정보통신소재연구센타 center for information and communication materials ki hong min, dong...

정보통신소재연구센타정보통신소재연구센타Center for Information and Communication Materials Center for Information and Communication Materials

Ki Hong Min, Dong Hack Suh*

* Department of Chemical Engineering Hanyang University

Information & Communication Materials LabE-mail : [email protected]

Tel : 82-2-2290-0523 Fax : 82-2-2282-0523

신규 고체형 고분자 전해질 개발에 관한 연구


E-2 세부과제 : 신규 Solid type 고분자 전해질 개발에 관한 연구

1 차년도(2000. 8 ~ 2001. 7)

신규 고분자 전해질 분자설계 및 합성

2 차년도(2001. 8 ~ 2002. 7)

신규 겔형 유 무기물 ․혼합조성

고분자 전해질 합성

3 차년도(2002. 8 ~ 2003. 7)

신규 고체형 유 무기물 ․혼합조성

고분자 전해질 합성

고이온전도도 Polymer/Solid Hybrid electrolyte

최종목표

•고분자 전해질의 열적 , 기계적 물성 향상 .• 이온 전도도 향상• 고 이온 전도도를 가지며 실제 사용 가능한 고체고분자 전해질 개발 .


4 차년도 목표

- Polymer/Solid Hybrid electrolyte 시제품

Polymer/Solid Hybrid electrolyte 최적화 평가 ‧계면특성 ( 접착력 ) 향상 연구 ‧전기적 특성향상 ( 고이온전도도 ) ‧신규 전해질 내에서의 리튬 양이온 수율 연구

Details


Molecular Design

• High ionic conductivity : high flexibility and solubility of lithium salt

• Good mechanical stability : introducing the PEGDMA matrix

* m and n are the repeating unit of poly(siloxane-g-alkylcyanide) and poly(ethylene glycol), respectivly.

PEGDMA

Polymer matrix

Good salt solvation polymer

Si O Si O Si

CH3

CH3

CH3 CH3

CH3

C

mCH3H3C

N

O

O

CH2CH2O

O

n+

Si O Si O Si

CH3 CH3

mO Si CH3H3C

n

C OCH2CH2N OCH33D4V4CT-m, n*

Acetonirile Group - High Solubility :• High Dielectric Constant() : 38.8


Preparation of monomers

O

SiO Si

O

SiOSi

CH3

H3C CH3

CH3 OCH2CH2

OCH2CH2

H2CH2CO

H2CH2CO

H3CO

OCH3

OCH3H3CO

3

3

33

D4TEG

O

SiO Si

O

SiOSi

CH3H

H3C

H

H

CH3

CH3

H

OO

CH3 +Pt(0), Toluene

3

D4CN

CN + O

SiO Si

O

SiOSi

CH3H

H3C

H

H

CH3

CH3

H

Pt(0), TolueneO

SiO Si

O

SiOSi

CH3

H3C CH3

CH3 CN

CN

NC

NC


Synthesis of polymer electrolyte

• Polysiloxane containing both alkyl cyanide and oligo(ethylene oxide)

+ +

D4CN D4TEG V4

Si O Si O Si

CH3 CH3

mO Si CH3H3C

n

C OCH2CH2N OCH33

H3C Si O Si CH3O

SiO Si

O

SiOSi

CH3

H3C CH3

CH3 OCH2CH2

OCH2CH2

H2CH2CO

H2CH2CO

H3CO

OCH3

OCH3H3CO

3

3

33

O

SiO Si

O

SiOSi

CH3

H3C CH3

CH3 CN

CN

NC

NC

Ground KOH

• Poly(siloxane-g-alkylcyanide)

