Download - Electrochemical Supercapacitors in F.E.E
Electrochemical
Supercapacitors in
F.E.E.Lab
Keryn Lian
Department of Materials Science and Engineering
University of Toronto
416-978-8631
Supercapacitors and Applications
エネルギーストレージシステム
1E+00
1E+01
1E+02
1E+03
1E+04
1E+05
1E+06
0.01 0.1 1 10 100 1000
Energy Density (Wh/kg)
Po
wer
Den
sit
y (
W/k
g)
Ultracapacitors
Capacitors
Batteries Fuel cells
Electrodes
Electrolyte/
separator
2 John R. Miller and Andrew F. Burke, The Electrochemical Society Interface. Spring 2008.
From Prof. K. Noai US DOE workshop
From Maxwell Web
1. Modification of Carbon electrodes
1. Activated Carbon, CNT, graphite nano-fibers and onion-like carbon characterization and chemical modification (Prof. Gogotsi, Drexel )
2. Direct formation of TiNx
Efforts on Electrochemical Capacitor (EC)
2. Solid Polymer
Electrolytes
1. Solid proton
conducting
electrolytes for thin,
flexible devices
2. Ionic liquid/polymer
for high voltage
window.
3. Hybrid Device &System
1. Super thin and flexible symmetrical and asymmetrical EC cells
2. ANN battery and hybrid cycle life prediction (Prof. Weigert, MST)
3. Simulation of devices life and thermal properties (Prof. Dawson, ECE, UT)
4. Hybrid EC with battery, photovoltaic for “self-power” and for extending power/energy efficiency (Prof. Kherani, ECE, UT).
Load
Solar Cell
Battery Electrochemical
Capacitor
(EC)
3
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New Advances in Proton Conducting Polymer
Electrolytes and their Applications in Ultrahigh
Rate Solid Electrochemical Capacitors
Keryn Lian
Department of Materials Science and Engineering
University of Toronto
416-978-8631
5
Outline
• Background – Ultra-high-rate Solid Electrochemical Capacitors (EC)
– Heteropolyacid (HPA) as proton conducting electrolytes
• Solid Proton Conducting Polymer Electrolytes
• Solid symmetric ECs – Metallic ECs
– Double Layer ECs
– Pseudocapacitve ECs
• Expansion of Cell Voltage – Alternative Electrolytes
– Asymmetric
– Multicell-in-one package
• Summary
• Key words: high rate, solid/flexible
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Fast device response, small time constant, high power density
0.9 mF/cm2
Onion-like carbon 1
Et4NBF4/propylene carbonate
Graphene nanosheets 2
KOH
90 µF/cm2 (120 Hz)
Reduced graphene oxide 3
H3PO4
0.3 mF/cm2
1. D. Pech, et.al, Nature Nanotechnology 5 (2010) 651
2. J.R. Miller, et.al, Science 329 (2010) 1637.
3. K. Sheng, et.al Scientific Reports 2 (2012).
4. M.F. El-Kady, et.al., Science 335 (2012) 1326.
Laser scribed graphene 4
KOH
1.5 mF/cm2 (10V/s)
Advanced electrodes
Liquid electrolytes
Our goal
Flexible/rollable
EC devices
State-of-the-Art High Rate ECs
?
