rechargeable batteries with conductive polymer

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Rechargeable Batteries

Rechargeable Batteries

Presented byDevansh GuptaM.Sc Polymer ScienceSemester 1


Contents IntroductionWhy Do We Need Batteries?Electrodes & ElectrolytesBrief History About BatteriesTypes Of BatteryWhat If We Use Conducting Polymer In Rechargeable BatteriesSafety Issues Reference

IntroductionBattery Is Nothing But A Device Which Converts Stored Chemical Energy Into Electrical Energy.It Is Made Up Of Two Electrodes (Anode & Cathode) And Electrolyte Solution.Here Oxidation & Reduction Reactions Are Simultaneously Happens Between These Two Electrodes, Which Create The Current Flow.When A Battery Is Supplying Current, Its +Ve Terminal Is Denoted As Cathode & Its Ve Terminal Is Denoted As Anode

Symbol of battery in a circuit diagram

Why Do We Need Batteries?


Electrodes & Electrolytes

CathodePositive terminal Electrochemical reduction occurs (gain electrons)AnodeNegative terminalElectrochemical oxidation occurs (lose electrons)Electrolytes Allow Ions to move between electrodes and terminalsAllows Current to flow out of the battery to perform work

Brief History About BatteriesIn 1749, Benjamin Franklin first used the term battery to describe a set of linked capacitors he used for his experiments with electricity.In 1800, Alessandro Volta invented the first true battery, which came to know as the voltaic pile.The voltaic pile consist a pair of silver and zinc discs placed on each other which is separated by a layer of cloth soaked in brine (Brine as Electrolyte) Unlike the Leyden Jar, the voltaic pile produced a stable & continuous current, and lost little charge over time when not in use.Early models of voltaic pile cant produce strong current to generate sparks.


Benjamin Franklin 6th President of Pennsylvania..In 1750 He published a proposal for an experiment to prove that lightning is electricity by flying a kite in a stormIn 10th May, 1752 a French Scientist conducted his experiment using a 40ft tall iron rod instead of a kite and he extracted electrical sparks from cloud.. Leyden Jar Its a device that stores static electricity between two electrodes on the inside and outside of a glass jar.. A typical Leyden jar consist of a glass jar with metal foil cemented to the inside and outside wall of glass jar Here a metal terminal inserted vertically through the jar lid to make contact with the inner foil.. It was the original form of capacitor.. This name was given on the name of a city..


1800 Voltaic Pile: Silver Zinc1836 Daniell Cell: Copper Zinc1859 Plant: Rechargeable Lead-acid Cell1868 Leclanch: Carbon Zinc Wet Cell1888 Gassner: Carbon Zinc Dry Cell1898 Commercial Flashlight, D Cell1899 Junger: Nickel Cadmium Cell1946 Neumann: Sealed Ni-Cd1960 Alkaline, Rechargeable Ni-Cd1970 Lithium, Sealed Lead Acid1990 Nickel metal hydride (NiMH)1991 Lithium ion1992 Rechargeable alkaline1999 Lithium ion polymer

Voltaic Pile

Types Of BatteryBasically batteries can be classifieds as two types as primary batteries and secondary batteries.

Primary Battery(disposable) In primary batteries, the electrochemical reaction is not reversible. Used when long periods of storage are required.During discharging the chemical compounds are permanently changed and electrical energy is released until the original compounds are completely exhausted. Lower discharge rate than secondary batteries.Thus the cells can be used only once.

Examples Of Primary BatteriesZinc Carbon Used in flashlights, toysHeavy Duty Zinc Chloride Used in radios, recordersAlkaline Used in all of the aboveLithium Used in photoflashSilver Mercury Oxide Used in Hearing aid, watches, calculators

Zinc Carbon Battery

This kind of batteries are generally used in flashlights and toys

ChemistryZinc (-ve), Manganese Dioxide (+ve)Zinc Chloride and Ammonium Chloride paste as electrolyteFeaturesInexpensive, widely available.Inefficient at high current drain.Poor discharge curve (sloping).Poor performance at low temperatures.

Zinc Carbon Battery

Heavy Duty Zinc Chloride Batteries

This kind of batteries are generally used in radios and recorders.

Chemistry Zinc (-ve), manganese dioxide (+ve) Zinc chloride aqueous electrolyteFeatures (compared to Zinc Carbon)Better resistance to leakage.Better at high current drain.Better performance at low temperature.

Alkaline BatteriesThis kind of batteries are generally used in toys, radios, recorders and flashlights.

Chemistry Zinc (-ve), manganese dioxide (+ve)Potassium hydroxide aqueous electrolyteFeatures 50-100% more energy than carbon zincLow self-discharge (10 year shelf life)Good for low current (< 400mA), long-life usePoor discharge curve

Alkaline Battery

Secondary Battery(Rechargeable)

In secondary batteries, the electrochemical reaction is reversible. Used when short periods of storage are required.During discharging the chemical compounds which are changed can be reconstituted by the application of an electrical potential between the electrodes.Higher discharge rate than primary batteries.Thus such cells can be Rechargeable and used many times.

