STTR Phase I: Synthesis of multifunctional nanofibrous polyaniline/carbon composites

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 develop novel multifunctional materials based on polyaniline (PAni) nanofibers (PANFs) and carbon nanofibers(CNFs) for energy storage. Although PAni composites have been reported for a wide range of applications, including sensors, biosensors, photoelectrochromic cells, etc., due to their excellent electrical, thermal and mechanical properties, none capitalize on the enhanced properties expected from the combination of PANF with CNF. PANFs have greater electronic conductivity than PAni nanospheres and nanorods and can be synthesized on a variety of substrates. Solarno will use a proprietary process for synthesizing composites of PANFs on CNFs. In Phase I Solarno will use these composites as electrode materials for asymmetric supercapacitors, an enabling technology that provides both high energy and power, with the specific technical objectives of: synthesizing and characterizing PANFs on CNF substrates, and achieving supercapacitor performance of 15 Wh/kg, 10 kW/kg and >10 cycles, thus far exceeding current lead acid batteries in terms of power and cycle life. In Phase II we will improve the energy density of these devices to enable potential replacement of such batteries, and explore other functions for the composites, such as sensors and electro-chemical devices. The PANF/CNF composites developed by Solarno will be introduced to the supercapacitor market via materials sales, and partnering/licensing arrangements, and later to related electrochemical functions/applications. Solarno is targeting requirements of the Hybrid Electric Vehicle (HEV) market for its initial supercapacitor designs, and as such, the ultimate customers will be major automobile manufacturers. The market requires that capacitors provide higher energy density, reduced size, higher reliability, and lower cost. Commercially available EDLCs commonly provide energy densities around 4 Wh/kg, and power densities between 15-21 kW/kg. The supercapacitor developed here can excel in this market by providing energy density > 25 Wh/kg and better reliability (>2.0 x 104 cycles); the Phase I work will optimize the properties of our PANF/CNF composite to meet this goal. The supercapacitors will also be well-suited for load-leveling for renewable energy sources; direct societal benefits will come from improving the viability of HEVs and renewable sources, tied to reductions in fossil fuel consumption, providing bridge power for wind and solar power farms, and partially replacing lead acid storage batteries. The results of this work in optimizing PAni composites for supercapacitors will translate well into improved functionality for other applications.