Electronic Supplementary Material (ESI) for Journal of Materials Chemistry A.
This journal is © The Royal Society of Chemistry 2017
Supporting Information
An all-solid-state-supercapacitor possessing a non-aqueous
gel polymer electrolyte prepared using a UV-assisted in-situ
polymerization strategy
Vidyanand Vijayakumara,d, Bihag Anothumakkoola,c, ‡, Arun Torris A.Tb, ‡, Sanoop B. Nairb, Manohar V. Badigerb,d*
and Sreekumar Kurungota,d*
a.
Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Pune, Maharashtra,
India – 411008. E-mail: k.sreekumar@ncl.res.in
b. Polymer Science and Engineering Division, CSIR-National Chemical Laboratory, Pune, Maharashtra,
India – 411008. E-mail: mv.badiger@ncl.res.in
c. Electrochemical Storage and Conversion of Energy Institut de Matériaux de Nantes, France
d. Academy of Scientific and Innovative Research (AcSIR), CSIR-NCL Campus, Pune, Maharashtra,
India – 411008
1
CONTENTS
S/No.
1.
Details of Electrochemical Characterisations.
Page
No.
3
2.
Device Fabrication.
3
3.
NMR spectrum of the HPA monomer and PHPA. (Fig. S1(a) and (b))
4
4.
Mechanical properties of PHPA, H-P-80%, GPEs and electrodes. (Fig. S2)
5
5.
ATR-FTIR spectral investigation. (Fig. S3)
6
6.
Structure of the Monomers used. (Fig. S4)
7
7.
Nyquist plot of the M-P-L-3M-60% GPE. (Fig. S5)
8
8.
FE-SEM image, EDX analysis and BET adsorption-desorption isotherms of YP-80F.
(Fig. S6)
9
9.
Dimension of the HPA monomer. (Fig. S7)
9
10.
Electrochemical characterisation of the supercapacitor devices. (Fig. S8,S9,S10 and
S11)
Comparison between the in-situ and conventional device fabrication strategies.
(Fig. S12 and S13)
EDX mapping of the carbon sample after the in-situ polymerization. (Fig. S14)
10-11
11.
12.
Title of the Section
12
13
13.
Cross sectional FE-SEM image of the H-P-L-3M-S-3.8 and PMMA-PC-L-3M-S-3.8 13
device. (Fig. S15)
14.
Comparison of mechanical stability of Bare electrode and GPE coated electrode.
(Fig. S16 and S17)
Specific capacitance of the scaled up devices at various current densities in the
scale of A g-1. (Fig. S18)
Comparison and summary of the current work to already reported works in the
literature. (Table. 1)
15.
16.
2
14
15
16
1. Electrochemical Characterizations1
The equation (1) is used for the calculation of Gravimetric capacitance (F g-1) from the charge-discharge method.
𝐶=
where,
2 × (𝐼 × ∆𝑡)
∆𝑉 ∗ 𝑀
(1)
Δt = Discharge time
ΔV = Potential window
I = Constant current used for charging and discharging
M = Weight of active carbon material in one of the electrode
The obtained device capacitance was multiplied by a factor of 2 in order to get the single electrode capacitance which is included in
Equation 1.
Gravimetric energy density (Ed) and power density (Pd) were calculated from the capacitance value obtained from the charge-discharge
method.
𝐶𝑠
𝑉2
Energy density (Ed) ((Wh kg-1)) = 8 × 3.6
(2)
where,
‘Cs’ is the specific capacitance calculated by the charge-discharge (F g-1) method and ‘V’ is the voltage window.
𝐸𝑑
Power density (Pd) ((W kg-1)) = 𝑡
(3)
where, ‘Ed’ is the energy density from Equation 3 and ‘t’ is the discharge time in hour calculated from the discharge curve.
The ionic Conductivity of the GPEs films were calculated from the equation (5).
