Presantation on working of batteries

Submitted by: Ardit Meti & Erdoan Muca

What is BATTERY?

A system which converts chemical energy into electrical energy.

More correctly, a battery is an electrochemical cell:Galvanic CellsElectrolytic Cells

HISTORY OF BATTERIES

1800 Voltaic pile: silver zinc 1836 Daniell cell 1899 Junger: nickel cadmium cell 1946 Neumann: sealed NiCd 1960s Alkaline, rechargeable NiCd 1970s Lithium, sealed lead acid 1990 Nickel metal hydride (NiMH) 1991 Lithium ion 1992 Rechargeable alkaline 1999 Lithium ion polymer

TYPES OF BATTERY 

There are really only two types: Disposable (Primary Cell)

For e.g :-Zinc-chloride batteries Alkaline batteries Button cells

Lithium-ion batteries

Rechargeable (Secondary cell) For e.g:-Accumulators

PARTS OF BATTERIES

A cell has four main parts:

ELECTROLYTE

ANODE

CATHODE 

SEPARATOR

TERMS RELATING TO BATTERIES

Oxidation:- Loss of Electrons is Oxidation 

Reduction:- Gain of Electrons is Reduction

Anode:- where oxidation takes place.

Cathode:- where reduction takes place

Voltage:- is the electrical energy that it gives off, measured in volts (V)

Current:- is the rate at which electrons pass through the cell, measured in amperes (A)

WORKING OF BATTERIES

Nickel-Cadmium Battery

Cathode NiO(OH) 

Anode Cd

Separator  NaOH

WORKING OF BATTERIES

Nickel-Cadmium battery:- the reactions look something like this: 

Oxidation:- Cd(s) + 2 OH- (aq) → Cd(OH)2(s) + 2 e-

Reduction:- 2NiO(OH)(s) + 2 H2O(l) + 2 e- → 2Ni(OH)2(s) + 2 OH-

(aq) Net:-

Cd(s) + 2NiO(OH)(s) + 2 H2O(l) → Cd(OH)2(s) + 2Ni(OH)2(s)

Electrons moving from one place to another – this is electricity

Numbers of electrons in oxidation and reduction must be same.

Contd…

Alkaline Battery They all have the same voltage, because

they’re all based on the same electrochemical cell

Contd…

Reactions in Alkaline Batteries:

Oxidation Zn(s) + 2 OH- (aq) → Zn(OH)2(s) + 2 e-

Reduction 2 MnO2(s) + H2O(l) + 2 e- → Mn2O3(s) + 2

OH- (aq)

Net Zn(s) + 2 MnO2(s) + H2O(l) → Zn(OH)2(s) +

Mn2O3(s)

BATTERIES ARRANGMENTS

Serial arrangements :- In serial arrangements voltages add up

Parallel arrangements:- In parallel arrangements currents add up.

WHY RECHARGEBLE BATTERIES?

Purchasing rechargeable batteries saves money.

Protects the environment

They can be reused many times ,reducing operating cost.

WHEN NOT TO USE RECHARGEBLE BATTERY? 

They lose up to 1% of their power capacity per day.

Emergency equipment (flashlights, radios, emergency medical devices, etc…).

Low-power-use devices in difficult-to-access areas (field monitoring devices).

HOW IT IS RECHARGED? 

Recharge process is the reverse of the discharge process.

An external source of direct electrical current supplies electrons to the anode and removes them from cathode, forcing the chemical reactions into reverse

REASONS OF BATTERY DEGRADATION

Battery is connected to a device

Battery is charged  

Battery is opened  

Battery is chemically activated

World of batteries

Types of batteries:-Nickel oxyhydroxide batteryLemon batteryMolten salt batteryLead-acid batteryLithium-sulfur batteryLithium-titanate batteryNickel hydrogen batteryNickel-iron batteryNickel-zinc batteryOrganic radical battery

Zinc matrix batteryBiobatteryFlow batteriesThin film rechargeable lithium batterySilver-oxide batteryWater-activated batteryPolysulfide bromide batteryPolysulfide bromide battery

NEED FOR BATTERY EXPLORING

IN EXCESS OF SEVEN MILLION BARRELS OF GASOLINE ARE CONSUMED BY VEHICLES IN THE UNITED STATES EVERY DAY. AS SCIENTISTS RACE TO FIND ENVIRONMENTALLY SOUND SOLUTIONS TO FUEL THE WORLD'S EVER-GROWING TRANSPORTATION NEEDS, BATTERY RESEARCHERS ARE EXPLORING THE PROMISE OF LITHIUM-AIR BATTERY TECHNOLOGY.

The graph showing energy saved by each battery

Simple diagram showing mechanism in li-air battery

Mechanism in li-air battery

Li-air batteries use a catalytic air cathode that supplies oxygen, an electrolyte and a lithium anode. The technology has the potential to store almost as much energy as a tank of gasoline, and will have a capacity for energy storage that is five to 10 times greater than that of Li-ion batteries, a bridge technology. That potential, however, will not be realized until critical scientific challenges have been solved.

DISCHARGE CAPACITY OF LI-AIR BATTERY

TO 0 .1A / G DISCHARGE RATE OF DISCHARGE, THE DISCHARGE CAPACITY IS ABOUT 9000MAH / G. THE PREVIOUS LITHIUM - AIR BATTERY DISCHARGE CAPACITY OF ONLY 700 ~ 3000MAH / G, CAN BE SAID TO ACHIEVE A SUBSTANTIAL INCREASE.THE BETTER THAN LI - ION BATTERIES(THINKPAD T60 BATTERY)

Focus on the reactions in li-air battery

The project is confused on understanding more about how the chemical reaction of the battery works and investigating how to improve it. The research team is also working towards making a STAIR cell prototype suited, in the first instance, for small applications, such as mobile phones or MP3 players.

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