Lead-acid secondary batteries components

To transport people and material growing transportation systems are needed. More and more of the energy for these systems is drawn from secondary batteries. The reason for this trend is economic, but there is also an environmental need for a future chance for electric traction. The actual development of electrochemical storage systems with components like sodium-sulfur, sodium-nickel chloride, nickel-metal hydride, zinc-bromine, zinc-air, and others, mainly intended for electric road vehicles, make the classical lead-acid traction batteries look old-fashioned and outdated. Lead-acid, this more than 150-year-old system, is currently the reliable and economic power source for electric traction. 

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. 

Once received at a secondary smelter, a lead-acid battery undergoes several processing stages to recover and treat the various component parts. In most modern plants, automatic battery breakers are used to process and recover these parts. There are many variations to battery-breaking operations throughout the world, although the outputs obtained from each operation are similar, namely, battery pastes, metallic fractions, acid, plastic components. 

Lead-acid batteries, after consumer use, do not typically release aU of their lead contents into environmental dispersion channels. Instead, the lead content of much lead-acid battery production is recycled. This is not to say that the cmder forms of battery recycling are or have not been associated with waste streams, particularly at the breaking phase where lead components are first recovered for eventual secondary smelting. Unsecured disposal on land of battery acid containing lead provides not only plumes of the metal in toxic bioavailable forms but also mobility for it as the acid retards soil binding of lead. That recycling, often classified as part of scrap lead inventories, is a significant contributor to secondary lead production. As seen in various tables in Chapter 3, secondary lead production over recent decades has become a major part of total production. 

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