the chemistry inside the battery

In chemistry and electrochemistry, any device which converts chemical energy into electric energy is termed a battery. The battery is normally a group of two or more galvanic cells capable of converting energy, and generally, it is applied to a single cell.

The battery is also known as a cell which consists of a cathode or a positive plate. Similarly, on the other hand, it consists of an anode or a negative plate. These electrodes are separated and usually absorbed in an electrolyte that allows the passage of ions between those electrodes. These materials of electrodes and electrolytes are selected and arranged in such a manner so that enough electromotive force and current can easily develop between the battery terminals. The electric current that occurred from this process is later used to operate lights, electric machines, and other devices that need a current power supply to run.

Types of battery

The batteries are commonly divided into two categories, that are:

• Primary battery (primary cell)
•   Secondary battery (secondary cell)

Primary battery

A primary battery is also known as a primary cell. In primary batteries, the redox reactions proceed in only one single direction. After a certain period of time, the primary battery’s reactants are consumed, usually surrendering as dead. If the chemical inside the primary battery is exhausted, it cannot be used further for any purpose.

The dry cell is a good example of a primary battery. Household batteries are commonly used to power small things like TV remotes, clocks, small machines. Zinc works as the anode, and carbon rods act as a cathode in primary cells. A kind of manganese dioxide mixture in powder form is placed around the cathode. The given space between the container and the rod is filled with ammonium chloride and zinc chloride.

Following is the reaction that takes place in these primary cells:

At Anode

Zn(s) –> Zn2+ (aq) + 2e–

At Cathode

2e– + 2 NH4+ (aq) –> 2 NH3 (g) + H2 (g)

2 NH3 (g) +Zn2+ (aq) –> [Zn (NH3)2] 2+ (aq)

H2 (g) + 2 MnO2 (S) –> Mn2O3 (S) + H2O (l)

Hence, the whole equation of this primary cell will be like this:

Zn(s) + 2 NH4+ (aq) + 2 MnO2 (S) –> [Zn(NH3)2] 2+ (aq) + Mn2O3 (S) + H2O (l)

Mercury cells are another good example of primary batteries or cells as zinc. Mercury amalgam is purposely used as an anode and carbon as a cathode. Therefore, the mixture paste of HgO is further used as an electrolyte. A device that needs a comparatively low supply of electric current, primary cells are used like hearing machines, TV remotes, watches, clocks.

Secondary battery

The secondary battery is also known as the secondary cell. It can be used again after bypassing current through the electrodes present in the opposite direction, which means from the negative terminal to the positive terminal.

 For example, in automobiles, the lead storage battery is generally used, and we can charge the inverter again, but there is also a limit. One cannot charge it unlimited times. The cathode is a lead grid that is packed with lead oxide, and the storage of the lead battery has a lead anode. It is used as an electrolyte when there is a 38% concentration in sulphuric acid.

The reaction of reduction and oxidation involved in this process are given below.

At Anode

Pb –> Pb2++ 2 e–

Pb+ SO42– –>PbSO4(electrode) + 2 e–

At Cathode

2 e–+ PbO2+ 4 H+ –> Pb2++ 2 H2O

2 e–+ PbO2+ 4 H++ SO42- –> PbSO4(electrode) + 2 H2O

To recharge these batteries or cells , the amount of charge which is transferred is transferred back in reverse direction and the converting PbSO4 back to Pb and PbO2.

Nickel-cadmium cell is another good example of a secondary cell. The lifespan is relatively long and these cells have a high capacity of storage as compared to other secondary cells. However, it is very difficult to manufacture and maintain them.

Working of battery is always based on application, so further they are classified as:

Household batteries

Household batteries are known as the common man as they are commonly used in home appliances like clocks, torches, remote, camera, small machines. These household batteries are again classified into two subcategories:

• The first example is rechargeable batteries of nickel which includes Cadmium batteries and lithium-Ion.
• Another is Non- rechargeable batteries. Some of the examples are alkaline, carbon-zinc, and silver oxide.

Industrial Batteries

All the heavy-duty requirements are done under the industrial batteries because industries’ workload is heavy and has to be done in industrial batteries. The amount of electric current required is too heavy and powerful. Some of their applications are railroad, backup of power, and another such big requirement in companies.

Some of the examples of such batteries are Nickel Iron and Wet Nickel Cadmium.

Vehicle Batteries

Comparing it with industrial batteries, these are easier to use and considered to be less complicated. Unlike industrial batteries, all motorcycles, boats, and other vehicles have these vehicle batteries because they need less force to run.

The lead-acid battery is the most important example of vehicle batteries.

Conclusion

The battery is also known as a cell which consists of a cathode, or a positive plate, similarly on the other hand; it consists of an anode or a negative plate. A primary battery is also known as a primary cell. In primary batteries, the redox reactions proceed in only one single direction.

After a given period of time, the reactants of the primary batteries are being consumed, then surrendered as dead. The secondary battery is also known as the secondary cell. It can be used again after bypassing current through the electrodes present in the opposite direction, which means from the negative terminal to the positive terminal.