CHAPTER 1INTRODUCTION TO PAPER BATTERY1.1 INTRODUCTION TO ORDINARY BATTERY:Ordinary paper could one day be used as a lightweight battery to power the devices that are now enabling the printed word to be eclipsed by e-mail, ebooksan online news. Scientists at Stanford University in California reported on Monday they have successfully turned paper coated with ink made of silver and carbon nano materials into a "paper battery" that holds promise for new types of lightweight, high-performance energy storage. The same feature that helps ink adhere to paper allows it to hold onto the single-walled carbon nanotubes and silver nano wire films. Earlier research found that silicon nano wires could be used to make batteries 10 times as powerful as lithium-ion batteries now used to power devices such as laptop computers.Figure 1.1.1:ordinary battery "Taking advantage of the mature paper technology, low cost, light and highperformance energy-storage are realized by using conductive paper as current collectors and electrodes," the scientists said in research published in the Proceedings of the National Academy of Sciences. This type of battery could be useful in powering electric or hybrid vehicles, would make electronics lighter weight and longer lasting, and might even lead someday to paper electronics, the scientists said. Battery weight and life havebeen an obstacle to commercial viability of electric-powered cars and trucks."Society really needs a low-cost, high-performance energy storage device, such as batteries and simple super capacitors," Stanford assistant professor of materials science and engineering and paper co-author Yi Cui said. Cui said in an e-mail that in addition to being useful for portable electronics and wearable electronics, "Our paper supercapacitors can be used for all kinds of applications that require instant high power.

Figure 1.1.2 Conventional battery "Since our paper batteries and super capacitors can be very low cost, they are also good for grid-connected energy storage," he said. Peidong Yang, professor of chemistry at the University of California Berkeley, said the technology could be commercialized within a short time. 1.2 INTRODUCTION OF PAPER BATTERY A paper battery is a flexible, ultra-thin energy storage and production device formed by combining carbon nanotube with a conventional sheet of cellulose-based paper. A paper battery acts as both a high-energy battery and super capacitor , combining two components that are separate in traditional electronics . This combination allows the battery to provide both long-term, steady power production and bursts of energy. Non-toxic, flexible paper batteries have the potential to power the next generation of electronics, medical devices and hybrid vehicles, allowing for radical new designs and medical technologies.

Figure 1.2.1 carbon nanotubes Paper batteries may be folded, cut or otherwise shaped for different applications without any loss of integrity or efficiency . Cutting one in half halves its energy production. Stacking them multiplies power output. Early prototypes of the device are able to produce 2.5 volt s of electricity from a sample the size of a postage stamp.

Figure 1.2.2 paper battery The devices are formed by combining cellulose with an infusion of aligned carbon nanotubes that are each approximately one millionth of a centimeter thick. The carbon is what gives the batteries their black color. These tiny filaments act like the electrode s found in a traditional battery, conducting electricity when the paper comes into contact with an ionic liquid solution. Ionic liquids contain no water, which means that there is nothing to freeze or evaporate in extreme environmental conditions. As a result, paper batteries can function between -75 and 150 degrees Celsius. One method of manufacture, developed by scientists at Rensselaer Polytechnic Institute and MIT, begins with growing the nanotubes on a 6 silicon substrate and then impregnating the gaps in the matrix with cellulose. Once the matrix has dried, the material can be peeled off of the substrate, exposing one end of the carbon nanotubes to act as an electrode .

