6B.BKBN7 2 B¥B|BaB B BeB® 5 ð Ú ±B1 t1g. B+...

Hitachi Maxell Energy, Ltd. – Confidential and Proprietary August 29, 2011

SPring-8 5


6535 6540 6545 6550 6555 6560 65650.0

0.2

0.4

0.6

0.8

1.0

Abso

rban

ce

Energy / eV

LiMn2O4 Mn

Jahn-Teller (Mn3+)

LiMn2O4Mn

2Mn3+��2++Mn4+

Mg2+ Mn3+

Mn K-edge

LiMn2O4

LiMg0.02Mn1.98O4LiMg0.2Mn1.8O4

Mg2+ Mn K-edgeMn3+

Mn K-edge XANES Profiles of LiMgxMn2-xO4


SiOC

XANES TEM

SiO XRD

SiO Si SiO2SiO2 Si

1830 1840 1850 1860 1870

SiO2

SiO

Si

Abso

rban

ce

Photon Energy / eV

Si K-edge XANES Profiles of Si Materials

SiO2 matrices(amorphous)

Si (111) 2nm

Si Particle (3nm)

High Resolution TEM Image of SiO

Si ultra fine particles(


350

400

450

500

550

600

'12'11'08'06'04 '10'09'07'05

Ener

gy D

ensi

ty /

WhL

-1

Calendar Year'03

→

Calculate from prismatic cell


300 400 500 600 700 800 9003.3

3.4

3.5

3.6

3.7

3.8

3.9

4.0

4.1

Specific Discharge Capacity / mAhcc-1Dis

char

ge P

oten

tial /

V v

s Li

/Li+

0 500 1000 1500 2000 25001.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0.0

LiCoO2

L4Ti5O12

LiMn2O4

LiNi1/3Co1/3Mn1/3O2

LiFePO4

Graphite

LiNi0.8Co0.15Al0.05O2Li2.6Co0.4N

LiNiO2

LiVO2

CoSn Sn

SiOSi

Li

Cathode Materials Anode Materials


Ni 4.2 V Li 4.2 V

Voltage profiles calculated using electrochemical density of state( ) ( )

i

iii x

xFRTx

FExE

-1ln2-2-1z-0

φ=

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.02.8

3.2

3.6

4.0

4.4

4.8

5.2

x in LixMeO2

Pote

ntia

l /

V v

s. L

i/Li+

4.2

150 mAh g-1

High capacity

LiNiO2

LiCo3/4Ni1/4O2

LiCo1/4Ni3/4O2

LiCoO2

200 mAh g-1

T.Ohzuku and A.Ueda, J.Electrochem.Soc.,144, 2780(1997)


Ni 90% 4.2 V

LiCoxNi1-xO2 with x = ca.0.1 show the highest capacity

Ni/Co

1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.00

100

120

140

160

180

200

220Re

char

geab

le c

apac

ity /

mAh

g-1

x in LiCoxNi1-xO2


LiNiO2 Ni 90%

0 50 100 150 200 250

3

4

3

4

3

4

Capacity / mAh g-1

Pote

ntia

l /

V v

s. L

i/Li+

More than 200 mAh g-1 of rechargeable capacity

LiNi0.9Co0.1O2

LiNi0.8Co0.2O2

LiNiO2

Examined in lithium cell


LiNi0.9Co0.1O2

0 100 200 300 400 50050

60

70

80

90

100

110Ca

paci

ty re

tent

ion

/

%

Cycle number / -

Prismatic Cell (463443)

Nominal capacity : ca. 850 mAhCurrent : 0.7 C rate (charging), 1 C rate(discharging)Voltage ranges : 2.5 to 4.2 V (n=3)

LiNi0.9Co0.1O2 / Graphite

LiNi0.9Co0.1O2


LiNi0.9Co0.1O2

500

5002.5 V

DME

LIB

0 40 80 120 160 200 2402.0

2.5

3.0

3.5

4.0

4.5

Pote

ntia

l /

V v

s. L

i/Li+

Capacity / mAh g-1

LIB

Li

Li


LiNi0.9Co0.1O2 (TG, XRD)

10 20 30 40 50 60 70

LiNi0.9Co0.1O2

LiNi0.9Co0.1O2

a=2.8798 Åc=14.1435 Åc/a=4.911

a=2.8709 Åc=14.1530 Åc/a=4.930

I(003)/I(104)=1.22

I(003)/I(104)=0.97

(113

)(110

)(1

08)

(107

)

(105

)(1

04)

(102

)(006

)(101

)

(003

)

(CuKα)2θ / degree0 200 400 600 800 1000

5

4

3

2

1

0

Wei

ght l

oss

/

%

Temperature / oC

TG curves of LiNi0.9Co0.1O2 XRD patterns of LiNi0.9Co0.1O2

TG 800XRD 800 (900 ) I(003)/I(104) Li Ni

800Li Ni


LiNi0.9Co0.1O2 (XAFS)