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Battery –Capacitor Hybrid System
– The thin and flexible ultracapacitor can have various form factor
– It can be readily combined with the energy sources
Vo
ltag
e (
V)
2.5 A Pulse, Peak Power > 2.25 W
0.9
1
1.1
1.2
1.3
1.4
1.5
0 20 40 60 80 100
time (min)
EC+Battery hybrid
Battery
only
0.9
1
1.1
1.2
1.3
1.4
1.5
0 10 20 30 40 50
time (min)
EC+Battery hybrid
Battery
only
3.6 A Pulse, Peak Power > 3.4 W
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Solid State ECs – polymer electrolytes
To eliminate metal cans and separators to form
flexible dry ECC
Current
Liquid Electrolyte
“SOLID” ELECTROLYTE
“SOLID” ELECTROLYTE
BiPOLAR ELECTRODE
ELECTRODE
ELECTRODE
multicell in one package
polymer electrolyte
Polymer Electrolyte
9
Solid Electrochemical Capacitors
M. El-Kady, et al. Science, 335, 1326 (2012)
Yuan et.al, ACS Nano 6(1) 656 (2012)
K. Lian et.al. US Patent, 5,587,872, (1996)
RuO2 based solid 10-cell EC
10 V/s
Polymer Electrolytes:
PVA-H3PO4
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10
Heteropolyacid (HPA)
• High ionic conductivity at solid state
• Low cost
• Less aggressive chemistry
• Have been considered in fuel cells and sensors
H3PW12O40.29H2O H3PMo12O40.29H2O H4SiW12O40.28H2O
Proton con-
ductivity (S/cm) 0.17 0.18 0.027
0 0.25 0.50-0.10
-0.05
0
0.05
0.10
E (V) vs. Ag/AgCl
I (A
*cm
-2)
1. Bare MWCNT2. Single PMo12
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Voltage Operation Window of HPA
*Altenau et.al, Inorg. Chem ., 14, 417, (1975)
Dependence of the 1st one - e- reduction
pontntials on the negative charge: 1)
XW12O40n- and 2) XV12O40
n-
-0.5 0 0.5 1.0 -0.075
-0.050
-0.025
0
0.025
0.050
E (V) vs. Ag/AgCl I
(Am
ps/c
m
2 )
SITA-GRAPHITE-ELECTRODE(-02-1)_Cy04.cor H2SO4-GRAPHITE-ELECTRODE(13)_Cy04.cor PTA-GRAPHITE-ELECTROD(-02-1)E_Cy04.cor
H2SO4
SiWA
PWA
Lian et al. Electrochem. Solid-State Letters, 11(9) A158 2008
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Graphite cell with H2SO4, PWA and SiWA (EDLC)
0 0.25 0.50 0.75 1.00 -0.002
-0.001
0
0.001
0.002
E (V)
I (A
mp
s/c
m2)
GRAPHITE CELL-H2SO4
GRAPHITE CELL-PWA
GRAPHITE CELL-SIWA
0.3 M solution; Sweep Rate = 100 mV/s
0 0.25 0.50 0.75 1.00 -0.010
-0.005
0
0.005
0.010
0.015
E (V)
I (A
mp
s/c
m2)
RuO2 CELL-H2SO4 RuO2 CELL-PWA RuO2 CELL-SiWA
Lian et al. Electrochemical and Solid-State Letters, 11(9) A158 (2008)
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Issues and Approaches
Issues of HPAs:
• Poor film forming – Often, HPA are pressed as pellets
• Soluble in water
• Sensitive to moisture and temperature
A good solid electrolyte should possess: High ionic conductivity at all temperature range
High stability and shelf life
Our Approach:
• Composite with polymer to immobilize the HPAs
• Additives
14
Composition of Polymer Electrolytes
Polymer matrix:
Polyvinyl alcohol
(PVA)
Additives:
Glutaraldehyde
Silica oxide
Phosphoric acid
Our polymer electrolytes are comprised of 3 functional
components:
Ionic conductor:
Heteropoly acid
Silicotungstic acid
H4SiW12O40.28H2O (SiWA)
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•Lower HPA sensitivity on environment
•Form thin film electrolyte
•Achieve better electrode/electrolyte contact
HPA - Polymer Systems
HPA + additives + Polyvinyl alcohol (>90 wt.%) (<10 wt.%)
Gen I • SiWA + PVA
Gen II • SiWA + H3PO4 + PVA
Gen III • SiWA + H3PO4 + Crosslinked-PVA
(XL-PVA)
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Cell Assembly
Electrolyte thickness ≈50 μm
Electrolyte coating
Hot-pressing 90 oC
Film lamination
Electrode (Stainless steel foils or RuO2 on Ti foils)
PVA-SiWA-H3PO4
Electrode area 0.8 cm2 Cell thickness ≈ 0.2 mm
Pressure and
temperature
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Proton Conductivity of
the Polymer Electrolytes
Stainless Electrodes
17
18
Conductivity of Polymer Electrolytes
•Stainless steel electrodes
•Measured in ambient condition
0 10 20 30 40 50 60 70
0.000
0.005
0.010
0.015
0.020
0.025
0.030
0.035
Gen III (SiWA-H3PO
4-XL-PVA)
Gen II (SiWA-H3PO
4-PVA)
Con
du
ctiv
ity (
S c
m-1
)
Day
Gen I (SiWA-PVA)
SiWA
SS
Poly electrolyte
SS
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3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8-5.0
-4.8
-4.6
-4.4
-4.2
-4.0
-3.8
-3.6
-3.4
-3.2
-3.0
-2.8
-2.6
R2=0.98
No cross-linking
Cross-linked (solid polymer)ln
(co
nd
ucti
vit
y)
(Scm
-1)
1000/T (K-1)
