Voltaic pile (Glossary)

Up until the year 1800, electricity could only be usefully generated with electrostatic machines and stored and transported to a certain extent with a Leyden jar - an early Capacitor. At that time people were still playing around with the various electrical phenomena without actually understanding the actual principle behind lightning discharges, amber sparks, the effects of an electrostatic machine or the reactions of nerves to electric currents.

We owe the first comprehensive understanding of electricity to the Italian Physicist and Professor Allesandro Volta (1745 - 1827) who taught in Como and Padua. The unit of electrical voltage was named after him 70 years after his death, the volt. Apart from several trend-setting inventions and discoveries in electrical engineering, we also have to thank him for the Voltaic pile, the first Battery in our sense whose technology has been constantly refined since those times, but whose principle has remained unchanged.

Volta's pile consisted of zinc-copper cell switched in series with a saline solution or lye as the electrolyte that was bound in saturated felt disks between the metal plates. The construction was mounted on glass rods set into wood. There were various designs for this pile.

With a basic electrolyte and the admission of air, this variant could have theoretically generated a terminal voltage of up to 1.14 volts per cell:

Over the following years, Volta discovered the contact series and improved his battery by using tin, then brass or silver as a material for the electrodes. He finally achieved the best results with the metal pairs silver-zinc and copper-zinc

Even Volta noticed in his invention that the energy flow could be reversed, in other words the pile could be recharged by supplying current. The term secondary current was coined in this context. Thus, strictly speaking Volta had not only invented the electric Cell but also the Battery (several interconnected electric cells) and the Accumulator (rechargeable battery) with his pile.

© Marc Stenzel

	See also:
		Glossary overview 'Baghdad battery' (Glossary) Historical development of the battery

[Home] [Legal] [Privacy] [GTCB] [Contact] [Search] [Siteview]