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Batteries And Their Importance- Essay, Research Paper
Batteries and Their ImportanceWe 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.