O

SiO Si

O

SiOSi

CH3

H3C CH3

CH3 CN

CN

NC

NC

H3C Si O Si CH3

CH3

CH3

CH3

CH3

H3C Si

CH3

CH3

O Si O Si CH3

CH3

CH3

CH3

C N

nGround KOH

+

M2


Preparation of polymer electrolyte using the PEO matrix

Synthesis of polysiloxaneSynthesis of polysiloxane

Casting on the ITO-coated glassCasting on the ITO-coated glass

Mixing polysiloxane with PEGDMAMixing polysiloxane with PEGDMA

Vacuum dryVacuum dry

Measurement of ionic conductivityMeasurement of ionic conductivity

UV-irradiation crosslinkingUV-irradiation crosslinking

D4M2CN PEGDMA Sample

1 1 PD4M2CN-1.1

2 1 PD4M2CN-2.1

1 2 PD4M2CN-1.2

3 1 PD4M2CN-3.1


H3C Si

CH3

CH3

O Si O Si CH3

CH3

CH3

CH3

C N

n

2

3

4

1

5

1H-NMR Spectrum of D4M2CN

CDCl3

34

5

TMS

1, 2

-reaction


Ionic conductivity Results(1)

•Ionic Conductivities of D4V4CT-m,n at 20oC

Mole Ratio

{[CN]+[EO]}/[Li+]

Ionic Conductivities (S/cm)

D4V4CT-1.1 D4V4CT-1.2 D4V4-2.1

12 8.51 10-6 3.22 10-7 2.25 10-6

16 6.40 10-6 7.95 10-6 6.31 10-6

20 4.71 10-6 1.15 10-5 7.64 10-6

24 9.41 10-6 8.59 10-6 1.03 10-5

•Maximum Ionic Conductivities of D4V4CT-m,n at 60oC

Mole Ratio Ionic Conductivities (S/cm)

D4V4CT-1,1 24 9.4 10-5

D4V4CT-1,2 20 1.0 10-4

D4V4CT-2,1 24 8.8 10-5


Ionic conductivity Results(2)

•Ionic Conductivities Depending on Temperature

- 5.2E+00

- 5.0E+00

- 4.8E+00

- 4.6E+00

- 4.4E+00

- 4.2E+00

- 4.0E+00

- 3.8E+00

- 3.6E+00

2.70 2.90 3.10 3.30 3.50

d4v4ct- 1.1_24d4v4ct- 1.2_20d4v4ct- 2.1_24

Log

(

S/c

m)

1000/T (K-1)


Ionic conductivity of D4M2CN

•Ionic conductivities of D4M2CN at 30oC

Sample[CN]+[EO]/[Li+]

ratioConductivity

PD4M2CN-1,1

8 8.3 X 10-6

16 2.0 X 10-6

24 2.5 X 10-7

PD4M2CN-2,1

8 1.7 X 10-5

16 9.4 X 10-6

24 4.3 X 10-6

PD4M2CN-1,2

8 1.4 X 10-6

16 1.3 X 10-6

24 8.7 X 10-7

The polymer electrolyte film

Matrix : PEGDMA

Polymer : D4M2CN

Lithium salt


Properties of PD4M2CN-m,n

Ionic conductivity of PD4M2CN-2,1 depending on the concentration of salt

0 5 10 15 20 25-6.0

-5.8

-5.6

-5.4

-5.2

-5.0

-4.8

-4.6

Ion

ic c

on

du

ctiv

ity()

(S/c

m)

Concentration of salt

0 50000 100000 1500000

20000

40000

60000

80000

100000

Z'',

Oh

ms

Z', Ohms

Impedance spectroscopy measurement

Rb

-80 -60 -40 -20 0 20 40 60 80 100 120

-1.4

-1.2

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

Hea

t fl

ow

(W

/g)

Temperature(oC)

-42.7oC

-52.5oC

Sing glass transition temperatureA misicible polymer blends exhibit a single glass transition between two components

The most commonly used method for estabilishing miscibility in polymer-polymer blends or partial phase mixing


