|
A zinc–carbon battery is a dry cell battery that delivers a potential of 1.5 volts. Although carbon is an important element of the battery's construction, it takes no part in the electrochemical reaction. The cell could more properly be called a "zinc–manganese" cell. The zinc can is the anode and the source of high potential electrons and hence it is the negative pole. The manganese dioxide and carbon black paste is the cathode and the inert carbon rod is a non-corrodible conductor that makes the positive pole. General purpose batteries may use ammonium chloride and/or zinc chloride as the electrolyte. Zinc–carbon batteries were the first commercial dry batteries, developed from the technology of the wet Leclanché cell (), and made flashlights and other portable devices possible, because the battery can function in any orientation. 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, since they are not intended to be recharged. ==History== By 1876, the wet Leclanché cell was made with a compressed block of manganese dioxide. In 1886 Dr. Carl Gassner patented a "dry" version by using a zinc cup as the anode and making the electrolyte with a paste of plaster of Paris (and later, wheat flour) to gel and immobilize the electrolyte. 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 Ever Ready battery company. In 1900 Gassner demonstrated dry cells for portable lighting at the World's Fair in Paris. Continual improvements were made to the stability and capacity of zinc–carbon cells throughout the 20th Century; by the end of the century the capacity of a zinc–carbon cell had increased fourfold over the 1910 equivalent.〔David Linden, Thomas B. Reddy (ed). Handbook Of Batteries 3rd Edition. McGraw-Hill, New York, 2002 ISBN 0-07-135978-8 Chapter 8〕 Improvements include the use of purer grades of manganese dioxide, better sealing, and purer zinc for the negative electrode. Zinc chloride cells (usually marketed as "heavy duty" batteries) use a paste primarily composed of zinc chloride, which gives a longer life and steadier voltage output compared with ammonium chloride electrolyte. Manufacturers must now use more highly purified zinc to prevent local action and self-discharge Zinc-carbon batteries still account for 20% of all portable batteries in the UK, and 18% in the EU.〔() Monthly battery sales statistics – MoETI – March 2011〕〔() INOBAT 2008 statistics.〕〔() Battery Waste Management – 2006 DEFRA〕〔() EPBA Sustainability Report 2010〕 In Japan they account for only 6% of all primary battery sales, and only 7% of all types of batteries sold in Switzerland. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Zinc–carbon battery」の詳細全文を読む スポンサード リンク
|