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
정보통신소재연구센타정보통신소재연구센타Center for Information and Communication Materials Center for Information and Communication Materials
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 .
정보통신소재연구센타정보통신소재연구센타Center for Information and Communication Materials Center for Information and Communication Materials
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
정보통신소재연구센타정보통신소재연구센타Center for Information and Communication Materials Center for Information and Communication Materials
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
정보통신소재연구센타정보통신소재연구센타Center for Information and Communication Materials Center for Information and Communication Materials
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
정보통신소재연구센타정보통신소재연구센타Center for Information and Communication Materials Center for Information and Communication Materials
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
정보통신소재연구센타정보통신소재연구센타Center for Information and Communication Materials Center for Information and Communication Materials
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
정보통신소재연구센타정보통신소재연구센타Center for Information and Communication Materials Center for Information and Communication Materials
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
정보통신소재연구센타정보통신소재연구센타Center for Information and Communication Materials Center for Information and Communication Materials
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
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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)
정보통신소재연구센타정보통신소재연구센타Center for Information and Communication Materials Center for Information and Communication Materials
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
정보통신소재연구센타정보통신소재연구센타Center for Information and Communication Materials Center for Information and Communication Materials
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
정보통신소재연구센타정보통신소재연구센타Center for Information and Communication Materials Center for Information and Communication Materials
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
정보통신소재연구센타정보통신소재연구센타Center for Information and Communication Materials Center for Information and Communication Materials
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
정보통신소재연구센타정보통신소재연구센타Center for Information and Communication Materials Center for Information and Communication Materials
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
정보통신소재연구센타정보통신소재연구센타Center for Information and Communication Materials Center for Information and Communication Materials
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)
EC/PC 60wt% (1M LiPF6)
EC/PC 70wt% (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
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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
정보통신소재연구센타정보통신소재연구센타Center for Information and Communication Materials Center for Information and Communication Materials
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%
정보통신소재연구센타정보통신소재연구센타Center for Information and Communication Materials Center for Information and Communication Materials
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
정보통신소재연구센타정보통신소재연구센타Center for Information and Communication Materials Center for Information and Communication Materials
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%
정보통신소재연구센타정보통신소재연구센타Center for Information and Communication Materials Center for Information and Communication Materials
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)
정보통신소재연구센타정보통신소재연구센타Center for Information and Communication Materials Center for Information and Communication Materials
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
정보통신소재연구센타정보통신소재연구센타Center for Information and Communication Materials Center for Information and Communication Materials
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
정보통신소재연구센타정보통신소재연구센타Center for Information and Communication Materials Center for Information and Communication Materials
• 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
정보통신소재연구센타정보통신소재연구센타Center for Information and Communication Materials Center for Information and Communication Materials
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
정보통신소재연구센타정보통신소재연구센타Center for Information and Communication Materials Center for Information and Communication Materials
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
정보통신소재연구센타정보통신소재연구센타Center for Information and Communication Materials Center for Information and Communication Materials
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)
정보통신소재연구센타정보통신소재연구센타Center for Information and Communication Materials Center for Information and Communication Materials
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 )