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Zinc–air batteries (non-rechargeable), and zinc–air fuel cells (mechanically rechargeable) are metal-air batteries powered by oxidizing zinc with oxygen from the air. These batteries have high energy densities and are relatively inexpensive to produce. Sizes range from very small button cells for hearing aids, larger batteries used in film cameras that previously used mercury batteries, to very large batteries used for electric vehicle propulsion. During discharge, a mass of zinc particles forms a porous anode, which is saturated with an electrolyte. Oxygen from the air reacts at the cathode and forms hydroxyl ions which migrate into the zinc paste and form zincate (), releasing electrons to travel to the cathode. The zincate decays into zinc oxide and water returns to the electrolyte. The water and hydroxyl from the anode are recycled at the cathode, so the water is not consumed. The reactions produce a theoretical 1.65 volts, but this is reduced to 1.35–1.4 V in available cells. Zinc–air batteries have some properties of fuel cells as well as batteries: the zinc is the fuel, the reaction rate can be controlled by varying the air flow, and oxidized zinc/electrolyte paste can be replaced with fresh paste. Zinc-air batteries can be used to replace now discontinued 1.35 V mercury batteries (although with a significantly shorter operating life), which in the 1970s through 1980s were commonly used in photo cameras. Possible future applications of this battery include its deployment as an electric vehicle battery and as a utility-scale energy storage system. == History == The effect of oxygen was known early in the 19th century when wet-cell Leclanche batteries absorbed atmospheric oxygen into the carbon cathode current collector. In 1878, a porous platinized carbon air electrode was found to work as well as the manganese dioxide () of the Leclanche cell. Commercial products began to be made on this principle in 1932 when George W. Heise and Erwin A. Schumacher of the National Carbon Company built cells,〔 〕 treating the carbon electrodes with wax to prevent flooding. This type is still used for large zinc–air cells for navigation aids and rail transportation. However, the current capacity is low and the cells are bulky. Large primary zinc–air cells such as the Thomas A. Edison Industries ''Carbonaire'' type were used for railway signaling, remote communication sites, and navigation buoys. These were long-duration, low-rate applications. Development in the 1970s of thin electrodes based on fuel-cell research allowed application to small button and prismatic primary cells for hearing aids, pagers, and medical devices, especially cardiac telemetry.〔David Linden, Thomas B. Reddy (ed). ''Handbook Of Batteries 3rd Edition'', McGraw-Hill, New York, 2002 ISBN 0-07-135978-8, chapter 13 and chapter 38〕 The first rechargeable zinc air batteries were manufactured in 1996 by a Slovenian innovator Miro Zoric. They were developed to power vehicles using the first AC-based drive trains, also developed by Mr. Zoric. The first vehicles on roads to use zinc air batteries were small and mid-sized buses in Singapore, where Mr. Zoric led the national electrification program at Singapore Polytechnic, during his technology transfer post. The mass production assembly line for his zinc air batteries was put in place in 1997. The cells offered much higher energy density and specific energy (and weight) ratio, compared to then standard lead acid batteries. 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–air battery」の詳細全文を読む スポンサード リンク
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