SBIR Phase II: High Power and Energy Density VN-based Asymmetric Supercapacitors

This Small Business Innovation Research (SBIR) Phase II project will demonstrate asymmetric supercapacitors that meet or exceed the cost and performance targets set by the United States Advanced Battery Consortium for FreedomCar applications. These devices will be based on low-cost VN and NiOOH with aqueous electrolytes. Currently available commercial products are based on carbon with organic electrolytes and deliver 3-6 Wh/kg with power densities of 700 W/kg at a cost of ~$0.10 per Farad. The cost must be decreased by at least a factor of two for broader market acceptance, and the energy density improved to reduce the supercapacitor size. The proposed SBIR program will lead to next generation supercapacitors with energy densities that approach 15 Wh/kg and costs that are as much as 10 times lower than those for currently available commercial devices. The superior performance and cost are derived from the use of inexpensive, base metal nitrides and oxides tailored to give high specific capacitance, low impedance aqueous electrolytes that enable fast, efficient high power cycling, and an asymmetric design that maximizes the operating potential window. This combination of performance and cost will enable significant expansion in the use of supercapacitors for a number of important applications. The broader impact/commercial potential of this project lies in efficient peak power management of electric loads, such as automotive start/stop systems, acceleration and regenerative braking of hybrid electric vehicles (HEVs), and uninterruptible power supplies. Supercapacitors offer a combination of energy and power that complements other electrochemical storage and conversion devices, including batteries and fuel cells. With improvements in energy density and reductions in cost, the markets for supercapacitors are expected to grow rapidly. Transportation and smart grid applications represent large markets with>30% annual growth. The automotive supercapacitor market totaled $55 million in 2009 and could grow to $243 million by 2015, fueled by the demand for HEVs. The smart grid market for supercapacitors is forecasted to reach $2.5 billion in 2015 driven by peak-load management and regenerative braking for light rails. The devices developed during this SBIR program could support minimizing our nation?s production of greenhouse gases and dependence on foreign energy sources. Federal agencies including the Department of Defense will also benefit, in particular, for applications such as extended range vehicles, exoskeleton systems, and electromagnetic armors.