R2=0.98
0 oC to 50 oC at 50% RH
9.2 kJ/mol
14.8 kJ/mol
Proton hopping in crystalline material
Arrhenius plot
H. Gao, K. Lian, Journal of Materials Chemistry, 22 (2012) 21272.
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Conductivity and Stability (Comparison with Nafion)
0 2 4 6 8 10 12 14 16
0.000
0.005
0.010
0.015
0.020
0.025
Conduct
ivit
y (
S c
m-1
)
Days
SiWA-H3PO
4-PVA cell
Nafion cell
SS
Poly electrolyte
SS
H. Gao, H. Wu, K. Lian, Electrochem. Commun., Vol 12, p48 (2012)
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Structural Analyses (XRD) (cont)
21
10 20 30 40 50
Inte
nsi
ty (
a.u
.)No cross-linking
Inte
nsi
ty (
a.u
.)
Cross-linked - (solid-polymer)
Inte
nsi
ty (
a.u
.)
2-Theta
Cross-linked - (gel-polymer)
10 20 30 40 50
Inte
nsi
ty (
a.u
.)No cross-linking
10 20 30 40 50
Inte
nsi
ty (
a.u
.)No cross-linking
Inte
nsi
ty (
a.u
.)
Cross-linked - (solid-polymer)
No long range order & crystal structure
HPA-PVA (solid)
HPA-XLPVA (solid)
Dehydration Hydration Keggin crystal structure
HPA-XLPVA (gel)
H. Gao, K. Lian, Journal of Materials Chemistry, 22 (2012) 21272.
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Solid ECs
Metallic electrode
Stainless steel
EDLC electrode
Graphite
Pseudocapacitive
electrode
RuO2 , MoxN
22
Solid Metallic EDLC
0.0 0.2 0.4 0.6 0.8 1.0
-0.08
-0.06
-0.04
-0.02
0.00
0.02
0.04
0.06
0.08C
urr
ent
densi
ty (
Acm
-2)
Cell voltage (V)
H2SO
4 Nafion
HPA-XLPVA
5,000 V/s
23
SS
electrolyte
SS
H. Gao, K. Lian, Journal of Materials Chemistry, 22 21272.(2012)
24
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
-0.08
-0.06
-0.04
-0.02
0.00
0.02
0.04
0.06
0.08
Curr
ent
densi
ty (
A c
m-2
)
Cell voltage (V)
Nafion cell
SiWA-H3PO
4-PVA cell
(a) Day 1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
-0.08
-0.06
-0.04
-0.02
0.00
0.02
0.04
0.06
0.08
Day 14(b)
Cu
rren
t d
en
sity
(A
cm
-2)
Cell voltage (V)
Nafion cell
SiWA-H3PO
4-PVA cell
SiWA + H3PO4 + PVA vs. Nafion®
• Polymer electrolyte) have exceeded Nafion® in stability.
