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7 juillet 2010 3 07 /07 /juillet /2010 14:43

One of the most remarkable and novel 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. But the practical use of electricity has only been at our disposal since the mid-to late 1800s, and in a limited way at first. At the world exposition in Paris in 1900, for example, one of the main attractions was an electrically lit bridge over the river Seine     (Sony Vaio VGN-FZ battery).

The earliest method of generating electricity occurred by creating a static charge. In 1660, Otto von Guericke constructed the first electrical machine that consisted of a large sulphur globe which, when rubbed and turned, attracted feathers and small pieces of paper. Guericke was able to prove that the sparks generated were truly electrical     (Sony VGP-BPS8 battery).

The first suggested use of static electricity was the so-called “electric pistol”. Invented by Alessandro Volta (1745-1827), an electrical wire was placed in a jar filled with methane gas. By sending an electrical spark through the wire, the jar would explode     (SONY VGP-BPS8 battery)   .

Volta then thought of using this invention to provide long distance communications, albeit only addressing one Boolean bit. An iron wire supported by wooden poles was to be strung from Como to Milan, 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 detonate the electric pistol to signal a coded event. This communications link was never built        (Sony Vaio VGN-FZ battery)   .

Figure 1: Alessandro Volta, inventor of the electric battery    .

Volta’s discovery of the decomposition of water by an electrical current laid the foundation of electrochemistry. © Cadex Electronics Inc      (SONY VGP-BPS8 battery) .

In 1791, while working at Bologna University, Luigi Galvani discovered that the muscle of a frog contracted when touched by a metallic object. This phenomenon became known as animal electricity — a misnomer, as the theory was later disproven. Prompted by these experiments, Volta initiated a series of experiments using zinc, lead, tin or iron as positive plates. Copper, silver, gold or graphite were used as negative plates         (Sony Vaio VGN-FZ battery)       .

The next stage of generating electricity was through electrolysis. Volta discovered in 1800 that a continuous flow of electrical force was generated when using certain fluids as conductors to promote a chemical reaction between the metals or electrodes. This led to the invention of the first voltaic cell, better know as the battery. Volta discovered further that the voltage would increase when voltaic cells were stacked on top of each other          (Sony VGP-BPL9 battery)     .

In the same year, Volta released his discovery of a continuous source of electricity to the Royal Society of London. No longer were experiments limited to a brief display of sparks that lasted a fraction of a second. A seemingly endless stream of electric current was now available        (Sony VGP-BPL11 battery)           .

France was one of the first nations to officially recognize Volta’s discoveries. At the time, 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 at which Napoleon Bonaparte was present as a member of the Institute         (Sony VGP-BPL15 battery)      .

Volta’s discoveries so impressed the world that in November 1800, he was invited by the French National Institute to lectures in which Napoleon Bonaparte participated. Later, 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. © Cadex Electronics Inc        (SONY VAIO VGN-FZ4000 Battery)    .

New discoveries were made when Sir Humphry Davy, inventor of the miner’s safety lamp, 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. As reported by witnesses, his voltaic arc lamp produced “the most brilliant ascending arch of light ever seen      (Toshiba PA3399U-2BAS Battery)    .”

Davy's most important investigations were devoted to electrochemistry. Following Galvani's experiments and the discovery of the voltaic cell, interest in galvanic electricity had become widespread. Davy began to test the chemical effects of electricity in 1800. He soon found that by passing electrical current through some substances, these substances decomposed, a process later called electrolysis. The generated voltage was directly related to the reactivity of the electrolyte with the metal. Evidently, Davy understood that the actions of electrolysis and the voltaic cell were the same         (Sony VGN-FZ460E battery)        .

In 1802, Dr. William Cruickshank designed the first electric battery capable of mass production. Cruickshank had arranged square sheets of copper, which he soldered at their ends, together 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 then filled with an electrolyte of brine, or watered down acid         (Dell Inspiron E1505 Battery)      .

William Cruickshank, an English chemist, built a battery of electric cells by joining zinc and copper plates in a wooden box filled with electrolyte. This flooded design had the advantage of not drying out with use and provided more energy than Volta’s disc arrangement. © Cadex Electronics Inc           (HP PAVILION DV9700t Battery)         .

The third method of generating electricity was discovered relatively late — electricity through magnetism. In 1820, André-Marie Ampère (1775-1836) had noticed that wires carrying an electric current were at times attracted to one another, while at other times they were repelled         (IBM ThinkPad T40 Battery)       .

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, assisting Davy and his research team, succeeded in generating an endless electrical force as long as the movement between a coil and magnet continued      (Apple A1281 battery)   .

The electric generator was invented. This process was then reversed and the electric motor was discovered. Shortly thereafter, transformers were developed that could convert electricity to a desired voltage. In 1833, Faraday established the foundation of electrochemistry with Faraday's Law, which describes the amount of reduction that occurs in an electrolytic cell       (Apple M9848LL/A battery)       .

In 1836, John F. Daniell, an English chemist, continued with the research of the electro-chemical battery and developed an improved cell that produced a steadier current than Volta's device. Until then, all batteries had been composed of primary cells, meaning that they could not be recharged. In 1859, the French physician Gaston Platé invented the first rechargeable battery. This secondary battery was based on lead acid chemistry, a system that is still used today       (Dell Inspiron 6000 battery )         .

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      (Dell Inspiron E1505 battery).      .

In 1899, Waldmar Jungner from Sweden invented the nickel-cadmium battery, which used nickel for the positive electrode and cadmium for the negative. Two years later, Edison produced an alternative design by replacing cadmium with iron. Due to high material costs compared to dry cells or lead acid storage batteries, the practical applications of the nickel-cadmium and nickel-iron batteries were limited     (Dell Latitude D620 battery)    .

Toward the end of the 1800s, giant generators and transformers were built. Transmission lines were installed and electricity was made available to humanity to produce light, heat and movement. In the early twentieth century, the invention of the vacuum tube enabled generating controlled signals, amplifications and sound. Soon thereafter, radio was invented, which made wireless communication possible       (HP Pavilion dv9000 battery)      .

It was not until Shlecht and Ackermann invented the sintered pole plate in 1932 when profound improvements were achieved. These advancements were reflected in higher load currents and improved longevity. The sealed nickel-cadmium battery, as we know it toady, became only available when Neumann succeeded in completely sealing the cell in 1947         (IBM ThinkPad T41 battery)        .


From the early days on, humanity became dependent on electricity, a product without which our technological advancements would not have been possible. With the increased need for mobility, people moved to portable power storage — first for wheeled applications, then for portable and finally wearable use. As awkward and unreliable as 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        (Toshiba PA3399U-2BRS battery) .

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