CHONNAM NATIONAL UNIVERSITYCHONNAM NATIONAL UNIVERSITY

SnO2 and Cobalt doped SnO2 materials were prepared using low

temperature hydrothermal method.

XRD reveals that the substitution of Co affects the crystal

structure of SnO2 and increases the crystallization of the materials.

TEM images shows that SnO2 and Sn1-xCoxO2 particles are well

developed and have spherical morphology with an average size of

2-4 nm.

Cyclic voltammetry curves show rectangular-like shape which

reveals the capacitive behavior of the materials.

Maximum capacitance of 840 F/g is obtained from Sn0.6Co0.4 O2 in

1 M H2SO4 recorded at 10 mV/s scan rate.

ConclusionsConclusions Aim of the workAim of the work

IntroductionIntroduction

AdvantagesAdvantages

Virtually unlimited cycle life

Low impedance

Simple charge methods

Cost-effective energy storage

DisadvantagesDisadvantages

Unable to use the full energy

spectrum

Low energy density

Cells have low voltages

High self discharge

Supercapacitors (ECs) or ultracapacitors are being widely used for energy storage

in many applications, such as portable electronic devices, and electrical vehicles

etc.

The supercapacitor resembles a regular capacitor except that it offers very high

capacitance in a small package.

Classification of ECsClassification of ECs

Electrochemical double Electrochemical double layer capacitor (EDLC)layer capacitor (EDLC)

Stores energy by double layer, which is formed by the charge separation between the electrode/electrolyte interface

Electrode materials – high surface area carbon such as Activated carbon, Carbon aerogel, Carbon mat, etc.

Redox capacitors (RC)Redox capacitors (RC)

Stores energy by utilizing the pseudocapacitance, which is arising from the redox reactions of active materials

Metal oxides – NiO, MnO2, IrO2 and RuO2

Conducting polymers: PANI, Polythiophene etc.

Among all of the electrode materials, RuO2 exhibits a higher specific capacitance,

good electrical conductivity and stability. However, the high cost and scarce material

retarded its commercial acceptance

A cheap material with equivalent performance is required. Transition metal oxides

have been considered as promising materials for supercapacitors.

To replace RuO2 with cheap

transition metal oxide.

Cobalt doped tin oxide

simples have been synthesized

by hydrothermal method for

supercapacitor application.

Supercapacitive behavior of

Sn1-xCoxO2 samples were

evaluated by cyclic

voltammogram (CV) in 1 M

H2SO4 recorded at 10 mV/s

scan rate.

Stoichiometric amount of

SnCl2 and CoCl2 in 50 ml 0.1 M

NaOH solution and stirred

Add 10 ml ethylene glycol

followed by heating to dissolve

Transferred to teflon autoclave

and heated at 180 0C for 24h.

Sn1-xCoxO2 particles were

separated by centrifuge and

dried at 600 C for 12h

20 30 40 50 60 70 80

SnO2

2 theta (deg)

Sn0.8

Co0.2

O2

Sn0.6

Co0.4

O2

Sn0.4

Co0.6

O2

Sn0.2

Co0.8

O2

(11

2)(

30

1)

(21

1)

(20

0)

(10

1)

(11

0)

Inte

nsi

ty (

A.U

)

Results and discussionResults and discussion

1000 800 600 400

SnO2

% T

ran

smitt

an

ce

Wavenumbers (cm -1)

Sn0.8

Co0.2

O2

Sn0.6

Co0.4

O2

Sn0.4

Co0.6

O2

Sn0.2

Co0.8

O2

The intensity of the diffraction peaks increases with the

increase in the Co content, which indicates the

enhancement of the crystallization of the materials

The peaks observed at 650, 603, 561 are

typical for Sn-O stretching vibrations.

Similarly the peak at 483 cm-1 corresponds to

the Co-O-Co stretching mode, which is not

available for the bare SnO2.

(a) - SnO2

(b) - Sn0.8Co0.2O2

(c) - Sn0.6Co0.4O2

(d) - Sn0.4Co0.6O2

(e) - Sn0.2Co0.8O2

Effect of cobalt addition of SnOEffect of cobalt addition of SnO22 nanoparticles by using hydrothermal nanoparticles by using hydrothermal

method and its capacitor applicationsmethod and its capacitor applications

K. KarthikeyanK. Karthikeyan11, D. Kalpana, D. Kalpana22, S.B. Lee, S.B. Lee11, I.C. Jang, I.C. Jang11, H.H. Lim, H.H. Lim11, Y.S. Lee, Y.S. Lee11

11 Faculty of Applied Chemical Engineering, Chonnam National University, Gwangju 500-757, Republic of KoreaFaculty of Applied Chemical Engineering, Chonnam National University, Gwangju 500-757, Republic of Korea

22 Central Electrochemical Research Institute, Karaikudi 630 006, India Central Electrochemical Research Institute, Karaikudi 630 006, India

When the Co content

increased from 0.2 to 0.8 the

particle sizes decreased

from 2.59 nm to 2.36 nm.

The doping of Co in SnO2

has an influence on the

crystallite size and the

addition of Co decreases the

growth of the crystalline

grains of SnO2.

-0.8 -0.6 -0.4 -0.2 0.0

-18

-15

-12

-9

-6

-3

0

3

6

9

12

SnO2

Sn0.8

Co0.2

O2

Sn0.6

Co0.4

O2

Sn0.4

Co0.6

O2

Sn0.2

Co0.8

O2

Cur

rent

(A

g-1)

Potential (V)

The cyclic voltammogram of

pure and Co-doped SnO2 in 1

M H2SO4 recorded at 10 mV/s

scan rate.

From the CV, a maximum

capacitance of 840 F/g was

obtained for the Sn0.6Co0.4 O2.

XRD patternsXRD patterns

FTIR spectrum

TEM imagesTEM images

Cyclic Voltammetry studiesCyclic Voltammetry studies

PreparationPreparation