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Development of Nanocomposite
Polymer Electrolytes (NCPEs) in
Electric Double Layer Capacitors
(EDLCs) Application
S. Ramesh
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UNIVERSITY OF MALAYA, MALAYSIA
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OVERVIEW
1) Introduction
2) Problem Statement
3) Literature Review
4) Methodology
5) Results and Discussion
6) Conclusions
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INTRODUCTION
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Light in
weight
Easy
handling
Thermally
stable
Safer
Flexible
Advantages
of Solid
Polymer
Electrolytes
Wider
electrochemical
stability
Applications of
Polymer Electrolytes
Lithium ion batteries
Sensors
Fuel cells
Solar cells
Supercapacitors
Electrochromic windows
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Low ionic conductivity
PROBLEM
STATEMENTS
Biopolymer
Ionic liquids
Environmentally
unfriendly
Polymer blending
Mixed salt system
Mixed solvent
system
Ionic liquids
Plasticizers
Fillers
Fillers
Polymer blending
Low mechanical
strength
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Starch
Natural
Cellulose
Chitosan
Biodegradable
polymer
PVA
Synthetic
PLA
PHA
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LITERATURE
REVIEW
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Excellent
tensile
strength
Environmentally
friendly
Non–
toxic
Excellent
charge storage
capacity
Good chemical
stability
Excellent
thermal
stability
High
dielectric
constant
Biocompatible
Advantages
of PVA
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Wider electrochemical potential
window
Non–toxic
Excellent
thermal
stability
Non–
flammable
Advantages of
Ionic Liquids
Superior
electrochemical
stability
High ion
content
Non–volatile
Plasticizing
effect
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Filler
Inorganic
Active
•
•
•
•
•
Lithium–nitrogen (Li2N)
Lithium aluminate (LiAlO2)
Lithium containing ceramics
Titanium carbides (TiCx)
Titanium carbonitrides (TiCxNy)
Organic
Passive
•
•
•
•
•
•
•
•
• Graphite fibre
• Aromatic polyamide
• Cellulosic rigid rods
(whiskers)
Inert metal oxide
Molecular sieves and zeolites
Ferroelectric materials
Rare earth oxide
Solid superacid
Carbon
Nano–clay
Heteropolyacid
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Advantages of Fillers
Enhance
interfacial
stability
Enhance
thermal
stability
Reduce Tg
Increase
cationic
diffusivity
Improve
physical
properties
Decrease the
crystallinity
Improve
morphological
properties
Lower
interfacial
resistance
Improve
long–term
stability
Reduce
water
retention
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Supercapacitors
Pseudo–capacitors
Redox
reaction
•Conducting polymers
•Metal oxide
Electric double
layer capacitors
(EDLCs)
Charge
accumulation
•Carbon
Hybrid
capacitors
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ELECTRIC DOUBLE LAYER
CAPACITORS (EDLCS)
Longer cycle life
Faster charge–
discharge rate
Higher power
density
Higher ability to be
charged and discharged
continuously without
degradation
Higher
capacitive
density
Inexpensive
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Disadvantages of AC
CNT
Hard diffusion
Limit the accessibility of charge carriers
High microporosity (pore dimension: <2nm)
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MATERIALS
MATERIAL
Poly (vinyl alcohol) (PVA)
1–butyl–3–methylimidazolium bromide
(BmImBr)
Silica (SiO2) (70nm)
Titania (TiO2) (40–50nm)
Zirconia (ZrO2) (<100nm)
Alumina (Al2O3) (<100nm)
Distilled water
ROLE
Polymer
Ionic liquid
Fillers
Solvent
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METHODOLOGY
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A) SAMPLE PREPARATION
PVA+ BmImBr+
SiO2/TiO2/ZrO2/Al2O3
Stir and heat at
80 °C
Cast on Petri dish
EIS
DSC
LSV
Al2O3
ZrO2
TiO2
SiO2
Formation of free standing polymer electrolyte
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B) ELECTRODE PREPARATION
Stir for
several
hours
80 wt.% of activated carbon
5 wt.% of carbon black
5 wt.% of carbon nanotubes (CNTs)
10 wt.% of poly(vinylidene fluoride)
(PVdF)
1–methyl–2–pyrrolidone solvent
Dip
coating
process
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C) EDLC FABRICATION &
CHARACTERIZATION
Configuration: electrode/polymer electrolyte/electrode
Figure 1: The fabricated EDLC using the highest conducting ionic liquid–added polymer electrolyte from each
system.
Cyclic Voltammetry (CV)
Galvanostatic Charge–Discharge (GCD)
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RESULTS AND
DISCUSSION
Ambient Temperature–Ionic
Conductivity Studies
(2.58±0.01)×10-4 S cm-1
-3.60
log [σ ( Scm-1 )]
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-3.80
-4.00
-4.20
-4.40
-4.60
Si system
(3.18±0.01)×10-5 S
0
2
4
6
8
10
Weight percent of SiO2 (wt. %)
Figure 2: The logarithm of ionic conductivity of polymer electrolyte at different mass fraction of (a) SiO2 and (b) ZrO2.
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Figure 3: The logarithm of ionic conductivity of polymer electrolyte at different mass fraction of (a) TiO2 and (b) Al2O3.
Temperature Dependent–Ionic
Conductivity Studies
-2.00
y = -0.6449x - 0.4834
R² = 0.9954
-2.50
log σ [(Scm-1)]
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-3.00
y = -0.7118x - 0.7307
R² = 0.9875
y = -0.721x - 0.7513
R² = 0.9863
-3.50
y = -1.0677x - 1.8396
R² = 0.9921
-4.00
-4.50
y = -1.3861x - 2.8442
R² = 0.9854
-5.00
2.5
2.6
2.7
Filler–free system
2.8
2.9
3
1000/T (K-1)
Si system
Zr system
3.1
3.2
Ti system
3.3
Al system
Figure 4: Arrhenius plot of filler–free polymer electrolyte and filler–doped NCPEs.
3.4
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Sample
Activation energy,
Ea (eV)
0.2751
–2.8442
Pre–exponential
constant, A
1.43×10-3
0.2119
–1.8396
0.0145
Zr system
0.1431
–0.7513
0.18
Ti system
0.1413
–0.7307
0.19
Al system
0.1280
–0.4834
0.33
Filler–free
system
Si system
Log A
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Differential Scanning Calorimetry (DSC)
Tg
9.06 °C
Exo
Heat Flow (W/g)
12.15 °C
14.11 °C
16.32 °C
18.12 °C
Endo
-20 -15 -10 -5 0
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90
Temperature(°C)
Si system
Zr system
Ti system
Al system
Filler–free system
Figure 5: Glass transition temperature (Tg) of polymer electrolytes.
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Tm
Figure 6: Crystalline melting temperature (Tm) of polymer electrolytes.
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Tc
H m
Xc 
 100%

