One of the most important discoveries in the last 400 years has been electricity. You may ask, "Has electricity been around that long?" The answer is "yes", and perhaps much longer. Surprisingly, electricity only became useful to humanity in the late 1800s.

The earliest known methods of generating electricity were by creating a static charge. Alessandro Volta (1745-1827) invented the so-called "electric pistol" by which an electrical wire was placed in a jar filled with methane gas. By sending an electrical spark through the wire, the jar would explode.

Volta then thought of using this invention to provide long distance communications, albeit only one Boolean bit. An iron wire supported by wooden poles was to be strung from Como to Milan in Italy. At the receiving end, the wire would terminate in a jar filled with methane gas. On command, an electrical spark is sent by wire that would cause a detonation to signal a coded event. This communications link was never built.

The next stage of generating electricity was through electrolysis. Volta discovered in 1800 that a continuous flow of electrical force was possible when using certain fluids as conductors to promote a chemical reaction between metals. Volta discovered further that the voltage would increase when voltaic cells were stacked. This led to the invention of the battery.
From the availability of a battery, experiments were no longer limited to a brief display of sparks that lasted a fraction of a second. A seemingly endless stream of electric current was now available.

In the early 1800, France was approaching the height of scientific advancements and new ideas were welcomed with open arms to support the political agenda. By invitation, Volta addressed the Institute of France in a series of lectures in which Napoleon Bonaparte was present. Napoleon himself helped with the experiments, drawing sparks from the battery, melting a steel wire, discharging an electric pistol and decomposing water into its elements.

Figure 1: Volta's experimentations at the French National Institute in November of 1800 in which Napoleon Bonaparte was present.


 

In 1802, Dr. William Cruickshank designed the first electric battery capable of mass production. Cruickshank arranged square sheets of copper soldered at their ends, intermixed with sheets of zinc of equal size. These sheets were placed into a long rectangular wooden box that was sealed with cement. Grooves in the box held the metal plates in position. The box was filled with an electrolyte of brine, or watered down acid.

New discoveries were made when Sir Humphry Davy installed the largest and most powerful electric battery in the vaults of the Royal Institution of London. He connected the battery to charcoal electrodes and produced the first electric light. Witnesses reported that his voltaic arc lamp produced "the most brilliant ascending arch of light ever seen."

All batteries at this time were primary cells, meaning that they could not be recharged. In 1859, the French physicist Gaston Plant?invented the first rechargeable battery. This secondary battery was based on lead acid, a chemistry that is still used today.

Figure 2: History of battery development.
The battery may be much older. It is believed that the Parthians who ruled Baghdad (ca. 250 BC) used batteries to electroplate silver. The Egyptians are said to have electroplated antimony onto copper over 4300 years ago.

The third, and most significant, method of generating electricity was discovered relatively late - electricity through magnetism. In 1820, Andr?Marie Ampère (1775-1836) had noticed that wires carrying an electric current were at times attracted to one another, while at other times repelled. In 1831, Michael Faraday (1791-1867) demonstrated how a copper disc was able to provide a constant flow of electricity when revolved in a strong magnetic field. Faraday and his research team succeeded in generating an endless electrical force as long as the movement between a coil and magnet continued.

In 1899, Waldmar Jungner from Sweden invented the nickel-cadmium battery. In 1947, Neumann succeeded in completely sealing the cell. These advances led to the modern sealed nickel-cadmium battery in use today.
 

Research of the nickel-metal-hydride system started in the 1970s but the metal hydride alloys were unstable in the cell environment. New hydride alloys were developed in the 1980s that improved the stability. nickel-metal-hydride became commercially available in the 1990s.

The first primary lithium batteries appeared in early 1970s. Attempts to develop rechargeable lithium batteries followed in the 1980s but failed due to safety problems. Because of inherent instability of lithium metal, especially during charging, research shifted to a non-metallic lithium battery using lithium ions. Although lower in energy density than lithium metal, lithium? ion is safe, provided certain precautions are met when charging and discharging. In 1991, the Sony Corporation commercialized the first lithium-ion battery.

As awkward and unreliable the early batteries may have been, our descendants may one day look at today's technology in a similar way to how we view our predecessors' clumsy experiments of 200 years ago.