Molecular Design

AdventagesAdventages

Low TLow Tgg

Flexible of polymer chainFlexible of polymer chain

Chemical and electrochemical StabilityChemical and electrochemical Stability

High ionic Conductivity : 10High ionic Conductivity : 10-3-3 S/cm at RT S/cm at RT

Improved mechanical stabilityImproved mechanical stability

Thermal StabilityThermal Stability

EC/PC Li Salt( ) ( ) ( )

+ + Li+ Anion-EC/PC

Heat(100Heat(100℃℃))20min20min

AIBN((Azobis(isobutyronitrile)) AIBN((Azobis(isobutyronitrile))

O Si

OO

O

CH3

CH3

(Si

CH3

(OCH2CH2)3OCH3

O

O Si

CH3

CH3

O)20

O

OO

OO

Poly(siloxane-g-oligo(ethylene oxide)) tetra acrylate

*PS-(g-EO)TA


Synthesis of cross-linkerSynthesis of cross-linker

Si O SiOO O O

OO

CH3

CH3 CH3

CH3O

O O

O

Si OOO

O

CH3

CH3

O

O

Si O Si O O

OCH3

CH3

O

OCH3

(OCH2CH2)yOCH3

x

SiO

OSi

OSiO

Si

(OCH2CH2)nOCH3CH3

(OCH2CH2)nOCH3

CH3

CH3O(CH2CH2O)n

CH3

CH3O(CH2CH2O)n

CH3

Fumming Sulfuric Acid

＋

D4-TEG PS-(g-EO)TA

D4-TEG

n=3D2-TA

PS-(g-EO)TA

Mn D.P

1H- NMR* 5900 20

GPC** 4365 14

*end-group analysis**polystyrene standard


PS-[g-EO]TA (X=20, Y=3)PS-[g-EO]TA (X=20, Y=3)

4.00

00

3.88

52

3.95

70

1.84

98

4.74

41

213.

38

28.0

59

27.1

70

52.2

44

Inte

gral

(ppm)

0.01.02.03.04.05.06.0

a, a’

b, b’c, c’

d, d’, g

f

e

ihl, l’

k, k’

l, l’

11H- NMRH- NMR

Si OOO

O

CH3

CH3

O

O

Si O Si O O

OCH3

CH3

O

OCH3

(OCH2CH2)3OCH3

10

a a'

b

b'

c

c'

d

d'

e f

g h i

jk

l

j'k'

l'

20


DSC thermolgram of GPEDSC thermolgram of GPE

• Cross-linker : Poly(siloxane-Cross-linker : Poly(siloxane-gg-ethylene oxide)TA -ethylene oxide)TA

• Lithium salt : 1M LiPFLithium salt : 1M LiPF66

• plasticizer : EC + PC (1:1)plasticizer : EC + PC (1:1)

-150 -100 -50 0 50

-6

-5

-4

-3

-2

-1

0

1

2

3

4

Hea

t Flo

w (W

/g) (a

.u.)

Temperature( )℃

Pure cross-linker EC/PC 30wt% (1M LiPF

6)

EC/PC 50wt% (1M LiPF6)



℃

Tg

EC+PC

Content

Tg of polymer

electrolyte( )℃

0 wt% -77.53

30 wt% -80.09

50 wt% -86.66

60 wt% -93.14

70 wt% -97.33


Ionic conductivityIonic conductivity

Effects on the EC/PC contents

30 40 50 60 70

10-3

10-2

30℃ 60℃ 90℃

EC/PC Content (weight %)

Con

duct

ivity

(S/c

m)

-100

-98

-96

-94

-92

-90

-88

-86

-84

-82

-80

-78

Tg(

)℃

℃℃℃

℃

2.6 2.7 2.8 2.9 3.0 3.1 3.2 3.3

10-3

10-2

Con

duct

ivity

(S/c

m)

1000/T(K)

