“What is the simplest possible battery?”
Batteries are some of the most omnipresent electrical components in human civilization. However, what is the most simple form of them? Well, in order to do that, we have to put everything into it’s most basic parts.
Well, let’s suppose we have a slab of zinc and a slab of copper, both occupying space in separate dishes of water. Both of them have some of their substance dissolved in the water. The electrons on the zinc solvent want to leave the element, while the copper solvent (with a charge of +2) wants to obtain electrons. If we connect both the copper and the zinc slab with a conducting wire, then the extra electrons on the zinc side will sense the voltage potential on the other side, creating a current, with the zinc side being the cathode and the copper side being the anode. The zinc increasingly becomes oxidized, while the copper becomes increasingly redoxed. However, as this process progresses, more zinc cations will be generated along with the disappearance of more anions, leading to a short life time!. To solve this problem, a salt bridge is instituted connecting the zinc and lead sides. This salt bridge is made up of Potassium Chloride [KCl] in a pseudo-aqueous solution (meaning that it is viscous to a point that the salt will not immediately react with the surrounding elements). As the process goes on and both sides become more charge neutral, the salt will break up bit by bit to have the positive potassium ions replenish the charge of the copper and the negative chloride will replenish the charge of the zinc
This in turn creates a simple battery, called a galvanic cell (Also termed a voltaic cell, after the Two Italian scientists Luigi Galvani and Alessandro Volta, respectively).