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SUPPLEMENTARY INFORMATION
Self-Assembly of Mesoporous Nanotubes Assembled from
Interwoven Ultrathin Birnessite-type MnO2 Nanosheets for
Asymmetric Supercapacitors
Ming Huang1, Yuxin Zhang1,2,*, Fei Li1, Lili Zhang3,*, Rodney S. Ruoff4,
Zhiyu Wen2 & Qing Liu1,*
1
College of Materials Science and Engineering, Chongqing University, Chongqing, 400044, P.R. China
2
National Key Laboratory of Fundamental Science of Micro/Nano-Devices and System Technology,
Chongqing University, Chongqing 400044, P.R. China
3
Institute of Chemical and Engineering Sciences, A*STAR, 1 Pesek Road, Jurong Island 627833,
4
Department of Mechanical Engineering and the Materials Science and Engineering Program, The
Singapore
University of Texas at Austin, One University Station C2200, Austin, Texas 78712, United States
* Corresponding author. Tel.: +86 23 65104131; Fax: +86 23 65104131
Email: zhangyuxin@cqu.edu.cn (Y.X. Zhang), zhang_lili@ices.a-star.edu.sg (L.L. Zhang) and
qingliu@cqu.edu.cn (Q. Liu)
1
Submitted to Scientific Reports
a)
3 µm
b)
1 µm
d)
c)
300 nm
100 nm
Figure S1. SEM images of PC membrane without treatment at different magnification.
b)
a)
8 µm
1 µm
2 µm
Figure S2. Cross-section SEM images of the PC membrane with different magnifications.
2
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a)
b)
2 µm
100 nm
Figure S3. SEM images of porous MnO2 nanotubes with different magnification: (a) cross-section
morphology of MnO2 nanotubes arrays; (b) detailed surface image of the MnO2 nanotubes. The
average thickness of MnO2 nanosheet is about 6 nm.
(a)
(b)
Figure S4. Nitrogen adsorption-desorption isotherms (a) and the pore size distribution plot from
the adsorption branch (b) of the MnO2 nanotubes.
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Table S1. Comparison of specific capacitances of the reported MnO2 electrodes and the present
work. All values are measured using the three-electrode system.
Samples
Hollow MnO2 microsphere
Cs (F g-1)
90
Electrolyte
1 M Na2SO4
Test condition
10 mV s-1
References
Amorphous MnO2
Birnessite MnO2
α-MnO2 hollow urchins
Ambigel MnO2
α-MnO2 nanorod
α-MnO2 hollow sphere
MnO2 nanorod
Birnessite hollow MnO2
MnO2 spherical particle
Mesoporous MnO2 particle
MnO2 nanowire
MnO2 nano hollow sphere
Porous MnO2 nanoparticle
MnO2 particle
MnO2 nanosheet
MnO2 microsphere
Porous nano-MnO2
MnO2 nanoparticle
α-MnO2 sphere
MnO2 with 3D framework
MnO2 nanowisker
Amorphous MnO2·nH2O
MnO2 nanorod
MnO2 nanosheet array
MnO2-pillared layered MnO2
MnO2 film
Birnessite MnO2 nanosphere
Todorokite-type MnO2
Coral-like MnO2
Mesoporous MnO2
Core-corona MnO2
MnO2 thin sheet
γ-MnO2 film
Lamellar MnO2
α-MnO2 nanorod
Amorphous nano MnO2
Amorphous MnO2 particle
α-MnO2 spherical-like particle
Porous MnO2 particle
Layered δ-MnO2
110
110
123
130
152
167
168
169
170.8
173
176
178
178.9
180
182
190
198.1
200
200
200
200
200
201
201
206
209
210
220
221
221
226
230
240
242.1
245
250
251
258.7
261
265
2 M NaCl
0.1 M K2SO4
0.5 M Na2SO4
