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Combinations of Metals That Make Electricity






It was a pair of Italians who first used metal combinations to make electricity. Luigi Galvani noticed that preserved frog legs in his laboratory twitched in the midst of thunder and lightning storms. Working off of this observation, he found he could induce more twitching by touching frog legs with various metals. He called this phenomena " animal electricity." Alessandro Volta dispensed with the frog legs and substituted stacks of metal plates separated by cardboard soaked in brine, producing a voltage.

Copper and Zinc. Copper and zinc produce electricity when combined with the phosporic acid found in potatoes.

Through further experimentation, Volta found copper and zinc produced the strongest, most consistent voltage of the metals available to him. He further found that different combinations of metals produced better results. Pairing zinc, lead, tin or iron with copper, silver, gold or carbon produced voltages. Using the same metal does not produce a voltage because there is no potential difference between them. These metals in combination with an electrolyte such as brine or citric acid produce electricity, but they are not rechargeable and eventually stop producing electricity as the hydrogen atoms in the electrolyte get used up.

Lead-Acid. The sealed lead-acid battery found in most automobiles today goes back to French physician Gaston Plante’s 1859 design of a cell consisting of lead electrodes and sulphuric acid. This design produces electricity only after charging, when electrons are introduced into one of the lead electrodes, turning it into the cathode and converting it to lead oxide. This creates a potential between the two electrodes, producing electricity. With their high content of lead and acid, these batteries can be harmful for the environment when not disposed of properly.

Nickel-cadmium and Nickel-Iron. Edison replaced cadmium with iron, resulting in a cheaper but less efficient battery. Wlademar of Jungner of Sweden introduced the nickel-cadmium battery in 1899. Rechargeable like the lead-acid cell, this battery did not initially enjoy commercial success because of the prohibitively high costs of materials. Thomas Edison substituted iron for cadmium in 1901, producing a cheaper but less efficient cell given to self-discharge and poor performance at low temperatures. Ni-Cad became popular with the development of an improved pole piece in 1932, resulting in a longer-lasting and more efficient battery.

Lithium-Cobalt Oxide. The lithium-ion family of batteries use a variety of metals to produce electricity. Powering cell phones and laptops, the metals producing electricity in this cell consist of a cobalt oxide cathode and a graphite anode. The widespread use of these batteries creates more chances of failure: metal fragments reach the core and cause a short circuit, resulting in rapid discharge and increased heat. This heat can damage the components of the object it powers. Therefore, phone and laptop users must be vigilant when it comes to excess device heat.






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