Battery

 

Batteries, we use them for almost everything. Most of us don’t know how batteries work, the different types of batteries, so on. So let me just start by showing how batteries are really made.

The battery was first found way back in the days. It was even before Christ was born. It was in the 250’s B.C. The batteries were not much used those days. So the batteries came into use when Alessandro Volta rediscovered it. He was born in 1745 and died in 1827. Now days the batteries have gone through some changes, like the size of the battery, the weight and the components. A french engineer, Georges Leclanche, made a battery that is widely used now days, it is the zinc carbon cell battery. Carl Gassner of Mainz was the one who created the dry cell battery.

The batteries have a positive part that is called a cathode and a negative part that is called an anode. There is a mixture of manganese dioxide, graphite and an electrolyte and this mixture is inserted into a cylinder called the preforms. Then the preform is put in a steel can. The positive part of the battery is the preforms and the steel can. Just in case the cathode does not leak there is a sealant used. The negative part is zinc powder and some other materials, in gel form. The seal for the anode is made of brass nail, a plastic seal and metal end cap. Now the anode part is inserted into the steel can. Since the cathode and the anode can’t touch each other, there is a separator. All this is showed in this picture.

Batteries work a lot. When we look at a battery all we see is just a plane battery and we think that nothing is happening, but in reality the battery does a lot. The batteries are electrochemical cells, they convert chemical energy to electrical energy using 3 things; the anode, the cathode, and the electrolyte. The anode is a metal, the cathode is a metallic oxide and the electrolyte is an electricity conductor. When you turn the switch on of a flashlight, the battery sends electric current in the form of electrons. That is when the anode gives away 2 of its zinc electrons per atom and this is called the oxidation. Oxidation leaves out the unstable zinc ions. On the picture below the electrons are illustrated as a "e", the zinc is illustrated as "ZN" and the zinc ions are illustrated as "ZN2+".

Now the light bulb is lit. The light bulb re-enters the battery at the cathode. There the cathode gets combined with manganese dioxide. This is called the reduction. In the picture below the manganese dioxide is illustrated as "MnO2".

The electrolyte is the one that carries the electrons back to the anode, when it goes into the cathode. When an electron enters the cathode, it reacts with the manganese dioxide to form MnOO-. Then the MnOO- reacts with water in the electrolyte solution. The water releases hydroxide ions (OH-) and hydrogen ions (H+), which combine with MnOO- to form MnOOH. Then the hydroxide ions go to the anode in the form of an ionic current. There, they combine with the unstable zinc ions, which had given up their electrons to power the lightbulb. The reaction produces zinc oxide (ZnO) and water (H2O).

Now the different types of batteries. There are many different kinds of batteries but the most often used batteries are the alkaline batteries, the dry-cell batteries and the rechargeable batteries. So let me inform you about the difference between these 3 types of batteries. Well the difference between a rechargeable battery and an alkaline battery is that the rechargeable battery has a reversible chemical reaction, and the alkaline battery does not. The chemical reaction of a rechargeable battery is NiO reacts with CdO to form NiO2 and Cd, this reaction can be reversed so the battery is rechargeable. The chemical reaction of an alkaline is Zn oxidizes to form ZnO. You cannot reduce ZnO to form Zn, which means that the battery is not rechargeable. The dry cell battery uses ammonium instead of zinc, which is how it differs from the alkaline battery. The dry cell battery’s chemical reaction isn’t reversible, this is how it differs from the rechargeable battery. In other words the rechargeable batteries are used several times and the normal batteries you can just use it once.

By: Piratheepan Manickavasakar