Supporting Information
Incorporation of Manganese Dioxide within Ultraporous Activated Graphene for High-Performance Electrochemical Capacitors Xin Zhao†,‡, Lili Zhang†, Shanthi Murali†, Meryl D Stoller, †, Qinghua Zhang‡, Yanwu Zhu,*,§ and Rodney S. Ruoff*,†
†
Department of Mechanical Engineering and the Materials Science and Engineering Program,
The University of Texas at Austin, One University Station C2200, Austin, TX 78712, ‡
State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College
of Materials Science and Engineering, Donghua University, Shanghai, 201620, P. R. China, §
Department of Materials Science and Engineering, University of Science and Technology of
China, Hefei, 230036, P. R. China. Email:
[email protected],
[email protected] 0.5
(a) o
M nO 2 Loading
Deriv. Weight (%/ C)
0.4 0.3 0.2 0.1
(b)
AGMn-5min AGMn-10min AGMn-30min AGMn-60min AGMn-90min AGMn-120min
0.0 0
40 80 Reation Time (min)
120
200
400 600 Temperature (°C)
800
Figure S1. (a) MnO2 mass uptake plotted as a function of reaction time, (b) DTG curves AGMn composites with different reaction times.
(a)
Mn 2p3/2
Intensity (a.u.)
O 2s
1000
C 2s
Mn 3s
800
600 400 200 Binding Energy (eV)
0
Intensity (a.u.)
Mn 2p
660
(b)
Mn 2p1/2
655
650 645 640 Binding Energy (eV)
635
Figure S2. (a) XPS survey spectrum of AGMn-10min, indicating the presence of Mn and O as well as C elements in composites, (b) Mn spectrum for AGMn-10min.
Figure S3. (a) High resolution SEM image of AGMn-120min nanocomposites, (b) BF-STEM image of the same area as (a), (c) SEM image combined with EDS mapping in the same area and relative intensities of C (red), Mn (green) and O (blue) elements.
Figure S4. Transmission electron micrographs for AGMn-10min-h with different magnifications
20 0
-20 10mV/s 50mV/s 100mV/s 200mV/s
-40
0.0
0.2
0.4
0.6
Potential (V)
0.8
(b)
AGMn-120min 1.0
Potential (V)
Current Density (A/g)
(a)
AGMn-120min
40
1A/g (220F/g) 2A/g (212F/g) 5A/g (198F/g) 10A/g(192F/g)
0.8 0.6 0.4 0.2 0.0
1.0
0
50
Time (s)
100
Figure S5. (a) Cyclic voltammograms and(b) charge-discharge curves with different rates for AGMn-120min composites.
1.2V 1.4V 1.6V 1.8V 2.0V
8
4
20
(a)
20mV/s
Current Density (A/g)
Current Density (A/g)
12
0
-4
(b)
20mV/s 1.0V 1.2V 1.4V
15 10 5 0 -5
1M H2SO4
-10
0.0
0.5
1.0
Voltage (V)
1.5
2.0
0.0
0.5
1.0
1.5
Voltage (V)
Figure S6. (a) CV curves of an optimized AGMn// aMEGO asymmetric supercapacitor measured at different potential windows in 1M Na2SO4 aqueous solution (b) and 1M H2SO4 aqueous solution at a scan rate of 20 mV/s.
