Résumé
A zinc–carbon battery (or carbon zinc battery in U.S. English) is a dry cell primary battery that provides direct electric current from the electrochemical reaction between zinc (Zn) and manganese dioxide (MnO2) in the presence of an ammonium chloride (NH4Cl) electrolyte. It produces a voltage of about 1.5 volts between the zinc anode, which is typically constructed as a cylindrical container for the battery cell, and a carbon rod surrounded by a compound with a higher Standard electrode potential (positive polarity), known as the cathode, that collects the current from the manganese dioxide electrode. The name "zinc-carbon" is slightly misleading as it implies that carbon is acting as the oxidizing agent rather than the manganese dioxide. General-purpose batteries may use an acidic aqueous paste of ammonium chloride (NH4Cl) as electrolyte, with some zinc chloride solution on a paper separator to act as what is known as a salt bridge. Heavy-duty types use a paste primarily composed of zinc chloride (ZnCl2). Zinc–carbon batteries were the first commercial dry batteries, developed from the technology of the wet Leclanché cell. They made flashlights and other portable devices possible, because the battery provided a higher energy density at a lower cost than previously available cells. They are still useful in low-drain or intermittent-use devices such as remote controls, flashlights, clocks or transistor radios. Zinc–carbon dry cells are single-use primary cells. Zinc-carbon batteries today have been mostly replaced by the more efficient and safe alkaline batteries. History of the battery By 1876, the wet Leclanché cell was made with a compressed block of manganese dioxide. In 1886, Carl Gassner patented a "dry" version by using a casing made of zinc sheet metal as the anode and a paste of plaster of Paris (and later, graphite powder). In 1898, Conrad Hubert used consumer batteries manufactured by W. H. Lawrence to power what was the first flashlight, and subsequently the two formed the Eveready Battery Company.
À propos de ce résultat
Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.