𝜌 (Ω 𝑐𝑚) =
𝑅𝐴
𝑙
(4)
σ= Conductivity of the membrane
ρ = Resistivity of the membrane
R = bulk resistance of the membrane
A = Area of the membrane
l = Thickness of the membrane
𝜎 (𝑆 𝑐𝑚 ‒ 1) =
1
𝜌
(5)
2. Device fabrication
Fabrication of the ex-situ and M-P-L-3M-60%-S-3.0 devices
The supercapacitor device was fabricated using an ex-situ strategy where the H-P-L-3M-80% GPE film (Thickness = 0.25 mm)
was prepared first in a Teflon mould and then sandwiched in between two electrodes as in the case of device fabrication using
the conventional dry polymer electrolytes. The hence prepared device is hereafter termed as H-P-L-3M-S-ex-xitu, where ‘S’
stands for the solid device. The electrode mass loading was 3.0 mg cm-2.
The supercapacitor device fabricated using the in-situ prepared M-P-L-3M-60% GPE is hereafter termed as M-P-L-3M-60%-S3.0, where ‘S’ stands for the solid device and ‘3.0’ stands for the electrode mass loading. The procedure used for the device
fabrication is the same as it was used for the preparation of the HPA based devices except the fact that the pre-polymerised
solution used in the case of MMA based device is M-P-L-3M-60%.
The electrochemical performance of the M-P-L-3M-60%-S-3.0 and the H-P-L-3M-S-ex-xitu devices were compared with the
HPA based solid-state and liquid-state devices.
3
3. NMR spectrum of the HPA monomer and PHPA.
Fig. S1a
13C-NMR
Fig. S1b
spectra of the HPA monomer.
13C-NMR
spectra of PHPA polymer.
4
4. Mechanical properties of PHPA, H-P-80%, GPEs and electrodes
1. Dynamic mechanical analysis.
Dynamic mechanical analyzer (DMA) (RSA III, TA Instruments USA) equipped with TA Orchestrator software (Version 7.2.0.4) was
used for the uni-axial tensile measurements (static mode) and dynamic compression measurements (dynamic mode) of H-P-L-xM-y%
GPEs. For the uni-axial tensile measurements, H-P-L-3M-80% GPE specimens with a rectangular geometry of 5 mm width, 0.8 mm
thickness and 15 mm length were prepared. Specimens were clamped onto tensile grips with a constant torque of 20 cN.m and applied the
load at a speed of 1 mm min-1 up to failure. Dynamic mechanical measurements were performed on cylindrical specimens (8 mm dia. x 8
mm height) of neat PHPA, H-P-80% and H-P-L-xM-80% (x = 1,2 and 3) GPEs. Initially, linear visco-elastic region (LVR) of the gels was
identified by performing linear strain sweep measurements followed by frequency sweep analysis to measure the modulus of the
specimens in the range 0.1 to 10 Hz at ambient temperature.
For the uni-axial tensile measurements of the electrodes, two sets of electrodes were prepared. One set of electrodes coated with carbon
and another set with carbon as well as photo-polymerized gel electrolyte. Electrode dimensions were 20 mm width, 0.5 mm thickness and
40 mm height. Electrodes were loaded onto the tensile grips of universal testing machine (Model: Instron 5943, Instron Ltd., MA, USA)
with the aid of elastomeric strips on both side of the electrodes to avoid slippage during measurements. A pre-load to 0.01 N is applied to
rectify the alignment and tensile test is performed upto rupture at the cross-head speed of 3 mm/min.
2 . Uni-axial un-confined compression and cyclic compression measurements
Uni-axial un-confined compression and cyclic compression measurements were performed with cylindrical H-P-L-3M-80% and H-P-80%
gels of 15 mm diameter and 15 mm height using single column table top electro-mechanical material testing station of 1kN load cell
capacity (Model: Instron 5943, Instron Ltd., MA, USA), equipped with cylindrical compression platens of 50mm diameter and Bluehill 3
software with TestProfiler module for recording as well as analysis of data sets. To prevent slippage and displacement of gels during the
measurements, both compression plate surfaces were glued with sand-coated paper of grade 100 (Multicut Paper, Vinal Abrasives, India).
A pre-load of 0.01 N is applied prior to compression measurements to attain uniform contact between the surface of gels and compression
platens. A cross-head speed of 10 mm min-1 is used for all compression measurements with ±0.1% speed and position accuracy. Minimum
of 3 samples were measured and representative histograms were plotted.