Both solid EC devices are tested at an Ultra high Rate of 5000 V/s
Day 1 Day 14
H. Gao, H. Wu, K. Lian, Electrochem. Commun., Vol 12, p48 (2012)
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0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9-0.004
-0.003
-0.002
-0.001
0.000
0.001
0.002
0.003
0.004
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9-0.04
-0.03
-0.02
-0.01
0.00
0.01
0.02
0.03
0.04
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9-0.08
-0.06
-0.04
-0.02
0.00
0.02
0.04
0.06
0.08
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9-0.14
-0.12
-0.10
-0.08
-0.06
-0.04
-0.02
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
Cu
rren
t d
en
sity
(A
cm
-2)
Cell voltage (V)
1 Vs-1
Cu
rren
t d
en
sity
(A
cm
-2)
Cell voltage (V)
10 Vs-1
Cu
rren
t d
en
sity
(A
cm
-2)
Cell voltage (V)
25 Vs-1
Cu
rren
t d
en
sity
(A
cm
-2)
Cell voltage (V)
50 Vs-1
2.5 mF/cm2
2 mF/cm2
H. Gao, K. Lian, Journal of Materials Chemistry, 22 21272.(2012)
Solid Graphite EDLC
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0.0 0.4 0.8 1.2 1.6 2.00.0
0.2
0.4
0.6
0.8
1.0
Cell
volt
age (
V)
Time (s)
5 mA/cm2, 2.6 mF/cm2
0.1 1 10 100 1000 10000 100000
0.0000
0.0005
0.0010
0.0015
0.0020
0.0025
0.0030
C'
Frequency (Hz)
C' (F
cm
-2)
0.0000
0.0002
0.0004
0.0006
0.0008
0.0010
0.0012
C''
(Fcm
-2)
C''10 ms
Graphite EDLC: Charge-discharge & EIS
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0 2 4 6 8 10 12 14
0.0
0.2
0.4
0.6
0.8
1.0
Cell
vo
lta
ge (
V)
Time (s)
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9-0.15
-0.10
-0.05
0.00
0.05
0.10
0.15
Cu
rren
t d
en
sity
(A
cm
-2)
Cell voltage (V)
5 Vs-1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9-0.04
-0.03
-0.02
-0.01
0.00
0.01
0.02
0.03
0.04
Cu
rren
t d
en
sity
(A
cm
-2)
Cell voltage (V)
1 Vs-1
30 mF/cm2 10 mF/cm2
8.3 mA/cm2, 32 mF/cm2
0.1 1 10 100 1000 10000 100000
0.000
0.005
0.010
0.015
0.020
0.025
0.030
C'
C''
Frequency (Hz)
C' (F
cm
-2)
0.000
0.002
0.004
0.006
0.008
0.010
C''
(Fcm
-2)
100 ms
RuO2 Solid pseudocapacitor
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Solid vs. Liquid MoxN EC Cell
Sweep rate = 1 V/s Sweep rate = 10 V/s H. Gao, K. Lian, Journal of Power Sources, 222(15) 301 (2013)
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Solid EC Cell at High Rates
Sweep rate = 50 V/s Sweep rate = 100 V/s
H. Gao, K. Lian, Journal of Power Sources, 222(15) 301 (2013)
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Solid vs. Liquid EC Cell – EIS Analyses
H. Gao, K. Lian, Journal of Power Sources, 222(15) 301 (2013)
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Voltage Window Expansion
Organic or Ionic Liquid Polymer Electrolytes.
