Editing Alessandro Volta (section)

== Early battery ==
[[File:Voltaic pile.svg|thumb|A [[voltaic pile]]]]
In announcing his invention of the voltaic pile, Volta paid tribute to the influences of [[William Nicholson (chemist)|William Nicholson]], [[Tiberius Cavallo]], and [[Abraham Bennet]].<ref name="elliott" />

The battery made by Volta is credited as one of the first electrochemical cells. It consists of two electrodes: one made of [[zinc]], the other of [[copper]]. The [[electrolyte]] is either [[sulfuric acid]] mixed with water or a form of saltwater [[brine]]. The electrolyte exists in the form {{chem2|2 H+}} and {{chem2|SO4(2−)}}. Zinc metal, which is higher in the [[standard electrode potential (data page)|electrochemical series]] than both copper and hydrogen, is oxidized to zinc cations (Zn<sup>2+</sup>) and creates electrons that move to the copper electrode. The positively charged hydrogen ions ([[proton]]s) capture [[electron]]s from the copper electrode, forming bubbles of hydrogen gas, H<sub>2</sub>. This makes the zinc rod the negative electrode and the copper rod the positive electrode. Thus, there are two terminals, and an electric current will flow if they are connected. The [[chemical reaction]]s in this voltaic cell are as follows:

:Zinc:
::{{chem2|Zn → Zn(2+) + 2e-}}

:Sulfuric acid:
::{{chem2|2H+ + 2e- -> H2}}

Copper metal does not react, but rather it functions as a [[Catalysis|catalyst]] for the hydrogen-gas formation and an electrode for the electric current. The sulfate anion ({{chem2|SO4(2-)}}) does not undergo any chemical reaction either, but migrates to the zinc anode to compensate for the charge of the zinc cations formed there. However, this cell also has some disadvantages. It is unsafe to handle, since sulfuric acid, even if diluted, can be hazardous. Also, the power of the cell diminishes over time because the hydrogen gas is not released. Instead, it accumulates on the surface of the copper electrode and forms a barrier between the metal and the electrolyte solution.