Figure 1.2.3 paper battery When two sheets are combined, with the cellulose sides facing inwards, a super capacitor is formed that can be activated by the addition of the ionic liquid. This liquid acts as an electrolyte and may include salt-laden solutions like human blood, sweat or urine. The high cellulose content (over 90%) and lack of toxic chemicals in paper batteries makes the device both biocompatible and environmentally friendly, especially when compared to the traditional lithium ion battery used in many present-day electronic devices and laptops. Widespread commercial deployment of paper batteries will rely on the development of more inexpensive manufacturing techniquesfor carbon nanotubes. As a result of the potentially transformative applications in electronics, aerospace, hybrid vehicles and medical science, however, numerous companies and organizations are pursuing the development of 7 paper batteries. In addition to the developments announced in 2007 at RPI and MIT, researchers in Singapore announced that they had developed a paper battery powered by ionic solutions in 2005. NEC has also invested in R & D into paper batteries for potential applications in its electronic devices. Specialized paper batteries could act as power sources for any number of devices implanted in humans and animals, including RFID tags, cosmetics, drug-delivery systems and pacemakers. A capacitor introduced into an organism could be implanted fully dry and then be gradually exposed to bodily fluids over time to generate voltage. Paper batteries are also biodegradable, a need only partially addressed by current e-cycling and other electronics disposal methods increasingly advocated for by the green computing movement.

CHAPTER 2MANUFACTURING OF PAPER BATTERY2.1 MANUFACTURING OF CARBON NANOTUBES:One method of manufacture, developed by scientists at Rensselaer Polytechnic Institute and MIT, begins with growing the nano tubes on a silicon substrate and then impregnating the gaps in the matrix with cellulose. Once the matrix has dried, the material can be peeled off of the substrate, exposing one end of the carbon nano tubes to act as an electrode .

Figure 2.1 paper batteryWhen two sheets are combined, with the cellulose sides facing inwards, a super capacitor is formed that can be activated by the addition of the ionic liquid. This liquid acts as an electrolyte and may include salt-laden solutions like human blood, sweat or urine. The high cellulose content (over 90%) and lack of toxic chemicals in paper batteries makes the device both biocompatible and environmentally friendly, especially when compared to 9 the traditional lithium ion battery used in many present-day electronic devices and laptops. Specialized paper batteries could act as power sources for any number of devices implanted in humans and animals, including RFID tags, cosmetics, drug-delivery systems and pacemakers. A capacitor introduced into an organism could be implanted fully dry and then be gradually exposed to bodily fluids over time to generate voltage. Paper batteries are also biodegradable, a need only partially addressed by current e-cycling and other electronics disposal methods increasingly advocated for by the green computing movement. 2.2 DEVELOPMENT: The creation of this unique nano composite paper drew from a diverse pool of disciplines, requiring expertise in materials science, energy storage, and chemistry. The researchers used ionic liquid, essentially a liquid salt, as the batterys electrolyte. The use of ionic liquid, which contains no water, means theres nothing in the batteries to freeze or evaporate. This lack of water allows the paper energy storage devices to withstand extreme temperatures, Kumar said. It gives the battery the ability to function in temperatures up to 300 degrees Fahrenheit and down to 100 below zero. The use of ionic liquid also makes the battery extremely biocompatible; the team printed paper batteries without adding any electrolytes, and demonstrated that naturally occurring electrolytes in human sweat, blood, and urine can be used to activate the battery device. 10 Cellulose-based paper is a natural abundant material, biodegradable, light, and recyclable with a well-known consolidated manufacturing process. These attributes turn paper a quite interesting material to produce very cheap disposable electronic devices with the great advantage of being environmental friendly. The recent (r) evolution of thin-film electronic devices such as paper transistors [1], transparent thin-film transistors based on semiconductor oxides [2], and paper memory [3], open the possibility to produce low cost disposable electronics in large scale. Common to all these advances is the use of cellulose fiber-based paper as an active material in opposition to other ink-jet printed active-matrix display [4] and thin-film transistors [5] reports where paper acts only as a passive element (substrate). Batteries in which a paper matrix is incorporated with carbon nanotubes [6], or biofluid - and water-activated batteries with a filter paper [7] have been reported, but it is not known a work where the paper itself is the core of the device performance.Figure 2.2 development of paper battery With the present work, we expect to contribute to the first step of an incoming disruptive concept related to the production of self-sustained paper electronic systems where the power supply is integrated in the electronic circuits to fabricate fully self sustained disposable, flexible, low cost and low electrical consumption systems such as tags, games or displays. In achieving such goal we have fabricated batteries using commercial paper as electrolyte and physical support of thin film electrodes. A thin film layer of a metal or metal oxide is deposited in one side of a commercial paper sheet while in the opposite face a metal or metal oxide with opposite 12 electrochemical potential is also deposited. The simplest structure produced is Cu/paper/Al but other structures such as Al paper WO TCO were also tested, leading to batteries with open circuit voltages varying between 0.50 and 1.10 V. On the other hand, the short current density is highly dependent on the relative humidity (RH), whose presence is important to recharge the battery. The set of batteries characterized show stable performance after being tested by more than 115 hours, under standard atmospheric conditions [room temperature, RT (22 C) and 60% air humidity, RH]. In this work we also present as a proof of concept a paper transistor in which the gate ON/OFF state is controlled by a non-encapsulated 3 V integrated paper battery.