2 M NaCl
1 M Na2SO4
1 M Na2SO4
1 M Na2SO4
1 M Na2SO4
0.5 M K2SO4
1 M Na2SO4
1 M Na2SO4
0.5 M K2SO4
1 M Na2SO4
0.5 M KOH
0.1 M Na2SO4
1 M Na2SO4
1 M Na2SO4
0.2 M K2SO4
0.25 M Na2SO4
0.5 M Na2SO4
1 M Na2SO4
2 M KCl
0.5 M Li2SO4
1 M Na2SO4
1 M Na2SO4
0.2 M Na2SO4
1 M Na2SO4
1 M Na2SO4
1 M Na2SO4
1 M Na2SO4
0.5 M Li2SO4
0.5 M Na2SO4
0.1 M Na2SO4
2 M NH4(SO4)2
1 M KOH
0.1 M Na2SO4
1 M Na2SO4
1 M Na2SO4
0.5 M K2SO4
1 M Na2SO4
5 mV s-1
2 mV s-1
2 mV s-1
5 mV s-1
5 mV s-1
2.5 mA cm-2
5 mV s-1
0.25 A g-1
0.5 A g-1
0.25 A g-1
5 mV s-1
0.5 A g-1
1 mV s-1
1 mV s-1
0.1 A g-1
0.5 A g-1
0.28 A g-1
5 mV s-1
1 A g-1
6 mA cm-2
2 mV s-1
5 mV s-1
1 mV s-1
1 A g-1
5 mV s-1
5 mV s-1
1 A g-1
2 mV s-1
0.5 A g-1
5 mV s-1
0.2 A g-1
20 mV s-1
1 mA cm-2
2 mA cm-2
1 A g-1
10 mV s-1
2 mV s-1
0.1 A g-1
0.5 mA cm-2
5 mV s-1
2
4
1
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
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1D birnessite-type MnO2
MnO2 porous film
Mesoporous α-MnO2 network
Amorphous MnO2 sphere
Mesoporous MnO2 nanoparticle
α-MnO2 spherical aggregate
Flower-like α-MnO2
MnO2 nanowire
Nanoscale MnO2
MnO2 tubular nanostructure
α-MnO2 nanoflake film
Spongy-like MnO2
MnO2 spherical particle
MnO2 thin film
MnO2 layered structure
α-MnO2 ultralong nanowire
MnO2 nanoflower
MnO2 hollow structure
Clew-like MnO2 particle
MnO2 nanofiber
Birnessite-type MnO2 nanotube
277
279
283
283
284.2
297
298
300
305
315
328
336
337
337
344
345
347
366
404.1
412
365
1 M Na2SO4
0.1 M Na2SO4
1 M Na2SO4
0.1 M Ca(NO3)2
1 M Li2SO4
0.1 M Na2SO4
1 M K2SO4
1 M Na2SO4
1 M Na2SO4
1 M Na2SO4
1 M Na2SO4
0.5 M Na2SO4
6 M KOH
2 M KCl
0.5 M Na2SO4
0.5 M Na2SO4
1 M Na2SO4
1 M Na2SO4
1 M Na2SO4
0.1 M Na2SO4
1 M Na2SO4
5
0.2 mA cm-2
2 mV s-1
2 mV s-1
0.5 mA cm-2
1 mV s-1
20 mV s-1
0.117 A g-1
5 mV s-1
2 mV s-1
0.2 A g-1
5 mV s-1
2 mA cm-2
2 mV s-1
400 mV s-1
5 mV s-1
1 A g-1
5 mV s-1
5 mV s-1
2 mV s-1
2 mV s-1
0.25 A g-1
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
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(a)
(b)
200 nm
200 nm
(d)
(c)
Figure S5. (a) SEM image of the commercial MnO2; (b) typical SEM image of MnO2 nanosheets
obtained without PC template; (c) CV curves of the commercial MnO2, MnO2 nanosheets, and
MnO2 nanotubes at a scan rate of 50 mV s-1 in 1 M Na2SO4 aqueous electrolyte; (d)
charge/discharge curves of the three samples at a current density of 0.25 A g-1
Table S2. Equivalent circuit parameters fitted from Nyquist plots for MnO2 nanotubes electrodes
(before and after 3000 charge/discharge cycles).
Samples
Rs (ohm cm2)
CPE1;Y0(Ss-n cm-2)
n1
Rct (ohm cm2)
Zw; Y0 (Ss-0.5 cm-2)
CPE2; Y0 (Ss-n cm-2)
n2
Before cycling
1.601
4.406×10-3
0.61
3.931
0.1894
0.4341
0.78
2.076
-3
0.59
7.358
0.1394
0.4363
0.98
After 3000 cycles
2.156×10
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a)
b)
300 nm
300 nm
d)
c)
100 nm
300 nm
Figure S6. SEM images of MnO2 nanotube electrodes: (a, b) initial MnO2 electrode before
electrochemical tests; (c, d) the MnO2 electrodes after 3000 charge/discharge cycles.
