Batteries And Their Importance- Essay, Research Paper

Batteries and Their Importance-

We use batteries everyday, we use them to start our cars and

to listen to our Walkmans. I have a few questions: How do batteries

work? What are the different kinds of batteries? Why do they die? Why

do they lose energy when they are not used for a long time? Well I

tried my best to find the best answers for these questions and a

little more.

Battery, also called an electric cell, is a device that

converts chemical energy into electricity. All batteries contain an

electrolyte, a positive electrode, and a negative electrode. There are

two general types of batteries. Batteries in which chemicals cannot be

reconstituted into their original form once their energy have been

converted these are called primary cells. Batteries in which the

chemicals can be reconstituted by passing an electric current through

them in the opposite direction are known as secondary cells, are

rechargeable cells.

The primary battery is the most common type of battery used

today, invented by the French chemist Geoges Leclanche in the late

1860 s. At the time this invention was very important and helped the

start of the industrial revolution. It allowed people with portable

electricity. This popular invention was called the dry cell or

flashlight battery. The Lechlanche cell is very similar to the dry

cell we use today. The positive pole is a rode of carbon embedded in a

black manganese dioxide (MnO2) and Carbon particles and the negative

electrode is made of zinc. The electrolyte consists of a mixture of

ammonium chloride and zinc chloride made into a paste. This sits in

between the negative and positive electrodes, which acts as an ionic

conductor. When the cell is in use, atoms of the Zinc in the outer

case are oxidized, giving up electrons and forming zinc ions.

Zn – 2e Zn++

The electrons are lost by the zinc atoms then flow through the load

(the device being powered) and supply energy. They re-enter the cell

at the carbon rode that serves as the positive electrode. As this

series of events happen, the battery begins to lose pure zinc atoms,

and the battery starts to die. This type of cell gives about 1.5 volts

of energy. By connecting many cells in a series a rather high voltage

can be produced.

Another type of primary cell is the mercury cell. This cell

uses zinc as the negative electrode, mercury as the positive

electrode, and potassium hydroxide as the electrolyte. This cell gives

about 1.3 volts of electricity, and is used in hearing aids and

watches because the battery can be flattened.

Primary cells maintain a positive charge on the positive

terminal and a negative charge on the negative terminal, month after

month. These charges attract another and sometimes manage to get to

each other through the battery it self. When this happens the battery

loses some energy. This is why batteries lose energy if not used. It

is possible to slow this process down by refrigerating batteries.

Dry Cell Battery

The storage, or secondary cell, which can be recharged by

reversing the chemical reaction, was invented in 1859 by the French

physicist Gaston Plante. This invention was very crucial because it

would revolutionize cars. Instead of crank starts the lead-acid

battery was used. The lead-acid, which Plante invented is still the

same basic design today. The battery consists of six cells connected

in a series, and is used in automobiles. Its chief advantage is that

it can deliver a strong current of electricity (starting an engine),

however it runs down quickly. Each cell is made up of a number of

positive and negative plates, separated by thin layers of wood, hard

rubber, or plastic, called separators. All the positive plates are

connected to one strap, and all the negative plates are also connected

to one strap. The straps are connected to terminal posts, positive and

negative. Each of the plates are in the form of grids containing

pockets. The positive plates pockets are filled with a paste of lead

dioxide (PbO2). The negative plates are filled with spongy lead (Pb).

Both plates are immersed in a solution of sulfuric acid, this acts as

the electrolyte. When the battery is in use, the lead atoms in the

negative plates lose electrons and become lead ions (Pb++). These ions

combine with the electrolyte to form a white coating of lead sulfate

on the negative plate.

Pb++ + SO4- PbSO4

When the electrons make through the load and arrive on the positive

pole they form a white coating of lead sulfate on the positive plate

also. The coat of lead sulfate makes the battery less efficient. When

an outside current is applied the reaction happens backwards, changing

the lead sulfate coating on each plate to lead and lead dioxide. After

this the battery is recharged.

Lead-acid storage

Another widely used secondary cell is the alkaline cell, which

was invented by the American, Thomas Edison in the 1900 s. It works

similar to the lead-acid battery, but it is much smaller. A

disadvantage is that the battery loses a little bit of capacity each

time it is charged.

In recent years a number of new types of batteries have been

designed for use in electric vehicles and other applications. In

improving various conventional storage batteries, they have been able

to make electric cars and longer lasting batteries. Still there exits

some draw backs to these batteries, either short range, high expense,

bulkiness, or environmental problems. The U.S Advanced Battery

Consortion (USADC) was set up in 1991 to speed up development of new

storage batteries. Batteries are being developed that cause no

environmental hazards and occupy little space. All this advancement in

batteries is wonderful, but we need to see the importance batteries

play in the world today. The world is dependent on the battery, from

the use in cars to calculators. The battery is one of the few sources

of energy that is universal, a Japanese calculator can still work with

batteries found in the U.S no electric conversion is needed. This is

reason why the battery is so needed and important to the world.