presented by msc. ir. sheilla a. odhiambo email: sheilatieno@yahoo

TEXTILE BATTERIES FOR SMART TEXTILE SYSTEMS: Comparison of silver coated yarn electrodes, pure stainless filament yarn

electrodes and copper coated yarn electrodes devices

Presented byMSc. Ir. Sheilla A. OdhiamboEmail: sheilatieno@yahoo.com

PhD student, Gent University, Department of Textiles,& Moi University , Department of MIT

THE IEK INTERNATIONAL ENGINEERING CONFERENCE AT KICC, MAY 9th -11th 2012, NAIROBI, KENYA

1. Brief introduction to Smart textile & System2. Energy storage3. Textile batteries4. Literature report highlights on smart textile

batteries/energy storage devices5. Fabricated battery/energy storage devices6. Devices fabrication and charging procedure7. Results and discussions8. Conclusion9. Acknowledgement

Contents

Smart textiles

Actuator

Interconnections

Sensor

Processing unit

Energy supply

Antenna

Smart textile system configuration

Electrochemically – Electrochemical cells (standard Battery ,1.5 Volts)

Consist of Anode, cathode, electrolyte, separators, current collectors

Electrically – Electrostatic capacitorsConsist of Conductive plates &dielectric material

Energy storage

Primary Batteries : non- rechargeable Used once and discarded Example zinc carbon batteries and alkaline batteries Have higher energy densities than rechargeable

Secondary batteries – Rechargeable◦ Applying electrical current reverse the chemical reactions that

occur during use◦ Can be used for several cycles, until its performance decline due

to wearTypes : - Wet cell : Lead acid battery, - car battery.

Gel batteries : Semisolid electrolyte to prevent spilageDry cell :Lithium ion cells used in phones and laptops

Types of batteries

Flexible

Lightweight

Comfortable

Integrated into textile matrix

Safe

Maintenance?

Why textile batteries?

PEDOT based charge storage device on a textile substrateThe PEDOT coats are placed over three, silver coated polyamide yarns interwoven in the substrate’s weft

Example of textile batteries from Literature (1) Rechargeable electronic textile battery by Bhattacharya et al 2009

Example of textile batteries from Literature (2)Lithium ion textile batteries by Hu et al 2011

Porous textile structure: Pure PET dispersed with CNT

Example of textile batteries from Literature (3)Solid electrolyte based lithium battery by Liu et al 2012

Top row: photographs of a flexible battery made of binding individual cathode, anode and polymer electrolyte filmsMiddle row: resulting battery is highly stretchable

Bottom row: battery stripes (black) woven into a textile (blue and red cotton threads) using Dobby loom. The stripes are connectorized in series with conductive threads (metallic brown)Two textile electrodes are formed by the conductive threads at the textile extremities

Example of textile based supercapacitor (4)Flexible textile supercapacitors from nanofibres by Larforgue et al 2010

C) SEM Image of Active materials (PEDOT) nanofibres, D) sem image of the separator, (PAN nanofibres)

1. Brief introduction to Smart textile & System2. Energy storage3. Textile batteries4. Literature report highlights on smart textile

batteries/energy storage devices5. Fabricated battery/energy storage device6. Device fabrication and charging procedure7. Results and discussions8. Conclusion9. Acknowledgement

Contents

A laminate of textile substrate was made from cotton/polyester (5 cm by 5 cm),

3 yarn electrodes are sewn on to the top most layer-pure stainless steel filament yarn electrodes, -copper coated yarn electrode, -silver coated yarn electrodes

The top surface is covered by TPU (Thermoplastic polyurethane, and a space 10 by 6mm left around the electrodes

PEDOT: PSS ((Poly (3,4ethylenedioxythiophene):polystyrenesulphonate) is applied here on the left space, layer by layer under the oven

The devices are charged and discharged, measured by voltage decay.

Fabricated battery/energy storage device (methodology)

Fabricated battery/energy storage device made from silver coated yarn electrodes ,and pure stainless steel filament yarns electrodes, 2011-2012 by SO

Circuit for charging & discharging the samples

Results and Discussion (1)

-sharp decrease of the voltage V in the beginning of the discharging process, as soon as the switch S is opened.

-Steel filament yarns electrode devices could hold more charge compared to the others, and copper coated yarns could barely hold the charge.

It is not surprising to learn that the charging time tch will be comparable when the discharging lasts for several hours for the active samples

Silver coated electrodes and pure stainless steel filament yarns electrodes samples can be cycled a number of times (up to10 times), comparable to the number of cycles for batteries reported by Liu et al, and Bhattacharya et al

Results and Discussions (2)

Diffusion of silver ions into PEDOT as mentioned recently in literature would not be the only responsible mechanism for the observed phenomena.

Stainless steel filament yarn performed better than the silver coated yarns electrodes and copper coated yarn electrodes.

The results motivate the making of a functional textile battery integrated within the textile structure

Conclusion

MU-VLIR UOS project for the financial support for her research and stay at the University of Gent.

Moi University management Prof. ir. Lieva Van Langenhove, and Dr. Carla Hertleer from department of

Textiles, Gent University. Prof. De Mey from the department of electronics and information systems,

Gent University. Prof. Githaiga Department of MIT Moi University. Prof. Dr.-ING. Harry L. Kaane, Higherr Education Science and Technology

secretary

Acknowledgements

Q &A Thank you