EC/PC 30% EC/PC 50% EC/PC 60% EC/PC 70%

Temperature Dependence


VTF Plot of GPEVTF Plot of GPE

VTF(Vogel-Tamman-Fulcher) Equation

))(

exp(0

2/1

TTR

EAT

a

*T0 = Tg - 50

A : No. of Charge carrier

Ea : Pseudo-activation energy

R : Gas constant

T0 : Reference temperature

4.0x10-3 4.5x10-3 5.0x10-3 5.5x10-3 6.0x10-3 6.5x10-3

-4.5

-4.0

-3.5

-3.0

-2.5

-2.0

-1.5

-1.0

ln(σ

T1/2 )

1 / (T-T0) (K)

EC/PC 30% EC/PC 50% EC/PC 60% EC/PC 70%


Potential Window of GPEPotential Window of GPE

-1 0 1 2 3 4 5

-1.0x10-3

-5.0x10-4

0.0

5.0x10-4

1.0x10-3

1.5x10-3

2.0x10-3

Cu

rren

t (A

)

Voltage (V vs Li)

EC/PC70wt% EC/PC60wt% EC/PC50wt%

• Cross-linker : Poly(siloxane-Cross-linker : Poly(siloxane-gg-ethylene oxide)TA -ethylene oxide)TA • Lithium salt : 1M LiPFLithium salt : 1M LiPF66

• plasticizer : EC + PC (1:1)plasticizer : EC + PC (1:1)• Li/GPE/Ni cell at 3030oC• Scan rate : 10mV/s


Lithium Plating/StrippingLithium Plating/Stripping

Coulombic Efficiency(%)

= 100QS

QP

QS = stripping charge

QP = plating charge

Cyclic VoltammetryCyclic Voltammetry

-600 -400 -200 0 200 400 600 800

-2.0x10-4

-1.5x10-4

-1.0x10-4

-5.0x10-5

0.0

5.0x10-5

1.0x10-4

1.5x10-4

Cu

rren

t (A

)

Voltage (mV)

EC/PC 50%

0 5 10 15 20 25 300

20

40

60

80

100

Cyc

le e

ffic

ienc

y (%

)

Cycle number

TA20 (EC/PC 50%) TA20 (EC/PC 60%)

• Cross-linker : Poly(siloxane-g-ethylene oxide)TA • Lithium salt : 1M LiPF6

• plasticizer : EC + PC (1:1)• Li/GPE/Ni cell at 30oC• Scan rate : 10mV/s

-600 -400 -200 0 200 400 600 800-4.0x10-4

-3.0x10-4

-2.0x10-4

-1.0x10-4

0.0

1.0x10-4

2.0x10-4

3.0x10-4

Cu

rren

t (A

)

Voltage (mV)

EC/PC 60%


Discharge rate (C-rate)Discharge rate (C-rate)

Cross-linker (PS-(g-EO)TA) : liquid electrolyte (EC+PC in 1M LiPF6) = 10 : 90 wt%

+ AIBN (5 wt% to the weight of cross-linker),

0 10 20 30 40 502.6

2.8

3.0

3.2

3.4

3.6

3.8

4.0

4.2

Vol

atge

(V

)

Capacity (mAh)

(0.1C) (0.2C) (0.5C) (1C) (2C)

C- rateC- rate Li | GPE | LiCoO2

Discharge rate : 0.1C, 0.2C, 0.5C, 1C

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.20

10

20

30

40

50

60

70

80

90

100

Dis

char

ge c

apac

ity (

% )

Discharge rate ( C - rate)


4 6 8 10 12 14

1.0x10-5

2.0x10-5

3.0x10-5

4.0x10-5

5.0x10-5

6.0x10-5

(b)

(a)

SiO2[R812] weight percent ( % )

Ion

ic C

on

du

ctiv

ity

( S

/ cm

)

(a) PEO+LiBETI+D4CN-20wt+R812 (b) PEO+LiBETI+R812

(3-cyanopropyl)methylsiloxane cyclics (3-cyanopropyl)methylsiloxane cyclics 과 과 fillerfiller 의 첨가에 의한 제조되어진 고체 고분자 전해질의 첨가에 의한 제조되어진 고체 고분자 전해질

