Batteries battery pile

Fig. 27. Cross-section of SNDC iron—air battery pile (93).

Luigi Galvani (1791) was the first to discover the physiological action of electricity. He demonstrated the existence of bioelectric forces in animal tissue. His experiments led Alessandro Volta to the invention of the first battery, voltaic pile [8]. In 1800, Alessandro Volta described the voltaic pile in a letter to the Royal Society in London [7]. The original voltaic cell used two metal disks as electrodes, namely zinc and silver. Cardboard disks separated the electrodes and seawater was the electrolyte. A current was produced when the silver disk was connected to the zinc disk through an external wire. The voltaic pile established the foundation for the liquid battery type. Many other metals and electrolytes have been tried during the last two centuries [9]. 

Alessandro Volta, Italian physicist, discovered why the frog s leg twitched. He built the first battery (voltaic pile) of stacked Ag-Zn plates separated by paper or cloth soaked in saltwater. 

A battery cell that became popular during the nineteenth century was constructed in 1836 by the English chemist John Frederick Daniell.This cell used zinc and copper. The basic principle was that of Volta s battery pile, but each metal was surrounded by a solution of the metal ion, and the solutions were kept separate by a porous ceramic barrier. Each metal with its solution was a half-cell a zinc half-cell and a copper half-cell made up one voltaic cell.This construction became the standard form of such cells, which exploit the spontaneous chemical reaction... 

Intercetl Connections. In a series-arranged battery of pile constraction, the anode of one cell is connected to the cathode of the adjacent cell. To accomplish this without producing a short-circuited cell, an insulating tape or film is placed between the electrodes on nonsilver batteries. For silver batteries silver foil is used alone or in conjunction with an insulating tape. 

FIGURE 25.17 Cross section of Swedish National Development Corporation s iron/air battery pile. From Ref. 5.)... 

Cell geometry, such as tab/terminal positioning and battery configuration, strongly influence primary current distribution. The monopolar constmction is most common. Several electrodes of the same polarity may be connected in parallel to increase capacity. The current production concentrates near the tab connections unless special care is exercised in designing the current collector. Bipolar constmction, wherein the terminal or collector of one cell serves as the anode and cathode of the next cell in pile formation, leads to gready improved uniformity of current distribution. Several representations are available to calculate the current distribution across the geometric electrode surface (46—50). 

Metallic zinc was used as a material for the negative electrode in the earliest electrical cell, Volta s pile, and is still employed in a variety of batteries, including batteries with alkaline electrolytes. 

During the next decades after the appearance of the Volta pile and of different other versions of batteries, fundamental laws of electrodynamics and electromagnetism were formulated based on experiments carried out with electric current supplied by batteries Ampere s law of interaction between electrical currents (1820), Ohm s law of proportionality between current and voltage (1827), the laws of electromagnetic induction (Faraday, 1831), Joule s law of the thermal effect of electric current, and many others. 

Uses. Large quantities of Sb metal have been used mainly in alloys with Pb (battery grids) and other metals. Alloys are the predominant use of antimony because its brittleness bars direct use. High purity antimony (>99.999%) has a limited but important application in the manufacture of semiconductor devices. When alloyed with elements of 13th group (IIIA), the III-V compounds are formed these have important applications as infrared devices, diodes and Hall effect devices. Also used for fireworks and thermoelectric piles. 

Arfwedson and Gmelin tried in vain to isolate lithium metal After faffing to reduce the oxide by heating it with iron or carbon, they tried to electrolyze its salts, but their voltaic pile was not sufficiently powerful (14). W. T. Brande succeeded in decomposing Iithia with a powerful battery and obtained a white, combustible metal, and Davy also obtained a small amount of hthium in the same manner (14,15, 31, 32, 33). 

When the news of Davy s isolation of the alkali metals reached Paris in 1808, Napoleon provided Gay-Lussac and Thenard with a powerful voltaic pile. Before it could be set up, however, they showed that these metals can be obtained without a battery simply by reducing the caustic alkali with metallic iron at a high temperature, a method which... 

The first batteries date from the early 1800s. They consisted of a stack of disks made of two different metals, arranged alternately, with pads of cloth soaked in salt solution in-between each layer. A pile of nickel and copper coins separated by blotting paper that has been dipped in salty water will do just as well. Electrons will flow through the pile, from nickel to copper, but cannot escape until the top and bottom are connected by a wire. 

On several occasions the electrolysis of water has been mentioned. This was one of the first investigations conducted with Volta s pile. The electrolysis of water can be observed by placing a small 9 V battery in a glass of water and sprinkling in a little salt (to create an electrolyte to conduct current). Very soon a steady stream of bubbles will appear emerging from the positive and negative terminals. The standard half reactions representing the electrolysis of water are... 

In his original design Volta stacked couples of unlike metals one upon another in order to increase the intensity of the current. This arrangement became known as the "voltaic pile." He studied many metallic combinations and was able to arrange the metals in an "electromotive series" in which each nielal was positive when connected to the one below it in the series. Volta s pile was the precursor of modem batteries. 

His "Voltaic pile", a stack of zinc and silver disks separated by a wet cloth containing a salt or a weak acid solution, was the first battery known to Western civilization. 

Before 1800, electricity meant static electricity, generated by friction. It could be stored in jar-like condensers, and a number of these condensers could be discharged simultaneously, like an artillery battery, producing a very hefty shock—up to half a million volts. The sparks from such discharges could ignite gas mixtures and decompose relatively small samples of some substances. Then in 1800, Volta published a description of a new piece of apparatus, the electric pile. It was called a pile because it consisted literally of a pile of alternating disks of metals and blotting paper moistened with a salt solution. It was... 

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