Ioxus' Hybrid Ultracapacitor Offers Best of Both Worlds

A new hybrid capacitor reportedly offers twice the energydensity of conventional ultracapacitors, making it a candidate for productsranging from flashlights and hand tools to LED systems and start/stop motorsfor automobiles.

Bycombining the best features of ultracapacitors with lithium-ion batteries, thenew hybrid ultracapacitor could enable end products to charge up more quickly,go longer between charges and go for tens of thousands of cycles betweenreplacement. "This offers a significant increase in energy density, and in theworld of ultracapacitors, energy density is key," says Mark McGough, chiefexecutive of Ioxus Inc., maker of the newhybrid capacitor.

Ioxus isbelieved to be one of two companies worldwide that is now making a hybridlithium-ion ultracapacitor. The key to doing so is the company's ability tofind an electrolyte that is compatible with the product's two electrodes, oneof which is made from a lithium-ion material. "Having an electrolyte that canprovide optimum performance and not destroy either of the electrodes - that'sthe secret sauce," McGough says.

He says thehybrid product offers an energy density of about 4 Wh/kg, whereas conventionalultracaps are closer to 2 Wh/kg.

The technology could beparticularly useful in light-emitting diode (LED) applications because LEDs usefar less electrical current than conventional incandescent bulbs.

"Instead ofgetting 10 minutes of light in your flashlight that's powered by a conventionalultracapacitor and a light bulb, you can combine this with an LED and get threehours of light," McGough says. "And not only do you get longer duration of illumination,but you get quick charge capability, too." He adds that a pair of the hybridcapacitors could power a flashlight for three hours on a 90-second charge.

McGough contendsthat a hybrid ultracapacitor the size of a lunch bucket could power astart/stop system in an automobile. He believes that the technology could playa big role there as automakers adopt start/stop technology in the next fewyears. He also foresees the technology serving in wind turbines, off-gridlighting and other automotive applications, including power windows and doorlocks.