Storing energy without chemical reactions allows ultracapacitors to charge and discharge much faster than batteries. (Image credit: Maxwell Technologies)
Hang around the energy storage crowd long enough, and you’ll hear chatter about ultracapacitors. Tesla Motors chief executive Elon Musk has said he believes capacitors will even “supercede” batteries.
What is it that makes ultracapacitors such a promising technology? And if ultracapacitors are so great, why have they lost out to batteries, so far, as the energy storage device of choice for applications like electric cars and the power grid?
Josie Garthwaite 