Some Examples Of Secondary Batteries

Nickel Cadmium BatteryNickel Metal Hydride BatteryLead Acid BatteryLithium Ion Battery

Nickel Cadmium Batteries

ChemistryCadmium (-ve), nickel hydroxide (+ve)Potassium hydroxide aqueous electrolyteFeaturesRugged, long life, economicalGood high discharge rate (for power tools)Relatively low energy densityToxic

First Ni-Cd cell was created by Waldemar Jungner in 189918

Cell Reaction Of Ni-Cd BatteryThe half-reactions are:Cd+2OH- Cd(OH)2+2e-2NiO(OH)+Cd+2e- 2Ni(OH)2+2OH-

Overall reaction:2NiO(OH) + Cd+2H2O2Ni(OH)2+Cd(OH)2

Advantages Of Ni-Cd Batteries

Available in different size and shapes.Have ability to deliver full power output until end of cycleVery low internal resistanceSimple and fast to recharge Over 1000 cycles (if properly maintained)Operate in a range of temperatures.Tolerates abuse well and performs well after long periods of storage.

Disadvantages Of Ni-Cd Batteries

It is three to five times more expensive than lead-acidSelf discharge up to 10% in a day.Its materials are toxic and the recycling infrastructure for larger nickel-cadmium batteries is very limited.

Uses Of Ni-Cd BatteryNi-Cd batteries may be used individually or assembled into battery packs containing two or more cells.Specially Ni-Cd batteries are used in cordless and wireless telephones, emergency lighting and other applications.With a low internal resistance, they can supply a high surge current. This makes them a favourable choice for remote controlled model airplanes, boats, cars and camera flash units.

Lead Acid BatteryChemistryLeadSulfuric acid electrolyte

FeaturesLeast expensiveDurableLow energy densityToxic

Cell Reaction Of Lead Acid BatteryDischarging(+) electrode: PbO2(s) + 4H+(aq) + SO42-(aq) + 2e- PbSO4(s) + 2H2O(L)(-) electrode: Pb(s) + SO42-(aq) PbSO4(s) + 2e-Charging(+) electrode: PbSO4(s) + 2H2O(L) PbO2(s) + 4H+(aq) + SO42-(aq) + 2e- (+) electrode: PbSO4(s) + 2e- Pb(s) + SO42-(aq)

Advantages Of Lead Acid BatteriesLow maintenance requiredAvailable in all shapes and sizes.Best in terms of reliability & working capabilities.Withstand slow, fast & overcharging.Capable to withstand long term inactivity with or without solvent.Have the longest life cycle and a large environmental advantage.97% of the lead is recycled and reused in new batteries.

Disadvantages Of Lead Acid BatteriesLimited number of full discharges.Danger of overheating during charging.In some cases it may releases acid fumes, which can cause numerous health issues in terms of long time exposure.Corrosion may decrease battery life, so must be avoided through proper maintenance.

Lead Acid Battery UsesThe lead-acid cells in automobile batteries are wet cells.Deliver short burst of high power, to start the engine.Battery supplies power to the starter and ignition system to start the engine.Supplies the extra power necessary when the vehicle's electrical load exceeds the supply from the charging system.

Lithium Ion BatteryChemistryGraphite (-ve), Lithium cobalt dioxide (+ve) Non aqueous electrolyte

Features40% more capacity than Ni-CdFlat discharge (like Ni-Cd)Self-discharge 50% lesser than Ni-CdExpensive

Charging Phenomena

AL CurrentCollectorCu CurrentCollectorElectrolyteLiCoO2GraphiteLithium-Ion BatteryCharging

AL CurrentCollectorCu CurrentCollectorElectrolyteLiMO2GraphiteLithium-Ion BatteryDischarging

Advantages Of Lithium Ion BatteryThe most distinct advantage is high energy density.Lower self discharge rate. (In comparison with Ni-Cd Battery)No maintenance.No memory effect.No requirement for priming.Variety of types available.

Disadvantages Of Lithium Ion BatteryRequire protection from overcharge & fully discharge.Shows ageing.Transportation by air is sometimes difficult.40% more costly than Ni-Cd batteries.No established system for recycling large lithium-ion batteries.

Uses Of Lithium Ion Batteries

What If We Use Conducting Polymers In BatteriesAdvantagesLonger cyclic timehigh discharge timeLess self discharge timeFlexible shapeEasy fabrication of component in film formDisadvantageCost

The Safety Issue R. Crompton, Battery Reference Book, Newnes, 2000D. Berndt, Maintenance-Free Batteries, Wiley, 1997C. Vincent & B. Scrosati, Modern Batteries, Wiley, 1997