A startup called EnerG2 recently started building a factory in Oregon to produce materials that could improve ultracapacitors for batteries and energy-storage devices. The factory is being funded with $21.3 million from the U.S. Department of Energy as part of a $2.4 billion grant program authorized by the Recovery Act of 2009. The grant was intended to speed up the production and deployment of electric vehicles in the United States, but it’s not clear that battery manufacturers and automakers will have much use for the material in the next few years.
The Seattle-based company says its material–a form of activated carbon used in electrodes–can improve the performance of ultracapacitors. These devices store a fraction of the energy of batteries, but can deliver larger bursts of power and survive many more charge and discharge cycles. Ultracapacitors are being used now in applications such as hybrid buses and wind turbines (to adjust the pitch of the blades). EnerG2 says the materials could also be used in advanced batteries and suggests that its technology could be the key to “making gasoline obsolete.”
The company’s technology is based on a new way to make the activated carbon materials used in ultracapacitor electrodes. Currently, commercial ultracapacitors are made from organic sources–one common source is coconut husk. But the original organic material can contain impurities that limit the voltage of the ultracapacitors. EnerG2’s materials are synthetic, made by a process that lets the company vary the qualities of the ultracapacitor.
For example, changing the size and shape of the nanoscale pores in the material can increase surface area, which can increase energy-storage capacity. Or the company can manipulate the degree to which an electrical charge flows freely through the material, allowing it to deliver varying bursts of power. And the fact that the material contains fewer impurities could allow ultracapacitor makers to redesign their energy-storage devices to operate at higher voltages, which could increase energy capacity by about 20 percent. Eventually, the material could cut the cost per watt-hour for some ultracapacitors in half. “This is not one of those nanotechnologies that is too expensive to be commercializable,” says Rick Luebbe, CEO of EnerG2.