CHAPTER 3EXPERIMENTAL DETAILS3.1 EXPERIMENTAL DETAILSThe paper batteries produced have the Al/paper/Cu structure, where the metal layers were produced by thermal evaporation at RT. The thicknesses of the metal elect rodes varied between 100 and 500 nm. The electrical characteristics of the batteries were obtained through IV curves and also by sweep voltammetry using scanning speed of 25 mV/s and the electrodes area of 1 cm . A Keithley 617 Programmable Electrometer with a National Instruments GPIB acquisition board were used to determine the IV characteristics.

Figure 3.1 Dependence of temperature on discharge capacity

The cyclic voltammetry was performed with a potenciostatGamry InstrumentsRef. 600 in a two-electrode configuration. The electrical performances of the batteries were determined by monitoring the current of the battery under variable RH conditions. The surface analysis of the paper and paper batteries was performed by S-4100 Hitachi scanning electron microscopy (SEM), with a 40 tilt angle. The electrical properties of the paper transistor controlled by the paper battery were monitored with an Agilent 4155C semiconductor parameter analyzer and a Cascade M150 microprobe station.

Figure 3.2 Typical series connection method

Chapter-4ADVANTAGES & APPLICATIONS4.1 IN COSMETICS Anti-aging and wrinkles Dark spots / Discoloration Skin lightening / Whitening Firming and lifting Moisturizing

Figure 4.1.1Anti-aging and wrinkles

Fig 4.1.2 LG Ion Patch (For whitening)

Figure 4.1.3 Iontophoresis mechanism

Figure 4.1.4 estee lauder (for wrinkles)

4.2 USES OF PAPER BATTERYThe paper-like quality of the battery combined with the structure of the nanotubes embedded within gives them their light weight and low cost, 25 making them attractive for portable electronics, aircraft, automobiles, and toys (such as model aircraft), while their ability to use electrolytes in blood make them potentially useful for medical devices such as pacemakers. The medical uses are particularly attractive because they do not contain any toxic materials and can be biodegradable; a major drawback of chemical cells However, Professor Sperling cautions that commercial applications may be a long way away, because nanotubes are still relatively expensive to fabricate. Currently they are making devices a few inches in size. In order to be commercially viable, they would like to be able to make them newspaper size; a size which, taken all together would be powerful enough to power a car.

4.3 DURABILITY The use of carbon nanotubes gives the paper battery extreme flexibility; the sheets can be rolled, twisted, folded, or cut into numerous shapes with no loss of integrity or efficiency, or stacked, like printer paper (or a Voltaic pile), to boost total output. As well, they can be made in a variety of sizes, from postage stamp to broadsheet. Its essentially a regular piece of paper, but its made in a very intelligent way, said Linhardt, Were not putting pieces together its a single, integrated device, he said.

Future scopeFinding ways to increase battery capacity has been a prior task of many research teams around the world. This is especially the case with paper based Li-ion batteries, due to their flexibility and relatively low cost. Now a team from Arizona State University have discovered that by folding these batteries, the energy density and capacity is increased 14 times.

