Nickel zinc, secondary applications

As with the primary battery systems, significant performance improvements have been made with the older secondary battery systems, and a number of newer types, such as the silver-zinc, the nickel-zinc, nickel-hydrogen, and lithium ion batteries, and the high-temperature system, have been introduced into commercial use or are under advanced development. Much of the development work on new systems has been supported by the need for high-performance batteries for portable consumer electronic applications and electric vehicles. Figure 22.1 illustrates the advances achieved in and the projections of the performance of rechargeable batteries for portable applications. 

The vendor states that MBS stabihzes heavy metals in soil, slndges, slag, ash, baghonse dnst, and sediment. Among the heavy metals treatable by the MBS process are arsenic, cad-minm, chrominm, copper, lead, mercnry, nickel, silver, and zinc. MBS technology is applicable in the following indnstries primary and secondary smelters, battery mannfactnrers and recyclers, ferrons and nonferrons fonndries, mnnicipal solid waste incinerators, anto and metal scrap recyclers, electronic mannfactnrers, electroplaters, ceramic prodnct mannfactnrers, and mineral refiners and processors. 

The manufacture of secondary batteries based on aqueous electrolytes forms a major part of the world electrochemical industry. Of this sector, the lead-acid system (and in particular SLI power sources), as described in the last chapter, is by far the most important component, but secondary alkaline cells form a significant and distinct commercial market. They are more expensive, but are particularly suited for consumer products which have relatively low capacity requirements. They are also used where good low temperature characteristics, robustness and low maintenance are important, such as in aircraft applications. Until recently the secondary alkaline industry has been dominated by the cadmium-nickel oxide ( nickel-cadmium ) cell, but two new systems are making major inroads, and may eventually displace the cadmium-nickel oxide cell - at least in the sealed cell market. These are the so-called nickel-metal hydride cell and the rechargeable zinc-manganese dioxide cell. There are also a group of important but more specialized alkaline cell systems which are in use or are under further development for traction, submarine and other applications. 

Tartarie acid [(/ ,/ )-20J is one of the most inexpensive chiral compounds available even the (.S. .S )-enantiomer, which does not occur so frequently in nature, is comparatively inexpensive, so there is no need for laboratory synthesis. Most diesters of both enantiomers are also inexpensive, at least for the C, - C3 alcohols. Tartaric acid itself has been used for the chiral modification of the surface of Raney nickel, which permits highly enantioselective reduction of carbonyl groups, e.g., of oxo esters, to the secondary alcohols (Section D.2.3.I.). The zinc salt of tartaric acid has been used for the asymmetric ring opening of epoxides by thiolates (Section C.). The diesters, e.g., 21-25, are conveniently obtained by acid-catalyzed esterification28-31, a method applicable to almost all alcohols as a typical example, dicyclohexyl (f ,tf)-tartrate is given32. 

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