The AP has a decent high-level overview of the "ultracapacitor" technology from EEStor, an as-yet-untested, quick-charging capacitor that its inventors claim will replace batteries entirely.
EEStor's secret ingredient is a material sandwiched between thousands of wafer-thin metal sheets, like a series of foil-and-paper gum wrappers stacked on top of each other. Charged particles stick to the metal sheets and move quickly across EEStor's proprietary material.
Previous attempts to improve ultracapacitors have focused on improving the metal sheets by increasing the surface area where charges can attach.
EEStor is instead creating better nonconductive material for use between the metal sheets, using a chemical compound called barium titanate. The question is whether the company can mass-produce it.
Extraordinary claims require extraordinary evidence, reminded Carl Sagan. Until EEStor's products are in the hands of independent testers, we can only cross our fingers.
Although much of the initial talk about the ultracapacitor technology refers to its use in electric cars, smaller versions could also be used to power quick-charging gadgets like phones and MP3 players.