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An organic radical battery (ORB) is a relatively new type of battery first developed in 2005.〔(【引用サイトリンク】url=http://www.wisegeek.com/what-is-an-organic-radical-battery.htm )〕 This type of battery is generally not available for the consumer, however their development is approaching practical use.〔 ORBs are potentially more environmentally friendly than conventional metal-based batteries, because they use organic radical polymers, which are flexible plastics, instead of metals to provide electrical power. ORBs are considered to be a high-power alternative to the Li-ion battery. Functional prototypes of the battery have been researched and developed by different research groups and corporations including the Japanese corporation NEC.〔 The organic radical polymers used in ORBs are examples of stable radicals, which are stabilized by steric and/or resonance effects.〔 For example, the nitroxide radical in (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO), the most common subunit used in ORBs, is a stable oxygen-centered molecular radical. Here, the radical is stabilized by delocalization of electrons from the nitrogen onto the oxygen. TEMPO radicals can be attached to polymer backbones to form poly(2,2,6,6-tetramethyl- piperidenyloxyl-4-yl methacrylate) (PTMA). PTMA-based ORBs have a charge-density slightly higher than that of conventional Li-ion batteries, which should theoretically make it possible for an ORB to provide more charge than a Li-ion battery of similar size and weight.〔 Current ORB research is being directed mostly towards Hybrid ORB/Li-ion batteries because organic radical polymers with appropriate electrical properties for the anode are difficult to synthesize.〔 ==Applications== ORBs are currently not in commercial use and are still under development. Theoretically, ORBs could replace Li-ion batteries as more environmentally friendly batteries of similar or higher charge capacity and similar or shorter charge time.〔 A major application of ORBs is, therefore, the area of handheld electronic devices. Organic radical batteries were first researched and developed by NEC in 2005 with the intent of being widely used to power tiny gadgets in the near future.〔 They began with a size of 0.3 mm and an extremely quick charge time. Since the beginning of development, smart cards and RFID tags were the main targets for ORB usage. NEC has also worked on a larger 0.7 mm battery which is thicker, but also has a high charge capacity of 5 mAh. Given the fast redox chemistry of nitroxide radicals,〔 ORBs have been shown useful in keeping a computer running momentarily following a power outage. Although the amount of additional time provided is short, it is adequate to allow a computer to backup any crucial data before completely shutting down.〔 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「Organic radical battery」の詳細全文を読む スポンサード リンク
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