R812(silica powder)

D4CN

LiN(SO2CF2CF3)2

PEO


On going workSynthesis of D4PC

+O O

O

O

O

Si

O Si

O

Si

OSiH3C

H

CH3

H

CH3

H

H3C

H

Pt(0)

O

SiO Si

O

SiOSi

H3C

H3C

CH3

CH3

OO

O O

O

O

O

O

OO

O

O

O

O

O

O

Synthesis of D4DICN

OSi

OSi O

Si

OSi

CH3

CH3

H3C

H3CH H

HHO O

O

CN

CN

+O

HSi

OSi O

Si

OSi

O

O

O

CN

NC

H3C

O

O

O

CN

CN

CH3

O

O O

CNCN

CH3

O

OO

CN

CN

PT(0)

toluene


• Polysiloxanes comb-branched with allyl cyanide groups was synthesized for the siloxane-based polymer electrolyte.

• The crosslinkable prepolymers were easily crosslinked by UV irradiation and free standing fim can be prepared.

• Polysiloxane, D4V4CT-1.2, Showed More Improved Ionic conductivity, 1.1510-5 S/cm, than D4D2-n in the same Degree of Polymerization(DP=20) at 20 oC

• Polysiloxane, D4M2CN-2.1, showed maximum ionic conductivity, 1.710-5 S/cm at 20 oC

• The D4V4CT-1.2 was stable electrochemically in the range from +1.8 - +3.5V, the practical working range for practical secondary lithium battery

Conclusions


ConclusionsConclusions

Gel-type polymer electrolyte was prepared by using poly(siloxane-g-oligo

(ethyleneoxide)) (n=20) as a cross- linker.

Free standing film was obtained (up to 70wt% of liquid electrolyte )

Maximum conductivity of gel polymer electrolyte was measured to be

3.92×10-3 S/cm at 30 .℃ (70wt% of 1M LiPF6 in EC/PC).

Temperature dependence of conductivity followed VTF characteristics in the

temperature range of 30 100 . ∼ ℃Electrochemical stability was extended to 4.5V.

Reversible electrochemical plating/stripping of lithium is observed.

Battery performance was studied.

- The discharge capacity is measured to be 94% at 0.2C, 82% at 0.5C,

64% at 1C, 26% at 2C when Li-metal is used as an anode.

- Studies to improve the battery performance is being under taken.

The conductivity, electrochemical property and battery performance are investigated

with cross-linked polysiloxane-g-PEO gel polymer electrolyte


1 단계 : 신규 Solid type 전해질 소재 개발연구

목표 연구 내용 연구성과 성취율

1 차 년도(2000. 8 ~

2001. 7)

신규 고분자 전해질

합성

•신 규 고 분 자 전 해 질 분자설계 및 합성 . •기 존 전 해 질 조 성 및 특성평가 연구 . •신 규 고 분 자 전 해 질 합성연구 . •전해질 최적 조성비 연구 .

•특허맵 작성 •polyepoxytetrahydrofuran 의 합성 •vinyl ethylene carbonate 을 측쇄로 가지는 polysiloxane 의 합성•carbonate 와 maleic anhydride 의 공중합체 고분자 합성

80 %

2 차 년도(2001. 8 ~

2002. 7)

신규 겔형 유‧무기물

혼합조성 고분자 전해질

합성

• 신규 겔형 유‧무기 물 혼합소재 분자 설 계 및 합성 . •신 규 겔 형 유 ‧ 무 기 물 혼합소재 합성연구 . •상용성 및 상호특성 개선 연구 .

‧Alkyl cyanide 를 측쇄로 가지는 polysiloxane 의 합성

80%

3 차 년도(2002. 7 ~

2003. 8)

신규 고체형 유‧무기물

혼합조성 고분자 전해질

합성

• 신 규 고 체 형 고 분 자 전해질 분자설계 및 합성 .• 신규 고체형 유‧무 기물 혼합소재 합성 연 구 .‧ 신규 전해질의 기초 물성 연구 .‧ 전기적 특성분석 연구 .

