SENTHIL KUMAR KANDASAMY

ASSISTANT PROFESSOR

DEPARTMENT OF ECE

KONGU ENGINEERING COLLEGE

ERODE, TAMILNADU

Investigations of Silver Zirconia Composite as

Electrode in Supercapacitor

To fabricate supercapacitor using silver-zirconia composite as one electrode and activated carbon as another electrode and to measure the capacitance using LCR meter. Silver zirconia composite was synthesized and characterized using UV Visible spectroscopy and XRD.

Finally, the supercapacitor was fabricated and measured the capacitance using LCR meter. There were two set ups created. One is single parallel plate arrangement and another one is cascading arrangement. The capacitance value is compared.

 

Abstract

Technology which deals with the various structures of matter having dimensions of the order of a billionth of a meter.

Nanotechnology

Electrochemical Double Layer Capacitor Energy is stored in supercapacitor by polarizing the electrolytic solution. Electrolytic capacitor , capacitance value limited by flat surface area and

dielectric properties Energy Density: It is the amount of energy stored per unit volume or mass. The amount of energy stored is very large because of high surface area

created by porous electrodes and the small charge separation created by separator.

Power Density: It combines energy density with the speed that energy can be drawn out of a device.

Farad: The electron storing capacity of capacitor is measured in unit Farad. One farad is approximately the charge with 6,280,000,000,000,000,000 electrons.

Advantages of the supercapacitor include high energy density compared to capacitors, High power density compared to batteries, Shorter charging time, Longer cycle life , Longer shelf life, Stability, Light weight and so on.

Introduction

Supercapacitors Higher power density Much faster charge and

discharge rate Environmentally friendly Extremely low internal

resistance or ESR High efficiency (97-98%) Over a million charge-

discharge cycles

Higher energy density Typically, 200 – 1000

charge and discharge cycles

Contains highly reactive and hazardous chemicals

Negatively effected by low temperatures

Supercapacitor Vs Batteries

Batteries

Extremely porous with a very large surface area.

Surface resembles a spongeMore electrons to be stored than other

materials.Low electronic conductivity

Activated Carbon

The specific capacitance and kinetic reversibility of the composite electrodes were enhanced by addition of silver nanoparticles.

For Zirconia, porosity in the range of 2-21% and size in the range of 65-120 nm.

The mixture was subjected to physical/chemical activation in an attempt to increase the surface area and specific capacitance of the electrode.

Silver Zirconia Composite

The silver colloids were synthesized by chemical reduction method. The CTAB was added to silver nitrate (0.1 M) solution and stirred. Then, the L-ascorbic acid (0.1 M) was added to that solution to produce silver nanoparticles. By chemical reduction silver colloids were prepared. Then, zirconium oxalate and sodium hydroxide is mixed with the silver colloid and stirred for 24 hrs to make it as a homogeneous solution. By proper sintering temperature, silver zirconia composite were obtained. This particle can dispersed in triethanolamine and water in the ratio 1:3.

Synthesis

Results and Discussion

FTIR

Wave Number, cm-1

Assignment References

1 483 Symmetric stretching mode of Zr-O-Zr bond,Zr-O vibration,Strong absorption attributed to tetragonal zirconia.Monoclinic ZrO2,O-Zr-OZr-O stretching vibration

470, V. Eswaranand and T. Pradeep, 2002.470, Luis A. P´erez-Maqueda and Egon Matijevi et al, 1997.471, Guorong Duan et al,2008506, W.T. Tang et al, 2010.400-500, Zijun Zhang et al,2011450, Zijun Zhang et al,2011

2 660 IR active fundamental mode of ZrO2 ,Asymmetric stretching mode of Zr-O-Zr bondZr-O bondSi-O-Ag bond

653, A. Sreekumaran Nair et al, 2004.650, V. Eswaranand and T. Pradeep, 2002.650, Zijun Zhang et al,2011670, Chang Sool kim et al,2008

3 797 Zr-O bond 833, Zijun Zhang et al,20114 907 Zr-O bond

Si-O-Ag bond937, Zijun Zhang et al,2011889, Chang Sool kim et al,2008

5 1110 Bending vibration of C-H 1122,Shaoxu Wang et al,20066 1288 C-C bond 1284, Zijun Zhang et al,20117 1426 Absorption bond of NO3 1387, Chang Sool Kim et al,20088 1684 Stretching vibrations of the OH groups

H-O-H bending vibrations C-O bond

1634, S. Jayakumar et al, 2011,Zijun Zhang et al, 2011.1645, Chang Sool Kim et al,20081597, Zijun Zhang et al,2011

9 3395 Bending vibrations of the OH groupsBending vibrations of the OH band due to absorbed water molecules

3419, Guorong Duan et al,20083426,S. Jayakumar et al, 2011,Zijun Zhang et al, 2011.

XRF Analysis

Element Analysis

Element Weight,%

1 Zr K 92.114

2 Si K 5.763

3 Hf L 1.306

4 Ag K 0.605

5 Ti K 0.211

Using EDX 720.

It is used to

measure the

weight

percentage of

the individual

elements.

Analysis

performed before

calcination.

XRD

Broad peak at 27

degree which

confims the

amorphous

nature of the as

prepared

composite.

AFM

Surface

roughness.

Supercapacitor setup

Electrode -

Activated Carbon

and Silver

Zirconia

Composite

Electrolyte – KI

Separator –

Whatman Paper

Asymmetric supercapacitor developed successfully using silver zirconia composite as one electrode and activated carbon as another electrode in KI electrolyte

Asymmetric supercapacitor can exhibit maximum energy density.

Two layers consisting of nanoporous electrodesSeparator is impregnated with an organic

electrolyte Thin separator can only withstand low voltages

Dielectric constant of medium X area of the plate

Capacitance = ----------------------------------

Distance between the plates

Capacitance measurement

S.No Capacitor Arrangement Electrolyte Capacitance

1 Single parallel plate capacitor KI 1 F to 12 F

2 Cascading arrangement KI 33 F to 180 F

Measured using

LCR meter.

Compared to

single parallel

plate capacitor ,

cascading

arrangement of

supercapacitor

gives the better

result.

Silver zirconia composite was synthesized and characterized using UV Visible spectroscopy and XRD. Finally, the supercapacitor was fabricated and measured the capacitance using LCR meter. For single setup the capacitance range varies between 1 F to 12 F. But for cascading arrangement the capacitance value drastically varies in between 33 F to 180 F.

Conclusion

Questions?