Uni-axial compression was performed on H-P-L-3M-80% and H-P-80% gels up to 98% compression or till specimen failure, whichever is
earlier. Two sets of the uni-axial cyclic compression measurements were performed on cylindrical H-P-L-3M-80% and H-P-80% gels with
the first set of measurement comprising of a sequence of 8 or 9 cyclic measurements with varying compressive strain starting from 10 to
80 or 90 %. The second set of cyclic measurement involves continuous 200 cycles of compression at constant 70 or 90% compressive
strain without interval. The samples used were having a dimension of Hysteresis energy is calculated from the histogram of compressive
stress versus compressive strain following Equation 62 given below:
0.9𝑙𝑜𝑎𝑑𝑖𝑛𝑔
𝑈90% =
∫
0
𝐹d𝑠 ‒
0.9𝑢𝑛𝑙𝑜𝑎𝑑𝑖𝑛𝑔
𝜋𝑟2
∫
0
𝐹 d𝑠
………..………….. (6)
where, ‘U90%’ represents the dissipated energy for 90% compressive strain, ‘F’ is the loading, ‘s’ is the displacement to the corresponding
strain and ‘r’ is the radius of the gel.
5
Fig. S2 (a) Sequential uni-axial compression cycles of H-P-80% from 10 to 80% strain where the inset shows the maximum stress per
cycle versus the corresponding strain from 40% to 70% compression strain; (b) hysteresis energy of the sequential uni-axial compression
cycles from 10 to 80% compressive strain for H-P-80%; (c) Compressive stress vs. Compressive strain plot recorded for 200 repeated
cycles of uni-axial compression for H-P-80% gel at an interval of each 50 cycles.
5. ATR-FTIR spectral investigation
From Figure 2c, comparing the FTIR spectrum of the monomer and neat PHPA, the peak corresponding to the C=C stretching at 1629 cm1 is present in the monomer, whereas, it is absent in the case of the polymer PHPA. The C=O stretching band of the monomer is observed
at 1717 cm-1, whereas, in the polymer, it is shifted to a frequency of 1729 cm-1. This is due to the difference between the α,β-unsaturated
conjugated carbonyl in acrylate double bonds and the α,β-saturated conjugated carbonyl in the polymer.3 This further confirms that the
polymerisation is complete which is already been proved from NMR. In the spectrum of H-P-80%, the peak corresponding to the carbonyl
group of the polymer matrix of PHPA shows a shift from 1729 cm-1 to 1737 cm-1. This blue shift can be attributed to the hindrance to the
hydrogen bonding present in the polymer matrix, once the plasticizer solvent (PC) is introduced into the system. In the case of pure PC, the
FTIR data shows a peak at 1781 cm-1 which corresponding to the stretching mode of the C=O group of PC.4 In the GPEs, this peak (1781
cm-1) shows a gradual redshift as the concentration of the LiClO4 is increased. This is attributed to the interaction between the carbonyl
group of PC and the Li+ cation. At the same time, it is observed that the peak at 1737 cm-1 also shows a shift towards lower frequency
when the LiClO4 is introduced and on successive increment in the concentration of LiClO4, the peak is disappeared. The disappearance of
the peak is due to the broadening of the peak corresponding to the carbonyl group of PC, where, it is merged with the carbonyl peak of the
polymer matrix. Moreover the amount of the solvent is excess in the system compared to the polymer, which also contributes to the
disappearance of the carbonyl band of the polymer matrix. The increase in the intensity of the peak at 624 cm-1 as the concentration of
LiClO4 increases in the gel polymer electrolyte is attributed to the increase in amount of the free ClO4- ions. This confirms the improved
dissociation of the conducting salt in the H-P-L-3M-80% gel polymer electrolyte compared to the others.
Fig. S3 ATR-FTIR spectra magnified between 1600 cm-1 to 2000 cm-1.
6
6. Structure of the Monomers used
Fig. S4 The structure of the HPA and MMA monomers.
7
7. Nyquist plot of the M-P-L-3M-60% GPE
Fig. S5 Nyquist plot of the M-P-L-3M-60% GPE.
8
8. FE-SEM image, EDX analysis and BET adsorption-desorption isotherms of YP-80F.
Fig. S6 (a) FESEM image of YP-80F; (b) EDAX of YP-80F; (c) N2-adosption isotherm of the carbon (YP-80F) used for preparing the
electrode for the supercapacitor; (d) Pore-size-distribution profile of the carbon powder used for making the device.