‧Ethylene oxide 와 Alkyl cyanide 를 측쇄로 가지는 comb- branched polysiloxane 의 합성

87%

O Si

O

O

CH3

CH3

Si O Si

CH3

O

OCH3

CH3n

CN


학술지 (2002. 7. ~ 현재 , 센터 사사 , SCI)

1 단계 연구 성과물

Yong Ku Kang, Won Sil Lee, and Dong Hack Suh, and Chang Jin Lee, "Solid polymer electrolytes based on cross linked polysiloxane-g-oligo(ethylene oxide) : Ionic conductivity and electrochemical properties", Journal of Power Source, 119-121. 448-453 (2003)

Young Sik Lee, Gi Sang Song, Yong Gu Kang, and Dong Hack Suh, "The solid polymer electrolyte based on polysiloxanes containing alkyl cyanides and oligo polyethylene oxide pendants", Electrochemica acta, submitted, (2003).

Jun Kyoung Lee, Yong Ku Kang, and Dong Hack Suh, and Chang Jin Lee, "A study on ionic conductivity and electrochemical propreties of cross-linked siloxane-g-oligo(ethylene oxide) gel-type polymer electrolyte", Electrochemica acta, submitted, 2003.

특허 (2002. 7. ~ 현재 , 출원 및 등록 일자 기준 )

극성 시아나이드기가 측쇄형으로 된 고체형 고분자 전해질용 폴리실록산 및 그 제조법

서동학 , 이인재 , 송기상 , 이원실 , 이영식 . 출원번호 : 10-2002-0033842

학술지 (2002. 7. ~ 현재 , 센터관련 , SCI)

In Jai Lee, Gi Sang Lee, Won Sil Lee. and Dong Hack Suh, "A new class of the solid polymer electrolyte : synthesis and ionic conductivity of novel polysiloxane containing allyl cyanide groups", Journal of Power Sources, 114(2), 320-329 (2002)


Yongku Kang, Junkyung Lee, Wonsil Lee, Dong Hack Suh and Chanjin Lee, "Poly- (siloxane-g-oligo(ethylene oxide) acrylate : a Novel cross-linker for solid polymer electrolytes", The 5th Korea-Japan Joint Seminar on Advanced Batteris, Seoul, Korea, 2003. 09. 26 (2003),

Young Sik Lee, Gi Sang Song, Yong Gu Kang, and Dong Hack Suh, "The solid polymer electrolyte based on polysiloxanes containing alkyl cyanides and oligo polyethylene oxide pendants", 1st International conference on Polymer Batteries and Fuel Cells. Jeju island, Korea, 2003. 06. 02 (2003), Sponsor : Korean Electrochemical Society

Jun Kyoung Lee, Yong Ku Kang, and Dong Hack Suh, and Chang Jin Lee, "A study on ionic conductivity and electrochemical propreties of cross-linked siloxane-g-oligo(ethylene oxide) gel-type polymer electrolyte", 1st International conference on Polymer Batteries and Fuel Cells". Jeju island, Korea, 2003. 06. 02 (2003), Sponsor : Korean Electrochemical Society

Gi Sang Song, In Jai Lee, Won Sil Lee, and Dong Hack Suh, " A new class of the solid polymer electrolyte : Synthesis and ionic conductivity of novel polysiloxane containing allyl cyanide groups ", the 224th National Meeting and Exposition of the American Chemical Society, Boston , USA, 2002. 08. 20. (2002), Sponsor : Division of Polymer Chemistry, Inc.

국제학술 발표 (2002. 7. ~ 현재 , 출원 및 등록 일자 기준 )

정보통신소재연구센타 center for information and communication materials ki hong min, dong...

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