Figure S7. XRD patterns of MnO2 nanotube electrodes during charge/discharge cycles at the
current density of 1 A g-1.
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Figure S8. SEM images of the activated graphene (AG) in the asymmetric supercapacitor device.
(a)
(b)
(c)
(d)
Figure S9. Electrochemical tests of the activated graphene (AG) in a three-electrode configuration:
a, b) Cyclic voltammograms at scan rates of 5-200 mV s-1; (c, d) charge-discharge curves at
different current densities (0.2-8 A g-1).
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Figure S10. The electrochemical impedance spectrum of the MnO2 nanotubes//AG asymmetric
supercapacitor electrodes (before and after 10000 cycles) at open circuit potential in the frequency
range from 0.01 Hz to 100 kHz.
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Table S3. The capacitive properties of the containing-MnO2 supercapacitors.
Capacitor
Energy density (Wh kg-1)
Reference
Mo-doped manganese oxide//AC
MnO2//polyaniline(PANI)
MnO2//polypyrrole(PPy)
Graphene/MnO2//graphene/MnO2
MnO2//Fe3O4
MnO2//MnO2
Graphene/MnO2//graphene
MnO2//PEDOT
MnO2//activated carbon (AC)
NaMnO2//AC
Manganese oxide/AC//AC
Manganese Dioxide//AC
CNTs/MnO2//CNTs/SnO2
Hollow Cs-MnO2 nanofibers//hollow Cs
MnO2 nanoplates//graphene hydrogel
MnO2//FeOOH
Graphite oxide-MnO2//graphite oxide
MnO2//graphene
K0.27MnO2·0.6H2O//AC
RGO-MnO2-CNTs//AC-WCNT
Graphene-CNTs-MnO2//graphene-CNTs
MnO2 Nanorods//AC
MnO2 NWs-graphene composite//graphene
Graphene-MnO2//AC Nanofiber
CNT-Au-MnO2//AC
RGO-MnO2 hollow sphere
Ni(OH)2-MnO2//RGO
MnO2 nanotubes//AG
5.2
5.86
7.37
6.8
8.1
9
<11.4
13.5
<18
19.5
21
21
21
22.1
23.2
24
24.3
25.2
25.3
27
28.3
28.4
30.4
51.1
67.5
69.8
186
22.5
62
10
63
63
64
65
66
67,68
63
69-72
73
74
75
76
77
78
79
80
81
82
83
84
24
85
86
87
88
89
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Table S4. Relevant parameters for the asymmetric supercapacitor device including the electrode,
current collector, electrolyte, and separator. And the energy density and power density obtained
based on the mass and volume of the fully packaged cell.
Thickness (µm)
Weight (mg)
Volume (µL)
Positive electrode
(MnO2+Ni foam)
70
12.2
3.5
Negative electrode
(AG+Ni foam)
60
12.8
3.0
Separator
40
8.0
3.1
Electrolyte
6.0
Gravimetric
Emax(Wh
kg-1)
Volumetric
Pmax (kW
kg-1)
Emax (Wh L-1)
P max(kW L-1)
Active materials
(AG+MnO2)
22.5
146.2
Electrode
(AG+MnO2+Ni foam)
1.8
11.7
7.2
46.8
Full cell
（AG+MnO2+Ni foam
+Separator+Electrolyte）
1.2
7.5
5.0
31.5
The electrolyte is absorbed by the electrodes and thus does not take up any volume in the
packaged cell. With the total cell weight of 39 mg and the total cell volume of 9.6 μL, the density
of the packaged cell is estimated to be 4.2 g cm-3.
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Figure S11. Cycling performance of MnO2 nanotubes//AG asymmetric supercapacitor at the
current density of 2 A g-1. The inset shows the charge-discharge curves of the last 10 cycles of the
supercapacitor.
Figure S12. (a) The first 10 charge/discharge cycles of the MnO2 nanotubes//AG asymmetric
supercapacitor during cycling tests; (b) CV curves of the asymmetric supercapacitor after different
charge/discharge cycles at a scan rate of 50 mV s-1.
(a)
(b)
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Figure S13. SEM images of the hierarchical MnO2 nanotubes electrode in the asymmetric
capacitor after 10000 charge/discharge cycles.
b)
a)
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