1 {scene: northern Italy, around 1800}
1 Como, Italy:
1 Alessandro Volta: Behold, my new invention!
1 Assistant: What is it, Professore Volta?
2 Alessandro Volta: A pile of zinc and copper plates, separated by paper soaked in acid!
3 Alessandro Volta: Now, to finish off, can you hand me that flask of sodium chloride solution?
4 Assistant: You want to combine this contraption with a salt? You'll be arrested for sure!

Alessandro Volta was a physicist who lived in the city of Como in northern Italy, from 1745 to 1827. He is most well known for his invention of the voltaic pile, which was pretty much as described in the above comic. This device produced electric current through the chemical action producing electrochemical potential between the different metals.

Technically, each individual unit of the pile, consisting of a sheet of zinc and a sheet of copper separated by wet paper is called an electrochemical cell, or just a cell if the context is clear. If you have a whole bunch of them strung together, as they were in Volta's pile, then the collection is called a battery. The name originally came from the more common term for a collection of artillery pieces: a battery of artillery. Since then, artillery has become less common in everyday life, and electric batteries much more common, so most people now think of batteries primarily as electrical devices.

The other possibility of an electrolyte (the wetting material soaking the layers of paper) between the metals, besides the acid mentioned in the comic, is simply salty water. Sodium chloride is common table salt. The important thing about the electrolyte is that it can conduct electricity, so it helps to have a salt of some sort dissolved in the water to provide electrically charged ions. (An acid can be regarded as simply a salt of hydrogen.)

Anyway, Professore Volta is another of the Scientific Revolution luminaries we're going to see occasionally in this comic theme.