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TRANSCRIPT
Development of Transition
Electrodes for Super
Haoran Wu and
Department of Materials Scien
University of Toronto, Toronto, O
INTRODUCTION
Many transition metal
oxynitrides possess pseudocapaci
supercapacitors. Molybdenum oxy
materials, which is electrochem
conductive and low cost [1,2]
electrodes in supercapacitors, it is
methodology that not only can pro
molybdenum (and other transition
also can be readily scaled-up. In t
efforts on developing such proc
oxynitride electrodes.
EXPERIMENTAL
A two-step approach
Molybdenum oxides (MoO
electrodeposited onto titanium
plating bath (0.4M Na2MoO4, 0.12
H2SO4). The oxide was then conve
a thermal nitridation using nitrogen
Cyclic voltammetry was
electrochemical performance of
H2SO4 solution. For compariso
electrode without nitridation was s
RESULTS AND DISCUSSION
The cyclic voltamm
molybdenum oxide and molyb
electrodes were shown in Fig.1. Co
oxynitride exhibited a higher cap
(356F/cm3 base on an average coa
in a voltage window from -0.15V
rectangular shape of the CV for
a good capacitive behavior. Th
performance of Mo oxynitride to
the importance of the nitridation pr
The cycle life of m
electrode was shown in Fig.2, w
cycle, 2500th
cycle and 5000th
result showed little change in CV
the oxynitride electrode was stabl
in acidic media. There was a slight
from 1st cycle to 5000
th cycle (
to the further activation of the
electrolyte penetration during a rep
In addition to the pro
electrochemical characterization
morphology and structure of the p
oxynitride were also investigated
presented as well.
Transition Metal Oxynitride
for Supercapacitors
n Wu and Keryn Lian
aterials Science and Engineering,
to, Toronto, ON, Canada M5S 3E4
ition metal oxides, nitrides and
pseudocapacitive characteristics for
ybdenum oxynitride is one of these
electrochemically active, highly
[1,2]. To be applied as
pacitors, it is necessary to develop a
only can produce high performance
her transition metal) oxynitrides but
up. In this work, we report our
g such processes for molybdenum
was utilized in this study.
(MoO2, MoO3) were first
o titanium current collector in a
0.12M Na2SO4 and 0.005M
converted into oxynitride via
using nitrogen gas (99.998%).
mmetry was used to characterize the
ormance of the samples in 0.5 M
r comparison, molybdenum oxide
idation was studied as well.
CUSSION
voltammograms (CV) of
and molybdenum oxynitride on
n in Fig.1. Compare to the oxide, the
a higher capacitance of 8.2mF/cm2
average coating thickness of 230nm)
0.15V to 0.45V. The relatively
CV for Mo oxynitride suggested
havior. The superior electrochemical
xynitride to Mo oxide also illustrated
nitridation process.
of molybdenum oxynitride
in Fig.2, where the CV of the 1st
cycle were compared. The
CV profile, indicating that
de was stable for long time cycling
e was a slight increase in capacitance
cycle (ca. 6%). This may be due
tion of the bulk oxynitride through
during a repeated cycling.
to the process development and
aracterizations, the composition,
cture of the produced Mo oxide and
investigated. These results will be
REFEREN
[1] Hossein
Shokufeh M
Electrochem
[2] T.C. Liu
J. Electroch
Fig. 1 CV
oxynitride
0.45V
Fig. 2 CV
100mV/s at
REFERENCES
Hossein Farsi, Fereydoon Gobal, Heidar Raissi and
Shokufeh Moghiminia, Journal of Solid State
ectrochem 14,643 (2010)
T.C. Liu, W.G. Pell, B.E. Conway and S.L. Roberson
Electrochem. Soc. 145, 1882 (1998)
CV of molybdenum oxide vs. molybdenum
oxynitride in 0.5M H2SO4 at 100mV/s from -0.15V to
CV of molybdenum oxynitride in 0.5M H2SO4
100mV/s at 1st, 2500th and 5000th cycle.
and
.L. Roberson,
5V to
at
Abstract #84, 224th ECS Meeting, © 2013 The Electrochemical Society