Alessandro Volta

Volta soaked some paper in salt water and put it between a piece of silver and a piece of zinc, like a sandwich. Then he connected the two metals with a piece of wire. He found that electricity was passing through the wire. However, it was a very weak current.

So, Volta made a pile of "sandwiches" and when he connected them all together, the electricity was strong enough to cause sparks.

Today's batteries work in a similar way to the Voltaic pile, as it was called. A carbon rod reacts with a chemical paste inside the cell, which reacts with the zinc casing, to send electricity to the positive and negative terminals of the battery.