Premium Power (October 1998)

Asymmetric Supercapacitor Based Upon Nanostructured Active Materials

Sponsor: US Nanocorp, Inc.

• Project Performance Period: 3/1/1999 - 2/28/2002
• Total project (est.): $900,000.00
• Requested ATP funds: $441,000.00

Today's supercapacitors, while offering the high burst-power performance important to next-generation mobile electronics, suffer from low energy capacity when compared to batteries. A joint venture led by US Nanocorp aims to change this by developing a new kind of supercapacitor with energy densities (20 watt-hours per kilogram) comparable to that of batteries while delivering superior burst power and virtually unlimited cycle life (more than 100,000 recharges.) The technology developed by this project will be broadly enabling for many uses, including cell phones, uninterruptible power supplies, and eventually hybrid gasoline/electric automobiles. The joint venture also includes JME, Inc. (Shaker Heights, Ohio); Florida Atlantic University (Boca Raton, Fla.); and Eveready Battery Co. (Westlake, Ohio). Unlike today's devices that use two electrodes of the same material, this project will use asymmetric electrodes--made of different materials--yielding a device with double the capacitance of conventional capacitors and eight times the energy storage capability. To achieve the high surface areas needed for high capacitance, the partners propose to make their electrodes with nanostructured materials--particles whose size is on the order of billionths of a meter. The supercapacitors will owe much of their advanced performance to the vast surface areas that nanoparticles afford--just one gram of nanostructured carbon has an amazing surface area of 400 square meters. In striving for one of the first practical applications of nanotechnologies, US Nanocorp and Florida Atlantic will advance the state of the art in developing novel anodes and cathodes in a whole new supercapacitor device structure. The partners face the challenge of demonstrating that nanomaterials can be made with good electrochemical and physical properties in a working supercapacitor device. JME will design, fabricate, and evaluate prototypes, and Eveready will conduct full-scale test evaluations. The new supercapacitors are anticipated to replace batteries in many applications, offering the advantages of an almost indefinite number of charge/discharge cycles; rapid cycling (over 100 times a second); high currents (over 2,000 amps); no maintenance; and non-toxic, relatively inexpensive components. A successful project is expected to yield a myriad of new applications to portable electronic devices and create new basic technologies contributing to battery improvements and nanostructured materials development.

For project information:

Dr. David E. Reisner, (203) 234-8024
usnanocorp@aol.com

ATP Project Manager

Gerald Castellucci, (301) 975-2435
gerald.castellucci@nist.gov