H m
Heat of
Fusion
(Jg-1)
719.7
Relative
crystallinity
(%)
100
358.7
50
Zr system
287.6
0.40
Ti system
217.1
0.30
Al system
203.3
0.28
Filler–free
system
Si system
Figure 7 : Crystallization temperature (Tc) of polymer electrolytes.
Linear Sweep Voltammetry (LSV)
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1.2 V
2.2 V
Si system
Filler–free system
2.0 V
2.3 V
Zr system
2.2 V
Ti system
Figure 8: LSV response of the most conducting polymer electrolyte from each system.
Al system
Cyclic Voltammetry (CV)
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Filler–free system
i
C sp 
sm
0.15 F g-1
1.74 mF cm-2
i
C sp 
sA
(a)
Figure 9: Cyclic voltammogram of EDCL containing the most conducting polymer electrolyte from (a) filler–free system and (b)
Si system.
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Figure 10: Cyclic voltammogram of EDCL containing the most conducting polymer electrolyte from (a) Zr system, (b) Ti system
and (c) Al system.
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Galvanostatic Charge–Discharge Analysis
(GCD)
Csp 
Si system
(a)
I
m dV

dt
Csp  dV 

2
E
2

(b)
1000
3600
I  dV
P
 1000
2 m

td
 100
tc
Figure 11: Galvanostatic charge–discharge performances of EDLC containing (a) Si system and (b) Zr system over first 5 cycles.
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Ti system
4.34 F g-1
(a)
Al system
8.62 F g-1
(b)
Figure 12: Galvanostatic charge–discharge performances of EDLC containing (a) Ti system and (b) Al system over first 5 cycles.
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System
Specific discharge Coulombic
Energy
capacitance, Csp efficiency, η density, E
(F g-1)
(%)
(W h kg-1)
Si system
2.58
86
0.18
Power
density, P
(W kg-1)
34.94
Zr system
4.16
40
0.36
36.76
Ti system
Al system
4.34
8.62
76
81
0.42
0.95
38.41
41.15
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CONCLUSIONS
• Addition of nano–sized fillers
Increases the ionic conductivity
Follows Arrhenius rules for the conduction mechanism
Reduces the Tg and crystallinity
Improves the electrochemical stability window
Enhances the electrochemical properties of EDLCs
(i.e. capacitance)
• Alumina–based polymer electrolyte is a good choice as
separator in EDLC
Supervision
Dr. Yugal
Kishor
Mahipal
Mr. Mohd
Zieauddin bin
Kufian
Miss Liew
Chiam Wen
Madam
Rajammal
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Madam Lim
Jing Yi
Miss Shanti
Rajantharan
Mr. Ramis Rao
Mr.
Mohammad
Hassan
Khanmirzaei
Mr. Lu Soon
Chien
Mr. Vikneswaran Mr. Ng Hon Ming
Rajamuthy
Miss Chong
Mee Yoke
Miss Nurul
Nadiah
WELCOME TO MALAYSIA
Alumina–based polymer electrolyte
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