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RSC Advances
XRD patterns were collected on a PW3040/60 X’ Pert
Acknowledgment
PRO (PANalytical) diffractometer equipped with a Cu Kα
radiation source (λ = 0.15432 nm), operating at 40 kV, 40 mA
for wide angle and 40 kV, 30 mA for low angle, respectively.
A continuous mode was used for collecting data in the 2θ
range from 10 to 80 for wide angle and from 0.5 to 4.5
for low angle.
We gratefully acknowledge the financial support of the
National Basic Research Program of China (2009CB226102).
5
o
o
o
o
60 Notes and references
a State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics,
Chinese Academy of Science, PO Box 110, Dalian,116023, P. R. China. E-
mail: taozhang@dicp.ac.cn. Fax:+86-411-84691570; Tel:+86-411-
TEM images were obtained on a Philips CM200 LaB6
microscope operating at 200 kV, and EELS spectrum and energyꢀ
84379015
;
10 filtered images were obtained on a FEI Csꢀcorrected Titan 80ꢀ300
microscope operating at 80.0 kV. The HAADFꢀSTEM, and EDS
mapping were carried out on a FEI Tecnai G2 F20 microscope
operating at 200 kV. The sample was ultrasonically dispersed in
ethanol, and then a drop of the solution was deposited on a holey
15 C/Cu TEM grid to be used for TEM, STEM and EELS
characterization.
XPS was conducted on ESCALAB250 (Thermo VG
Corporation) equipped with a Al Kα radiation (1486.6 eV, 15
kV, 10 mA, 150W). All binding energies were calibrated with
20 graphitic carbon C1s peak at BE of 284.5 eV as a reference.
The recorded spectra were fitted by a least square procedure
65 b Beijing Key Laboratory of Green Chemical Reaction Engineering and
Technology, Department of Chemical Engineering, Tsinghua University,
Beijing 100084, P. R. China
.c Shenyang National Laboratory for Materials Science Institute of Metal
Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016,
70 P. R. China. E-mail: dssu@imr.ac.cn
d
Key Laboratory of Carbon Materials, Institute of Coal Chemistry, Chinese
Academy of Sciences, Taoyuan South Road 27, Taiyuan 030001, P.R. China
e
Graduate University of Chinese Academy of Science, Beijing 100049, P. R.
China.
75 † Electronic Supplementary Information (ESI) available: Proposed synthesis
scheme, XPS, and TEM images of BxꢀOMC. See DOI: 10.1039/b000000x/
to
a
product of GaussianꢀLorentzian functions after
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subtraction of background noise. The concentration of each
element was calculated from the area of the corresponding
25 peak calibrated with the atomic sensitivity factor.
80
S. B. Lee, Chem. Commun., 2011, 47, 1384.
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4. 3 Electrochemical measurements
For preparing a working electrode, a mixture of an active
material, carbon black and poly(tetrafluoroethylene) with a
85
weight ratio of 90:5:5 was ground together to form
a
30 homogeneous slurry. The slurry was squeezed into a film and
then punched into pellets with a surface area of 1.0 cm2 for each
piece. The punched pellets with a nickel foam on each side was
pressed under 6.0 MPa for 1.0 min and dried overnight at 120 oC.
Prior to the electrochemical tests, the electrodes were
35 impregnated with electrolyte under vacuum for several hours.
The CV tests were conducted using Zahner Elektrik IM6e
electrochemical workstation in a threeꢀelectrode cell system, in
which a sintered Ni(OH)2/NiOOH as the counter electrode, a
Ag/AgCl as the reference electrode and a 6.0 M KOH solution as
40 the electrolyte. A scan rate of 2, 5, 10, 20, 50, and 100 mV sꢀ1 was
applied respectively in the CV studies. The GC measurement was
conducted on automatic LAND battery test instrument
(CT2001A) to elvaluate the charge/discharge performance and a
current of 0.2 A gꢀ1 current was applied in GC studies.
90
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95
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100
45
The specific capacitance of a single electrode (Celec) was
calculated from the CV curves based on the equation,
Celec= idt/dv
where i is the instant current in Amperes per gram of active
material and dv/dt is the scanning rate in Volts per second.
The specific capacitance of the cell (Ccell) was calculated
from GC profiles based on the following equation,
Ccell= (I: t)/: U
where I is the discharge current in Amperes per gram of
active material, t is the discharge time in second, and U is the
55 voltage window from the end of the IR drop to the end of the
discharge process in Volts.
105 8. C. MorenoꢀCastilla, M. B. Dawidziuk, F. CarrascoꢀMarin and Z. Zapataꢀ
Benabithe, Carbon, 2011, 49, 3808.
50
9. P. Mohanty and K. Landskron, J. Mater. Chem., 2009, 19, 2400.
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110
Selvan, D. P. Sawant, M. A. Chari, G. Q. Lu and A. Vinu, Angew. Chem.
Int. Ed., 2009, 48, 7884
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Science, 2008, 322, 73
6
| RSC Adv., 2012, [vol], 00–00
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