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This doesn't need clarification. Stated reasons for clarification were that a month was too long a time frame because of fast initial voltage drop. Thats not self discharge. That's just a battery returning to open circuit voltage after charging. A month is if anything a shorter timeframe than typically used. Other reason was the person asking for clarification didn't understand the use of the term low self discharge. Low self discharge is a type of NiMH battery. It would be indicated on the b... Tags: Mobile edit Mobile web edit |
→History: Reason for requesting clarification not valid. Difficult to understand logic behind request. Tags: Mobile edit Mobile web edit |
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{{See also|History of the battery}}
Work on NiMH batteries began at the [[Battelle Memorial Institute|Battelle]]-Geneva Research Center following the technology's invention in 1967. It was based on [[sintering|sintered]] Ti<sub>2</sub>Ni+TiNi+x alloys and NiOOH electrodes.
Interest grew in the 1970s with the commercialisation of the [[nickel–hydrogen battery]] for satellite applications. Hydride technology promised an alternative, less bulky way to store the hydrogen. Research carried out by [[Philips|Philips Laboratories]] and France's [[French National Centre for Scientific Research|CNRS]] developed new high-energy hybrid alloys incorporating [[rare-earth metal]]s for the negative electrode. However, these suffered from alloy instability in [[alkaline]] [[electrolyte]] and consequently insufficient cycle life. In 1987, Willems and Buschow demonstrated a successful battery based on this approach (using a mixture of La<sub>0.8</sub>Nd<sub>0.2</sub>Ni<sub>2.5</sub>Co<sub>2.4</sub>Si<sub>0.1</sub>), which kept 84% of its charge capacity after 4000 charge–discharge cycles. More economically viable alloys using [[mischmetal]] instead of [[lanthanum]] were soon developed. Modern NiMH cells were based on this design.<ref name="rdjapan">{{cite journal | last1=Nii | first1=K. | last2=Amano | first2 = M. | year = 1997 | title = R & D of Hydrogen Absorbing Alloys in Japan | journal = Acta Metallurgica Sinica | volume = 10 | issue = 3 | pages = 249–255 | url = http://www.amse.org.cn/EN/abstract/abstract13633.shtml | access-date = 10 September 2011}}</ref> The first consumer-grade NiMH cells became commercially available in 1989.<ref>[http://www.economist.com/displaystory.cfm?STORY_ID=10789409 In search of the perfect battery], ''[[The Economist]]'', 6 March 2008.</ref>
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