8355 8360 8365 8370 8375

0.0

0.2

0.4

0.6

0.8

1.0

NiONi K-edge

Norm

aliz

ed a

bsor

banc

e /

-

Energy / eV

LiNi0.9Co0.1O2 LiNi0.9Co0.1O2 heated at 900

oC for 6h in air

0 1 2 3 4 50

4

8

12

16

20

Ni - Ni

Ni - O

FT in

tens

ity

/ -

R / Å

LiNi0.9Co0.1O2 LiNi0.9Co0.1O2 heated at 900

oC for 6h in air

rmal

i

@Spring-8(BL16B2)

Ni-O[ ] Ni-O[ ] Ni-O[ ]-Ni-O[ ] Ni-NiLiNi0.9Co0.1O2 1.922 Å 2.070 Å 0.148 Å 2.861 Å

LiNi0.9Co0.1O2 (heated at 900oC) 1.915 Å 2.049 Å 0.134 Å 2.873 Å

Ni-O[ ]

Ni-O[ ]

: O: Ni

Ni-O[ ]

Ni-O[ ]

: O: Ni

Ni K-edge XANES Profiles of Li 0.9Co0.1O2 FT of Ni K-edge spectra of Li 0.9Co0.1O2

Li Ni Ni2+


LiNi0.9Co0.1O2

Ni2+

Ni2+

Ni2+

Ni2+ 0 50 100 150 200 2502.5

3.0

3.5

4.0

2.5

3.0

3.5

4.0

4.5

LiNi0.9Co0.1O2

Pote

ntia

l /

V v

s. L

i/Li +

Capacity / mAh g-1

LiNi0.9Co0.1O2

XRD Li NiXAFS Ni2+


LiNi0.9Co0.1O2

Mg2+Mn4+

LiNi0.9Co0.05Mn0.025Mg0.025O2

Mn2O3

Li2MnO3

Mn K edge

6530 6540 6550 6560 6570

0.0

0.2

0.4

0.6

0.8

1.0

Norm

aliz

ed a

bsor

banc

e /

-

Energy / eV

�Ni : 90%�Co3+ Mn4++Mg2+ LiNi0.9Co0.05Mn0.025Mg0.025O2

Ni LiMn4+ Mg2+

(3+)

(4+)Ni2+

XANES Profiles of LiNi0.9Co0.05Mn0.025Mg0.025O2

LiNi0.9Co0.05Mn0.025Mg0.025O2 Mn 4


LiNi0.9Co0.1O2

0 100 200 300 400 50050

60

70

80

90

100

110

Capa

city

rete

ntio

n /

%

Cycle number / -

After charging at 4.2V in the cell with graphite

Heating rate; 2ºC/min

LiNi0.9Co0.1O2

LiNi0.9Co0.05Mn0.05O2LiNi0.9Co0.05Mn0.025Mg0.025O2

LiNi0.9Co0.1O2

LiNi0.9Co0.05Mn0.05O2

LiNi0.9Co0.05Mn0.025Mg0.025O2Prismatic Cell (463443)


5

6

7

8

9

10

11

Capa

city

rete

ntio

n /

%After charging at 4.2V in the cell with graphite

Heating rate; 2ºC/min

LiNi0.9Co0.1O2

LiNi0.9Co0.05Mn0.05O2LiNi0.9Co0.05Mn0.025Mg0.025O2

DSC Profiles Cycle ability

Mn, Mg60% 76%@500cycle


LiNi0.9Co0.1O2

10 20 30 40 50 60 70

(113

)(1

10)

(108

)

(107

)

(105

)(1

04)

(102

)(0

06)

(101

)

(003

)

(CuKα)2θ / degree8350 8360 8370 8380

0.0

0.2

0.4

0.6

0.8

1.0

Norm

alize

d ab

sorb

ance

/

-

Energy / eV

500XRD

@spring-8

: Li1.0Ni0.9Co0.1O2500 : Li0.6Ni0.9Co0.1O2-x

XAFS(TEY)

50040 nm

Ni

NiO-like ICP

Ni K edge

Ni ?


LiNi0.9Co0.1O2

0 100 200 300 400 50050

60

70

80

90

100

110Ca

paci

ty re

tent

ion

/

%

Cycle number / -

LiNi0.9Co0.1O2

LiNi0.9Co0.05Mn0.025Mg0.025O2

Prismatic Cell (463443)



SiOC


Si-C

Reducing a volumetric expansion of Li-Si anodematerial for Li insertion

Concept for Porous Composite Particle

Discharge Charge

Cycling

Coatings Carbon material

Si

Pore

To use fine Si powder To granulate fine Si and carbon with poreTo coat composites with carbon

Improving cycleability of Si anode

��

SEM Image of Porous Si-C Composite


10 20 30 40 50 600

10

20

30

40

50

60

Expa

nsio

n Ra

te o

f Dia

met

er /

%

Porosity / %

Si/G

raph

ite

Si/C

F

Si/C

F/P

BAfter 1st chargeby 1Ah/cc

After 1st discharge

Expansion Rate of Porous Si-C Composite for Cycle

0 10 20 30 40 500.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

Capa

city

/ Ah

g-1

Cycle Number

��(Porosity: 52vol%)

��Gr(Porosity: 30vol%)

Mixture Si and C

Graphite

Cycle Properties of Porous Si-C Composite

Si-C

50 ��Si


Si

0 5 10 15 20 25 30 35 40 45 500.0

0.2

0.4

0.6

0.8

1.0

1.2Ca

paci

ty /

mAh

Cycle Number

1000nm

300nm

100nm25nm

→ →→


CoatingsCarbon material

Pore

C bo eC eeAmorphous matrices (X)

Nano Si crystalline< 20nm

Nano-Si can show improved cycleability without crumbling.

