

y (ar

b.unit

)

2 θ / o (C u K α )

as-prepared360 oC

Solid-state reaction

: new phase

: thio-LISICON III

: Li4P2S6

: Li3PS4

The formation of superionic metastable phase is the most remarkable advantage of glass-based solid electrolytes.

All-solid-state lithium secondary batteries using Li2S-P2S5 glass-ceramics

Stainless steel

InsulatorPositive electrode

Li2S-P2S5 glass ceramics

Laboratory-scale all-solid-state cell

10mm

Solid electrolyte (SE)

Negative electrode

LiCoO2:SE:AB=20:30:3 (wt%) or

In orSnS-P2S5 glass: SE:AB

All-solid-state batteries（ In / Li2S-P2S5 glass-ceramic / LiCoO2 ）All-solid-state batteries（ In / Li2S-P2S5 glass-ceramic / LiCoO2 ）

Composite electrode is a mixture of three kinds of fine powders

Ionic and electronic conduction paths through SE and conducting additives to active materials

AB

LiCoO2

Solid electrolyte

Solid electrolyte

Current collector(S+CuS):SE:ABStainless steel

0

1

2

3

4

5

6

0 20 40 60 80 100 120

0 0.1 0.2 0.3 0.4x in Li1-xCoO2

Cell V

olta

ge / V

Capacity / mAh.g-1

64 μA.cm-2

15

20, 50

1520, 50Charge

Discharge

25 oC

Excellent cycle performance with no loss of capacity up to the cycle number of 500

In / 80Li2S・20P2S5 glass-ceramic / LiCoO2

Cell performance of the all-solid-state batteryCell performance of the all-solid-state battery

The advantage of the glass-ceramics with their high conductivity and dense microstructure would promote smooth charge-discharge reaction in the solid / solid interface between electrolyte and electrode.

0

50

100

150

200

020406080100120

0 100 200 300 400 500

Capa

city /

mAh

g-1

Effic

iency

/ %

Cycle number

: Charge capacity: Discharge capacity

0

1

2

3

4

5

6

0 20 40 60 80 100 120 140 160

Cell V

olta

ge /

V

Capacity / mAh g-1

100th Cycle64 μA cm -2

In/LiCoO2

In/LiNi0.5

Mn0.5

O2

In-Li/a-V2O

5

In-Li/Li4/3

Ti5/3

O4

All-solid-state cell performance using a variety of electrode active materialsAll-solid-state cell performance using a variety of electrode active materials

In or In-Li / 80Li2S・20P2S5 glass-ceramic / Cathode

All-solid-state batteries with high reversibility and high cycle performance

In / 80Li2S-20 P2S5 / LiCoO2 -xCoS

NaS2CN(C2H5) 2＋CoCl2 → Co[S2CN(C2H5)2]2

Co[S2CN(C2H5)2]2 → CoS

0.1 wt% coating

-800

-400

00 400 800 1200 1600 2000

-800

-400

0

Without coating

0.1 wt% coating

after 1st charge

after 1st charge

before

before

Z’/Ω

Z”/Ω

Z”/Ω

I = 10 mA cm-2 (10C)

0

1

2

3

4

5

6

0 20 40 60 80 100 120

Cell V

olta

ge / V

(vs.

In-L

i)

Capacity / mAh g-1

1st1st2nd2nd3rd3rd

1st1st2nd2nd

3rd3rd

0.1 wt% coating

For high rate performance ・Coating on active materials with cobalt sulfide

Preparation of glassy electrode materials for all-solid-state lithium secondary batteries - A new concept of all-glass-based battery systems -

Capacity (mAh g-1 of S+Cu)

0 400 800 120064 μA cm-2

0.3 - 2.7 V cutoff

1st

1st 2nd

2nd5th20th

10th

10th5th20th

0 200 400 600 800

Capacity (mAh g-1 of CuS)

Cell v

olta

ge (V

)

0

1

2

3

4

Cell performance of all-solid-state Li / S battery using Cu-S composites prepared by MM as a cathode material

In-Li / 80Li2S・20P2S5 glass-ceramic / Cu-S composite

Sulfur is utilized as active materials

650 mAhg-1(CuS) S, CuS composite3S + Cu MM

Sulfur cathode materials, which could not be used with liquid electrolytes, can be used in all-solid-state batteries using the sulfide glass-ceramic electrolytes.

After Machida (2002)

•Polysulfides formed in the discharge process are soluble in liquid electrolytes.

Theoretical capacity : 1672 mAh g-1Cheep, Non-toxic

Candidate of cathode materials for next-generation secondary batteries

Sulfur

0 200 400 600 800 1000 1200 1400

0 2 4 6 8 10

0

1

2

3

4

5

6

Capacity / mAhg-1

Cell v

olta

ge / V

Li / Sn

Discharge

Charge

15 2102050

5 2102050 1

Cutoff voltage : 2.0～4.0 V0

200

400

600

800

1000

1200

1400

0

20

40

60

80

100

0 10 20 30 40 50 C

apac

ity / m

Ahg-1 Efficiency / %

Cycle number

Cutoff voltage : 2.0～4.0 V

Discharge

Charge

Cell performance using SnS-P2S5 glasses as an anode material

80SnS・20P2S5 glass / 80Li2S・20P2S5 glass-ceramic / LiCoO2

400 mAhg-1

SnS-P2S5 glassesSnS + P2S5MMGlassy materials contining Sn

anode active material

Sn0 + Li+ + e- Li4.4Sn charge

discharge

SnS-P2S5 + Li+ + e- Sn0 + Li2S-P2S5charge Self-formation of high conductive

solid electrolytes surrounding the anode active materials

J.L. Souquet et al., Solid State Ionics, 148 (2002) 375.

A common network former is used for the electrolyte and electrode materials.

Glassy monolithic cellGlassy monolithic cell

The glassy monolithic cell is expected to facilitate smooth solid-solid contact between electrolyte and electrode, and very promising as a future all-solid-state battery.

Li2S-P2S5glass-ceramic

SnS-P2S5glassLi2S-Cu-S ceramic

Conclusions

CONCLUSIONSCONCLUSIONSCONCLUSIONSCONCLUSIONS

Sulfide glass-based solid electrolytes are suitable to be used in all-solid-state lithium secondary batteries.The all-solid-state batteries showed excellent cycle performance. In order to obtain high rate performance, electrons and ions should be smoothly supplied to the active materials through the interface between electrode and electrolyte .All-solid-state batteries, in which a common sulfide glass network is used as electrodes and electrolytes, are successfully constructed.

CONCLUSIONSCONCLUSIONS

In order to approach the ultimate goal of all-solid-state lithium secondary battery, the charge transfer at the solid/solid interface between electrolyte and electrode should be analyzed and optimized to obtain much higher performances.

Thin film battery

Electrode active material

Interface between electrode and electrolyte

Large scale battery

Solid electrolyte