17-03-2011, 02:21 PM
PRESENTED BY
CH SATYANARAYANA
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ABSTRACT
• Battery is diversified field. There exists many types of batteries and each having its own advantages and disadvantages. In the recent past, li-ion and zinc-air batteries have a made mark in the market. The applications of these batteries can be expanded with development of new techniques.
INTRODUCTION
• Battery is one or more electrochemical cells that produce direct current by converting stored chemical energy into electrical energy.
• Cell is a single unit, possibly one cell in a battery of multiple cells.
Types of cells:
galvanic,fuel,flow,voltaicpiles, electrolytic cells
Types of batteries:
rechargeable batteries non rechargeable batteries
ex: lead-acid ex: zinc-carbon
li-ion alkaline
li-polymer silver oxide
nickel-cadmium batteries lithium batteries
BATTERY CHARGER OR RECHARGER
• It is an external device that supply appropriate current
• Common types of battery chargers: mobile battery, car battery
• Common types of charging techniques:
switch mode regulator
series or linear regulator
shunt regulator
bulk regulator
pulsed charging
inductive charging
HOW TO EXTEND BATTERY LIFE:
By storing the batteries at a low temperature.
EXPLOSION:
caused by the misuse or malfunction of battery and overcharging.
LEAKAGE:
battery chemicals are poisonous. If leakage occurs, the chemicals released may be dangerous.
GENERAL BATTERY CARE:
keep the battery healthy by charging and discharging it at least once every two or three weeks.
don’t remove and carry a battery pack in your pocket or purse where metal objects like car keys could short-circuit the battery terminals.
OPERATION OF LI-AIR BATTERY:
LI-AIR BATTERY CONSTRUCTION:
• LI-AIR battery breathe oxygen from the air and allow it to react with metal anode.
• Li-air batteries are constructed in layers like a sandwich.
• It consists of li-metal anode, separator with electrolyte air cathode.
• Air cathode is critical part. At this part, oxygen enters to cells and reacts.
POUCH CELL
POUCH CELL CONSTRUCTION:
• Experimental purpose, pouch cell is used instead of li-air battery.
• It has layering components such as li-metal anode, separator with electrolyte and air cathode sealed inside the metalized plastic packets.
• Anode is composed of li-metal foil.
• Setela is used as separator. It is an organic polymer.
• 1MLiPF6 is used as electrolyte in 1:1:1 ethyl carbonate, diethyl carbonate and dimethyl carbonate.
• Air cathode is combination of carbon, metal catalyst and binder. This combination is deposited on metal current collector.
• Binder uses Teflon combined with latex.
• Metal current collector is nickel expanded with metal mesh.
AIR CATHODE PREPARATION:
• Air cathode consists of two carbon layers sandwiched around metal current collector and covered with PTFE film.
• The carbon layer consists metal catalysts.
• The layered carbon electrode is used as air cathode in li-air batteries.
• To testing the air cathodes, Li-air pouch cell is used.
LAYERED CARBON CATHODE:
ADVANTAGES OF LI-AIR BATTERIES:
• The capacity of li-air battery is ten times more capacity than li-ion batteries.
• Less weight than li-ion.
• Less cost
• Environment friendly.
COMPANIES WORKING ON LI-AIR BATTERY:
• IBM
• NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY,JAPAN
• POLYPUS BATTERY,CALOFORNIA
• ST ANDREWS UNIVERSITY
CONCLUSION:
• There are developments happening other than li-air.
• Polypus battery company working on li-sea water battery.
• Li-sea water battery can provide much more energy than li-ion.
• Li-air battery uses same technology to the li-sea water battery
• Li-sea water battery is designed for being submerged in the ocean
FUTURE EXPANSION:
• some applications might require a high current than li-air. so a
hybrid system using li-air and another energy device linked
electronically will be next battery after li-air. Hybrid li-air systems
may be developed simultaneously.