Asymmetric Cell
Multi-cell-in-One package
31
32
Electrolyte coated on electrode active material • Polymer/acid gel blends • Thin film polymer
electrolyte 30 to 50m
Electrode active materials coated on substrate
• Activated/modified carbon • Mixed metal oxides • Conductive polymers • CNT
Asymmetrical Polymer-based Capacitor
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Fabrication of Solid Asymmetric Cell
Pressure and
temperature
Film conductivity 0.01 S/cm
Thickness 0.4 – 0.6 mm
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Solid Asymmetric Ecs (graphite-RuO2)
0 0.5 1.0 1.5
-0.0050
-0.0025
0
0.0025
0.0050
E (Volts)
I (A
mp
s/c
m2)
GRAPHITE-PTA-629-100(14)-DAY1.cor
5 10 15 20 25
0
0.5
1.0
1.5
Time (Sec)
E (
Vo
lts)
GRAPHITE-PTA-629-1000(14)-DAY4-CHARGE-DISCHARGE-100.cor
K. Lian et.al, Electrochemistry Communications 12(4) 517 (2010)
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35
Terminal electrode
• Multi-cell EC in single package
– Two ECs in series (bipolar plate)
– Smaller device capacitance
– Higher cell voltage window
Solid multi-cell-in-one package ECs
Bipolar electrode
Polymer electrolyte
Terminal electrode
36
At 5,000 V/s scan rate
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
-0.04
-0.03
-0.02
-0.01
0.00
0.01
0.02
0.03
0.04
Curr
ent
densi
ty (
A c
m-2)
Cell voltage (V)
Cycle No. 100
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
-0.04
-0.03
-0.02
-0.01
0.00
0.01
0.02
0.03
0.04
Curr
ent
densi
ty (
A c
m-2)
Cell voltage (V)
Cycle No. 100
Cycle No. 20,000
Solid Metallic 2-cell-in-1 EC
• Increased voltage window and excellent cycle life
H. Gao, H. Wu, K. Lian, Electrochem. Commun., Vol 12, p48 (2012)
SS
Poly electrolyte
SS
Poly electrolyte
SS
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0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
-0.008
-0.006
-0.004
-0.002
0.000
0.002
0.004
0.006
0.008
1 Vs-1
Cu
rren
t d
en
sity
(A
cm
-2)
Cell voltage (V)
Solid Carbon Based 2-cell-in-1 EDLC
Single Cell
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
-0.003
-0.002
-0.001
0.000
0.001
0.002
0.003
Cu
rren
t d
en
sity
(A
cm-2
)
Cell voltage (V)
1 Vs-1
2-Cell-in-1 package
Electrodes: Graphite on Stainless Steel foils
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0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
-0.003
-0.002
-0.001
0.000
0.001
0.002
0.003
Cu
rren
t d
en
sity
(A
cm
-2)
Cell voltage (V)
1 Vs-1
Solid Carbon Based 2-cell-in-1 EDLC
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
-0.020
-0.015
-0.010
-0.005
0.000
0.005
0.010
0.015
0.020
Cu
rren
t d
en
sity
(A
cm-2
)
Cell voltage (V)
10 Vs-1
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
-0.04
-0.03
-0.02
-0.01
0.00
0.01
0.02
0.03
0.04
Cu
rren
t d
en
sity
(A
cm-2
)
Cell voltage (V)
25 Vs-1
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
-0.06
-0.04
-0.02
0.00
0.02
0.04
0.06
Cu
rren
t d
en
sity
(A
cm-2
)
Cell voltage (V)
50 Vs-1
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1 10 100 1000 10000 1000000.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
1 10 100 1000 10000 1000000.0
0.2
0.4
0.6
0.8
1.0
1.2
C'
(mF
cm
-2)
Frequency (Hz)
Single cell
Multi-cell
C''
(m
F c
m-2
)
Frequency (Hz)
Single cell
Multi-cell
Solid Carbon Based 2-cell EC (Impedance)
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Latest: Alkaline based solid electrolyte
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40
Rate: 2000 V/s 50C to -10C
41
Summary
• SiWA - H3PO4 – PVA electrolytes have been
shown to
1. perform equal or better than liquid aqueous electrolyte;
2. be applicable for both EDLC and pseudocapacitors.
3. store and deliver charge at ultrahigh rates;
4. retain its conductivity and ultrahigh rate capability over
time, yielding excellent shelf and cycle life;
5. enable multi-cell ECs in single package without
sacrificing rate capability.
• Solid polymer electrolytes are viable for high rate
and high power energy storage devices.
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Acknowledgement • Electrolytes:
– Han Gao, Sanaz Ketabi, Haoran Wu, Jak Li, Alex Dilio and
Blair Decker
• Electrodes
– Gurvinder Bajwa, Fred Xiao, Matt Genovece, Terence Lee
• Applications
– Jin Chang, Ahmed Huzayin, Bernie Ting,
• NSERC Canada
• Ontario Research Fund
• Ontario Center of Excellence
• University of Toronto
Lian – 2013