Amorphous matrices can reduce the expansion rate for cycle.

Cycling

Nano Li-Si crystalline

Discharge Charge

Active particle(nano-Si/amorphous)

SiO

Si 2

→ → → →


1820 1830 1840 1850 1860 1870 1880

Abso

rban

ce

Photon Energy / eV

SiO2

Si

SiO

Si X XANES

SiO = Si + SiO2 X


20nm

Si (111)

2nm

Si: 3nm

SiO2 matrices(amorphous)

Si ultra fine particles(


0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.40.0

0.5

1.0

1.5

2.0Po

tent

ial /

V v

s Li

/Li+

Capacity / Ahg-1

1st Efficiency= 73%

1st Efficiency= 54%

SiO-C

SiO-C Composite

Mixture SiO and Gr

SiO C � 20%UP

��


0 20 40 60 80 10020

40

60

80

100

Capa

city

Ret

entio

n / %

Cycle Number

Positive electrode: LiCoO2+LiNi1/3Co1/3Mn1/3O2Current: 0.5CTemp.: 23

SiO-C Composite

Mixture SiOand Graphite

Si-C Composite

SiO C � %UP

SiO-C


(Assumption)SiO + 6.4Li ��4.4 + Li2O (irreversible phase)

(Theoretical Value)Charge Capacity = 3880mAh/g1st Efficiency = 68%

ExperimentalResults

Charge Capacity/ mAhg-1

Discharge Capacity / mAhg-1

1st Efficiency / %

(10mV 1.5V)

SiO-C Composite(per weight of SiO)

ggg

1200(2560)

ggg

872(1869)

73

Mixture SiO + Gr(per weight of SiO)

( )1382

(2570)

( )740

(1388)54

Inconsistency

SiO Li2O

Why does the first efficiency of SiO-Ccomposite increase ?


Discharge to 3V (Li/Li+)0.25mA/cm2 CC

(NMR: 2.5V CC)

FIB system in ArSTEM system in vac.using atmosphere blocking cellMeasuring in vac.

FFFFSSSSSSuuM

Si

Charge to 10mV (Li/Li+)0.25mA/cm2 CCCV

(until 0.025mA/cm2)

(NMR: 4.2V CCCV)

Li-Si-Omatrices

Extract the sample in Ar→ Wash with DEC→ Dry and transfer to …

XANES system in Arusing Ar flow bagMeasuring in vac.

NMR system in Arusing atmosphere blocking cellMeasuring in Ar

Charge

Discharge

Structural AnalysisCharge & Discharge

XANES and STEM-EELS→ Li cell

NMR→ Full cell

XXXXuuM

NNNNuuMDDii hh

Li-Si-Omatrices

LixSi

CCChhh

SiO2matrices

Si


80 60 40 20 0 -20 -40 -60 -80

Inte

nsity

Chemical Shift / ppm50 0 -50 -100 -150

Inte

nsity

Chemical Shift / ppm

SiO2/ LixSi

Si / Li2SiO3Li4SiO4

Li-Si-O

LixSi

29Si NMR spectra of SiOC 7Li NMR spectra of SiOC

Initial

Charge

Discharge

SiO NMRLi4SiO4


50nm 90 100 110 120 130 140 150

Inte

nsity

Energy / eV

EELS spectra of SiOC

( I )( II )

( I )

( II )Si4+

Si0

STEM image of SiOC (discharge state)

SiO STEM-EELS


Li4SiO4 Li4Si

Li4SiO4Li2SiO3

Li4SiO4

Li4SiO4

ChargeInitial

SiO2Si

Li4.4Si

LiSiO Li2SiO3

Si Discharge

Lithium ion conductor

SiO Li


2Si + 8.8Li ��4.4)2SiO2 + 8.4Li ��4.4 + Li4SiO4 (irreversible phase)

Causing an increase in Si sizeCausing a superior battery properties

SiO Li4SiO4

��

Charge Capacity (Qc) and First Efficiency (E1st) of SiO

Experimental Results Mixture SiO and C: Qc= 2560mAh/g(SiO) E1st= 54%SiO-C Composite: Qc= 2570mAh/g(SiO) E1st= 73%

Calculated Value (from Analysis)Reaction 4SiO + 17.2Li ��4.4) + Li4SiO4

Qc= 2610mAh/g E1st= 76.7%

GoodAgreement


LiNi0.9Co0.1O2 SiOC

LiNi0.9Co0.1O2 Ni2+ Li

LiNi0.9Co0.1O2

Mn MgLiNi0.9Co0.1O2

SiO Si SiO2 SiO2 Si

SiO Li-Silicate

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