In the modern era, electrical energy is normally converted from mechanical energy, solar energy, and chemical energy etc. A battery is ...
In the modern era, electrical energy is normally converted from mechanical energy, solar energy, and chemical energy etc. A battery is a device that converts chemical energy to electrical energy. The first battery was developed by Alessandro Volta in the year of 1800. In the year 1836, John Frederic Daniell, a British chemist developed the Daniell cell as an improved version of the voltaic cell. From that time until today, the battery has been the most popular source of electricity in many daily life applications.In our daily life, we generally use two types of battery, one of them is which can be used once before it gets totally discharged. Another type of battery is rechargeable which means it can be used multiple times by recharging it externally. The former is called primary battery and the later is called secondary battery.
Batteries can be found in different sizes. A battery may be as small as a shirt button or may be so big in size that a whole room will be required to install a battery bank. With this variation of sizes, the battery is used anywhere from small wrist watches to a large ship.

History of Battery

In the year of 1936 during the middle of summer, an ancient tomb was discovered during construction of a new railway line near Bagdad city in Iraq. The relics found in that tomb were about 2000 years old. Among these relics, there were some clay jars or vessels which were sealed at the top with pitch. An iron rod, surrounded by a cylindrical tube made of wrapped copper sheet was projected out from this sealed top.
When these pots were filled with an acidic liquid, they produced a potential difference of around 2 volts between the iron and copper. These clay jars are suspected to be 2000 year old battery cells.




Step by Step Development in History of Batteries
Developer/Inventor | Country | Year | Invention |
Luigi Galvani | Italy | 1786 | Animal Electricity |
Alessandro Volta | Italy | 1800 | Voltaic Pile |
John F. Daniell | Britain | 1836 | Daniell Cell |
Sir William Robert Grove | Britain | 1839 | Fuel Cell |
Robert Bunsen | German | 1842 | used liquid electrodes to supply electricity |
Gaston Plante | France | 1859 | Lead Acid Battery |
Georges Leclanche | France | 1866 | Leclanche Cell |
Thomas Alva Edison | United States | 1901 | Alkaline Accumulator |
Working Principle of Battery
To understand the basic principle of battery properly, first, we should have some basic concept of electrolytes and electrons affinity. Actually, when two dissimilar metals or metallic compounds are immersed in an electrolyte, there will be a potential difference produced between these metals or metallic compounds.
It is found that, when some specific compounds are added to water, they get dissolved and produce negative and positive ions. This type of compound is called an electrolyte. The popular examples of electrolytes are almost all kinds of salts, acids, and bases etc.
The energy released during accepting an electron by a neutral atom is known as electron affinity. As the atomic structure for different materials are different, the electron affinity of different materials will differ. If two different kinds of metals or metallic compounds are immersed in the same electrolyte solution, one of them will gain electrons and the other will release electrons. Which metal (or metallic compound) will gain electrons and which will lose them depends upon the electron affinities of these metals or metallic compounds. The metal with low electron affinity will gain electrons from the negative ions of the electrolyte solution. On the other hand, the metal with high electron affinity will release electrons and these electrons come out into the electrolyte solution and are added to the positive ions of the solution. In this way, one of these metals or compounds gains electrons and another one loses electrons. As a result, there will be a difference in electron concentration between these two metals. This difference of electron concentration causes an electrical potential difference to develop between the metals. This electrical potential difference or emf can be utilized as a source of voltage in any electronics or electrical circuit. This is a general and basic principle of battery .
Zinc in diluted sulfuric acid gives up electrons as below:


These Zn + + ions pass into the electrolyte, and their concentration is very high near the zinc electrode. As a result of the above oxidation reaction, the zinc electrode is left negatively charged and hence acts as cathode. The diluted sulfuric acid and water disassociate into hydronium ions as given below:


Due to the high concentration of Zn + + ions near the cathode, the H3O+ ions are repelled towards the copper electrode and get discharged by removing electrons from the copper atoms. The following reaction takes place at the anode:


As a result of the reduction reaction taking place at copper electrode, copper is left positively charged and hence it acts as the anode.
Daniell Battery Cell: The Daniell cell consists of a copper vessel containing copper sulfate solution. The copper vessel itself acts as the positive electrode. A porous pot containing diluted sulfuric acid is placed in the copper vessel. An amalgamated zinc rod dipping inside the sulfuric acid acts as the negative electrode.
When the circuit is completed, diluted sulfuric acid in the porous pot reacts with zinc so as to liberate hydrogen gas. The reaction takes place as below:


The formation of ZnSO4 in the porous pot does not affect the working of the cell, until crystals of ZnSO4 are deposited.
The hydrogen gas passes through the porous pot and reacts with the CuSO4 solution as below:


Copper so formed gets deposited on the copper vessel.
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