Fig folding a paper battery The study published in the latest issue of Nano Letters with a lead author Qian Cheng, reveals howfolding batteries can be used to power future folding electronic devices, or provide energy supply in limited spaces.conventional lithium-based powders. The new addition was a coating made of polyvinylidene difluoride (PVDF), which was applied in order to straighten the attraction between the ink and the paper substrate. The team measured the battery conductivity and stable capacity, before experimenting with different folding.To establish the performance characteristics after folding, the team used areal density, which is essentially the energy density per foot print area. They found that the more complicated the folding, and the higher the number of folds, the greater the areal energy density capacity. In this sense, the highest energy density and capacity for the smallest total area, were measured when the battery is folded in a Miura-ori pattern into a stack of 25 layers.Folding the batteries by using simple patterns did not improve the performance greatly in comparison with planar batteries. The team noted that the Coulombic efficiency of the folded batteries was higher, which could be due to the better contact between the electrodes and the ink. Folding the batteries in the Miura-ori pattern, resulted in a lower discharge capacity, which the researchers explain with the delamination at the intersections of perpendicular folds.The team is very proud of their findings, as these reveal great potential for future mass production of high areal energy density and capacity Li-ion batteries, which can power small or folding electronic devices. The researchers are now testing different and more complex folding patterns, which could open up the scope of using paper-based energy storage for new and exciting applications.

CONCLUSIONIn this paper we show the functionality of a non-encapsulated thin-film battery using paper as electrolyte and also as physical support. Batteries able to supply a Voc.70V and Jsc>100nA/cm2 at RH>60% were fabricated using respectively as anode and cathode thin metal films of Al and Cu as thin as 100 nm. The battery is self rechargeable when exposed to relative humidity above 40%, being Jsc highly influenced by RH>60%. In this case,Jsc varies from 150 nA/cm2 to 0.8 mA/cm2 , as RH varies from 60% to 85%. This constitutes the first step towards future fully integrated self sustained flexible, cheap and disposable electronic devices, with great emphasis on the so-called paper electronics.

references[1] E. Fortunato, N. Correia, P. Barquinha, L. Pereira, G. Goncalves, and R. Martins, High-performance flexible hybrid field-effect transistors based on cellulose fiber paper, IEEE Electron Device Lett., vol. 29, no. 9, pp. 988 990, Sep. 2008. [2] E. Fortunato, A. Goncalves, A. Pimentel, P. Barquinha, G. Goncalves, L. Pereira, I. Ferreira, and R. Martins, Zinc oxide, a multifunctional material: From material to device applications, Appl.Phys.Materials Science & Processing, vol. 96, pp. 197206, Jul. 2009. [3] R. Martins, P. Barquinha, L. Pereira, N. Correia, G. Gonalves, I. Ferreira, and E. Fortunato, Write-erase and read paper memory transistor, Appl. Phys. Lett., vol. 93, p. 203501, Nov. 2008.[4] P. Andersson, D. Nilsson, P.-O.Svensson, M. Chen, A. Malmstrom, T. Remonen, T. Kugler, and M. Berggren, Active matrix displays based on allorganic electrochemical smart pixels printed on paper, Adv. Mater., vol. 14, no. 20, pp. 14601464, Oct. 2002. [5] J. Sun, Q.Wan, A. Lu, and J. Jiang, Low-voltage electric-double-layer paper transistors gated by microporousSiO processed at room temperature, Appl. Phys. Lett., vol. 95, pp. 222108-1222108-3, Nov. 2009. [6] V. L. Pushparaj, M. M. Shaijumon, A. Kumar, S. Murugesan, L. Ci, R. Vajtai, R. J. Linhardt, O. Nalamasu, and P. M. Ajayan, Flexible energy storage devices based on nanocomposite paper, PNAS, vol. 104, no. 4, pp. 1357413577, Aug. 2007. [7] K. B. Lee, Two-step activation of paper batteries for high power generation: Design and fabrication of biofluid- and water-activated paper batteries, J. Micromech. Microeng., vol. 16, pp. 23122317, Sept. 2006.

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