Alessandro Volta and first Electrical Battery
Alessandro Giuseppe Antonio Anastasio Volta (18 February 1745 – 5 March 1827) was an Italian physicist and chemist who is credited as the inventor of the electrical battery and the discoverer of methane.
Alessandro Volta was one of the enthusiastic admirers of Galvani. He repeated Galvani's experiments many times with many different materials. From these experiments he came to the conclusion that it was the two dissimilar metals, not the frog’s leg that produced the electricity. The frog’s leg was just an indicator of presence of the electricity. Refer to the frog leg stimulation experiments for more details.
In 1800, after extensive experimentation, he developed the voltaic pile, an early electric battery, which produced a steady electric current. Volta had determined that the most effective pair of dissimilar metals to produce electricity was zinc and silver. Initially he experimented with individual cells in series, each cell being a wine goblet filled with brine into which the two dissimilar electrodes were dipped. The voltaic pile replaced the goblets with cardboard soaked in brine
The battery made by Volta is credited as the first electrochemical cell. It consists of two electrodes: one made of zinc, the other of copper. The electrolyte is either sulphuric acid mixed with water or a form of saltwater brine. The electrolyte exists in the form 2H+ and SO42−. The zinc, which is higher in the electrochemical series than both copper and hydrogen, reacts with the negatively charged sulphate (SO42−). The positively charged hydrogen ions (protons) capture electrons from the copper, forming bubbles of hydrogen gas, H2. 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 reactions in this voltaic cell are as follows:
Zinc: Zn → Zn2+ + 2e−
Sulphuric acid: 2H+ + 2e− → H2
The copper does not react, but rather it functions as an electrode for the electric current.
Although this cell is a great proof of concept and represents a giant step towards opening up a new field, it is not the most optimized battery in terms of performance. Apart from the fact that it was a primary battery, it was also unsafe to handle, since sulphuric acid, even if diluted, can be hazardous. Also, the power of the cell diminishes over time because the hydrogen gas is not released.
The SI unit of electric potential is named in his honour as the volt. For his achievements he has also found a place on the currency of United States along with a picture of his first optimized battery.