STTR Phase I: Carbon Nanotube Electrolytic Ultracapacitor

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). This Small Business Technology Transfer Phase I project will demonstrate the feasibility of building and operating a carbon nanotube (CNT) based electrolytic double layer capacitor (EDLC) which incorporates an innovative electrode architecture that will enable unprecedented energy density as well as high power density and low equivalent series resistance. Analysis and preliminary experiments show that an EDLC incorporating the CNT forest electrodes we envision will be capable of providing gravimetric capacitance in the range 200-300 F/g, and energy density in the range 10-100 Wh/kg. The projected energy density will be of particular significance when realized in practice. This is because the energy density range that appears feasible with our design is roughly the same as that typically associated with batteries but unattainable by capacitors. The innovative electrode architecture is also able to provide extraordinarily high areal capacity (measured in Farads per unit device area), which is the energy density performance metric most applicable to power systems for mobile consumer electronics and power management in MEMS and NEMS based devices. Market opportunities in mobile electronics will be targeted where high performance ultracapacitors are needed to provide pulse power support. Applications will then expand to battery replacement as the technology matures. The company's extensive experience with nanodevice fabrication will also be leveraged by targeting applications involving energy storage and power management in MEMS and NEMS scale devices. Applications of this kind are extremely attractive since they will support premium pricing and will be compatible with our use of lithographic patterning for key manufacturing steps. New applications will be targeted as devices become smaller and more specialized, such as in consumer electronics, implantable medical devices, MEMS and NEMS devices, or next-generation spacecraft, for example, where improving the performance of the power source is crucial. With the continuing trend among electronic device manufacturers to increase the power of their products while continuing to scale down product size, the ultracapacitor market should be poised for dramatic growth.