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