9. Dimension of the HPA monomer
Fig. S7 Optimized conformation of the monomer (HPA) at PBE/TZVP level of theory. Distances between the hydrogen atoms are given in
Angstrom (Å) unit.
Full quantum mechanical calculations were done with density functional theory (DFT) at the PBE/TZVP5, 6 level of theory using
Turbomole 7.0 program7 in order to gain further insight into the dimension and geometry of the HPA monomer. The optimized geometry
is shown in Figure S7. The maximum distance between the two terminal atoms (H(1) and H(3)) is 11.412 Å, which is very much less than
that of the carbon pore size (10-15 Å). The XYZ coordinates of the PBE/TZVP optimized geometry are given at the end of SI (Page
No.17).
9
10. Electrochemical characterisation of the supercapacitor devices
Fig. S8 (a) to (c) Combined Nyquist plot (a), CV profile recorded at a scan rate of 50 mV s-1 (b) and CD profile recorded at a current
density of 2 mA cm-1 (c) for the supercapacitor devices: H-P-L-xM-S-3.0, where ‘x’= 1,2 and 3; (d) to (f) The combined CV profile at a
scan rate of 50 mV s-1 (d), Nyquist plot (e) and the CD profile recorded at a current density of 2 mA cm-2 (f) taken for the various liquidstate and solid-state devices under the study.
Fig. S9 Comparison of the Specific capacitance values obtained for the various devices at a current density of 2 mA cm-1.
10
Fig. S10 (a) to (c) Combined Nyquist plot (a), CV profile recorded at a scan rate of 50 mV s-1 (b) and CD profile recorded at a current
density of 2 mA cm-1 (c) for the supercapacitor devices: H-P-L-3M-S-3.0 and M-P-L-3M-60%-S-3.0 ; (d) plots representing the Mass
Specific Capacitance vs. Current Density for the H-P-L-3M-S-3.0 and M-P-L-3M-60%-S-3.0 devices.
Fig. S11 Combined Ragone plot comparing the energy and power density of H-P-L-3M-S-3.0 and M-P-L-3M-60%-S-3.0 supercapacitor
devices.
11
11. Comparison between the in-situ and conventional device fabrication strategies
Fig. S12 (a) to (c) Complete CV profiles of the supercapacitor devices: H-P-L3M-S-3.8 (a), H-P-L-3M-L-3.8 (b) and PMMA-PC-L-S-3.8
(c) ; (d) to (f) complete CD profiles of the H-P-L-3M-S-3.8 supercapacitor devices: H-P-L-3M-S-3.8 (d), H-P-L-3M-L-3.8 (e) and
PMMA-PC-L-S-3.8 (f).
Fig. S13 Charge-discharge profile recorded for the YP-80F carbon at a current density of 2 mA cm-2 in standard non-aqueous electrolyte
(3 M LiClO4/PC) at (a) 2.0 V window (b) 2.5 V window.
12
12. EDX mapping of the carbon sample after the in-situ polymerization
Fig. S14 EDX mapping of the carbon sample after the in-situ polymerization: (a) carbon portion which is taken after the in-situ
polymerization from the device; (b)-(d) elemental mapping of carbon (b), Oxygen (c) and Chlorine (d) which are corresponding to the area
represented in (a).
13. Cross sectional FE-SEM image of the H-P-L-3M-S-3.8 and PMMA-PC-L-3M-S-3.8 device
Fig. S15 (a) and (b) The cross sectional FE-SEM image of the H-P-L-3M-S-3.8 device; (c) and (d) The cross sectional FE-SEM image of
the PMMA-PC-L-3M-S-3.8 device.
13
14. Comparison of mechanical stability of Bare electrode and GPE coated electrode.
Fig. S16 (a) Blank-electrode before the in-situ GPE generation; (b) Electrode after the in-situ GPE generation; (c) The electrode in bent
condition after the in-situ GPE generation.
Fig. S17 Tensile stress vs. tensile strain plot of electrodes with and without GPE.
14
15. Specific capacitance of the scaled up devices at various current densities in the scale of A g -1.
Fig. S18 The specific capacitance of the devices H-P-L-3M-S-2.5 (a) and H-P-L-3M-S-4.0 (b) at various current densities in the scale of
A g-1.
