Thursday 13 May 2010

Battery Technology Used In EVs


A battery is the most expensive and least environmentally friendly component of an electric car. It is a real pain - a hurdle that keeps the electric motoring from development. Using the knowledge we posses, we cannot make an EC travel further than 120 miles between recharges.
With such a low range it is and remains limited by city borders not giving us the real mobility and flexibility. Is there a chance we could come up with a new electric car battery that gives us a better range? Let's first look at the known and available options.
1.    Lead-Acid Batteries
Although Alessandro Volta invented a battery in 1800, it was 1859 when a lead-acid prototype was created by Gaston Plante. These batteries are robust, tolerant to abuse, tried and tested and because of their low cost.
Ø  For higher power applications with intermittent loads however, Lead acid batteries are generally too big and heavy and they suffer from a shorter cycle life and typical usable power down to only 50% Depth of Discharge (DOD). Despite these shortcomings Lead acid batteries are still being specified for Power Net applications (36 Volts 2 kWh capacity) because of the cost, but this is probably the limit of their applicability and NiMH and Li-Ion batteries are making inroads into this market.
Ø  Lead-acid batteries are composed of a Lead-dioxide cathode, a sponge metallic Lead anode and a Sulphuric acid solution electrolyte. This heavy metal element makes them toxic and improper disposal can be hazardous to the environment.
The cell voltage is 2 Volts 

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