EV Battery Technology Shows Promise
A French company is currently developing a new energy storage device that may potentially see itself in electric vehicles. The company, called NAWA (short for NAno technology to fight against global Warming), is currently developing “ultra-capacitors” for use as storage devices that can be rapidly charged and discharged to match demands from electric vehicles. The ultra-capacitors are aiming to help some of the current limitations put on electric car batteries such as poor energy density and limitations on charging and discharging. The ultra-capacitors will be designed to be extremely efficient and may eventually have energy densities that rival current lithium celled batteries. Currently, the ultra-capacitors have superior energy density to current capacitor based energy storage and much better efficiency. NAWA is developing the ultra-capacitors using a state of the art technique that aligns series of carbon nanotubes in rows to allow the electrons to pass through the capacitor with limited resistance. A good analogy to the alignment of the nanotubes is to consider the uniform positioning of bristles on a toothbrush, providing a direct route for the electrons to travel through the ultra-capacitor.
Two current issues with electric vehicles that are concerning for would-be consumers deal with the allowable range that electric vehicles are limited to, and how to charge the vehicle when the battery is drained. The new ultra-capacitors aim to help these two issues by allowing for current electric vehicle batteries to be lighter in weight, more efficient, and able to take a recharge more quickly. To deal with vehicle range limitations and rapid recharging, the carbon ultra-capacitors will supplement current lithium batteries with superior energy density and the ability to regenerate charge through vehicle decelerations, otherwise known as regenerative braking. Current regenerative braking is not very efficient, mostly because the battery cells cannot recouperate from such rapid recharging. New carbon ultra-capacitors will be able to accommodate the rapid recharging that occurs by regenerative braking, thus recollecting otherwise lost energy. Rapid charging will also be possible when using batteries enhanced with the new carbon ultra-capacitors, therefore reducing the amount of time spent waiting for an electric vehicle’s battery to be recharged. NAWA’s ultra-capacitors are still under development, but plans for testing in automotive applications is scheduled within the next five years.
-taken from www.sae.org
Tags: batteries, electric vehicles, energy