15
16. Comparison and summary of the current work to already reported works in the literature
Active
Electrode
material
Specific
Capacitance
Reference
GPE used
Details of Device Fabrication
ESR
Poly (HEMA-coMMA) with DPHPO4
GPE film is used, Tested the device in Sweaglock
Cell, Electrodes pre-soaked with Electrolyte,
Electrode area = 1.28 cm2, Active material loading =
2 mg cm-2.
95 Ω cm2
123 F g-1 at
0.78 mA g-1
11
Main Text
Silica Nano-Powder
with [EMIM][NTf2]
Quasi-solid state Gel electrolyte pressed in between
the electrodes, Electrode area = 1 cm2, Low Active
material loading = 0.23 mg cm-2.
30 Ω
135 F g-1 at 2
A g-1
68
Main Text
3. AC
Poly (OEGMA-coBnMA)
Organic electrolyte swollen GPE film is used, Area of
the device = 1.13 cm2, Mass loading = Mass
loading=3.1 mg cm-2.
20 Ω cm
24 F g-1 at at
0.8 A g-1
23
Main Text
4. AC
PEO-NaTFSI
Quasi-solid state GPE, Electrode area= 1 cm2, Active
material loading 4-5 mg, Device testing details are
not provided.
6.8 Ω
25.6 F g-1 at
200 mA g-1
69
Main Text
5. CNT
PS-PEO-PS tri-block
copolymer with
[EMIM][NTf2]
Quasi-solid-state GPE spread over electrode, Device
area = 1 cm2, Loading not mentioned.
31.3 Ω
50.5 F g-1
at 1 A g-1
6. YP-80F
H-P-L-3M-80%
In-situ GPE generation, Solid-state GPE, Electrode
Area = 16 cm2, Mass loading= 4.5 mg cm-2
2.2 Ω
111 F g-1
at 0.20 A g-1
1. YP-80F
2. CNT
at
21
Main Text
This Work
Table 1 : The electrochemical performances among the GPE based supercapacitor devices already reported in the literatures and the
devices reported in this work are compared and summarised.
References
1.
2.
3.
4.
5.
6
W. Chen, Z. Fan, L. Gu, X. Bao and C. Wang, Chemical Communications, 2010, 46, 3905-3907.
J. Wei, J. Wang, S. Su, S. Wang and J. Qiu, Journal of Materials Chemistry B, 2015, 3, 5284-5290.
T. Y. Lee, T. M. Roper, E. S. Jönsson, C. A. Guymon and C. E. Hoyle, Macromolecules, 2004, 37, 3659-3665.
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A. Schäfer, C. Huber and R. Ahlrichs, The Journal of Chemical Physics, 1994, 100, 5829-5835.
7.
TURBOMOLE V7.0 2015, a development of University of Karlsruhe and Forschungszentrum Karlsruhe GmbH, 1989-2007,
TURBOMOLE GmbH, since 2007; available from http://www.turbomole.com.
16
The XYZ coordinates of the PBE/TZVP optimized geometry.
30
C
C
H
H
H
C
O
O
C
H
H
C
H
O
H
C
H
H
O
C
C
C
C
C
C
H
H
H
H
H
0.183106
0.398570
-0.235558
0.417605
0.817281
0.074176
-0.377788
0.357769
0.071032
0.731022
-0.975942
0.309426
1.365028
-0.575302
-0.508845
0.037482
-0.938741
0.001166
0.989693
2.212559
3.091518
2.607045
4.349393
3.873812
4.750364
2.762421
1.947899
5.023272
4.171489
5.736224
1.223204 0.163768
1.001557 1.465267
2.174431 -0.172097
0.469738 -0.588972
0.062629 1.832642
2.035022 2.479496
3.144080 2.263795
1.566418 3.735904
2.481780 4.826432
3.359454 4.761476
2.815435 4.755032
1.703417 6.108840
1.369565 6.126568
0.585130 6.222521
0.091643 5.385383
2.578210 7.336694
3.073385 7.235317
1.941955 8.235150
3.636084 7.468013
3.363546 8.038752
4.455698 8.112998
2.114835 8.540855
4.299561 8.688788
1.976383 9.120598
3.058582 9.199537
5.417483 7.716730
1.248418 8.487304
5.157041 8.740770
1.001222 9.511266
2.939905 9.651244
17