Question

What is an AGM battery?

Answer 1

Hint: An electrochemical cell is a device that converts chemical energy into electrical energy and supplies power to electronic appliances. A combination of cells is called a battery.

Complete Step by Step Solution:
Batteries are of different types. One of them is the primary battery.
A primary cell cannot be reused again after its electrolyte is depleted. It cannot be recharged.
For example - Lead-acid batteries
AGM battery means Absorbent Glass Mat. It uses fibreglass and hence, its name. It is a developed lead-acid battery.

In the lead storage battery, each cell comprises a lead anode and a grid of lead-filled with lead dioxide (\[{\rm{Pb}}{{\rm{O}}_{\rm{2}}}\]) as a cathode. A solution of Sulfuric acid is the electrolyte.
Sulfuric acid provides the sulphate ions for the facilitation of the reaction.
Reactions happening at different electrodes are as follows:

Anode: .\[{\rm{Pb(s) + SO}}_{\rm{4}}^{{\rm{2 - }}}{\rm{(aq)}} \to {\rm{PbS}}{{\rm{O}}_{\rm{4}}}{\rm{(s) + 2}}{{\rm{e}}^{\rm{ - }}}\].

Cathode: \[Pb{O_2}\left( s \right) + SO_4^{2 - }\left( {aq} \right){\rm{ }} + {\rm{ }}4{H^ + }{\rm{ }}\left( {aq} \right){\rm{ }} + {\rm{ }}2{e^ - }{\rm{ }} \to 2PbS{O_4}\left( s \right) + 2{H_2}O\left( l \right)\]

Overall reaction: \[\begin{array}{*{20}{l}}{Pb\left( s \right){\rm{ }} + {\rm{ }}Pb{O_2}\left( s \right) + {\rm{ }}2{H_2}S{O_4}\left( {aq} \right){\rm{ }} \to 2PbS{O_4}\left( s \right){\rm{ }} + {\rm{ }}2{H_2}O{\rm{ }}\left( l \right)}\\\;\end{array}\]

On charging the battery, the reverse reaction occurs.

The lead-acid battery utilises lead plates immersed in Sulfuric acid.
The gases generated during its chemical reaction are released into the atmosphere, resulting in the loss of water. So, the easy electrolyte gets consumed easily.

In the AGM battery, a fibreglass covering is placed between lead plates. The glass mat maintains the electrolyte suspended in a position and not free-flowing.
It is a sealed battery because of which there is no loss of gases. Gases formed during the chemical reaction combined with the electrolyte.

The AGM battery is maintained easily. The glass mat procedure ensures no spilling of electrolytes. This battery due to its less internal resistance furnishes high voltage to the appliances while recharging.

 Hence, the AGM battery is an advanced version of a Lead-acid battery which requires less maintenance and provides more voltage.

Note: Due to its many advantages over Lead-acid batteries, AGM batteries are used for the high demand for voltage in automobiles, aeroplanes, and submarines, presently they are also used in ordinary cars and trucks.