Recently in hybrid electric vehicles the batterys

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recently, in hybrid-electric vehicles, the battery’s relatively low energy and high mass were somewhat limiting factors to the distance a vehicle can travel (called the range) on battery alone and the vehicle’s acceleration. However, recent innovation in the form of a lithium-ion battery, has allowed vehicle makers to greatly extend their vehicles range without excessive mass: The first production car to use lithium-ion batteries was the Toyota Vitz CVT 4, a small car sold only in Japan. It used a four-cell, 12 ampere-hour lithium-ion battery pack to power its electric accessories and restart the engine after idle stop. More recently, Tesla Motors, in San Carlos, Calif., has offered the Tesla Roadster, an all-electric sports car that uses 6831 lithium-ion cells, each roughly the size of a double-A battery. They give the car up to 400 km (250 miles) of range, as well as the breathtaking acceleration of 0 to 100 kilometers per hour (0 to 60 miles per hour) in less than 4 seconds. 24 Lithium-ion batteries are a promising technology for highly efficient, all-electric vehicles because they produce a lot of energy for their mass – 150 Wh/kg, compared with 100 Wh/kg for nickel metal hydride (the previous battery technology for hybrid-electric vehicles) and 25 Wh/kg for lead-acid batteries. 25 To make lithium-ion batteries practical for mass-produced electric-drive vehicles, new technologies must increase the energy the batteries store and the speed with which they can discharge it. They must also lengthen cycle life to 15 years or 241 000 km (150 000 miles) - the average life of a vehicle. Finally, they must keep the cost as low as possible. However, before lithium-ion batteries are ready for wide-spread use in vehicles, there are a few improvements to be made: 26 Lithium-ion batteries’ high energy capacity for their low mass also makes them suitable in mobile devices such as laptop computers and mobile phones. Lithium-ion batteries’ components materials and reactions are summarised in Table 12.3. Table 12.3: Component materials and reactions in lithium-ion batteries Component materials Anode : lithium graphite (LiC 6 ) Cathode : lithium cobalt oxide (LiCoO 2 ) Electrolyte : lithium hexafluorophosphate (LiPF 6 ) aqueous organic solution Reactions Anode (half) : LiC 6 C 6 + Li + + e Cathode (half) : CoO 2 + Li + + e LiCoO 2 Overall : LiC 6 + CoO 2 C 6 + LiCoO 2 Source : Bergveld, H.J., Kruijt W.S. and Notten P.H.L. (2002); 27 Dhameja, S. (2001) 28 24 Voelcker, J. (2007) ‘Lithium Batteries for Hybrid Cars’, IEEE Spectrum Online . Available at . Accessed 16 May 2008. 25 See Everything2 – Energy Density at . Accessed 16 May 2008. 26 Voelcker, J. (2007) ‘Lithium Batteries for Hybrid Cars’, IEEE Spectrum Online . Available at . Accessed 16 May 2008.
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  • Spring '14
  • Bruner,StevenDouglas
  • Batteries, Mole, Rechargeable battery, Lithium-ion batteries, Natural Edge Project

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