High Performance Ultracapacitors for Spacecraft

ABSTRACT: This SBIR Phase I project is targeted at the development of a novel ultracapacitor using ionic liquid electrolytes. Commercially available ultracapacitors exhibit high power density, in excess of 6000 Wh/kg, but relatively low energy density of under 10 Wh/kg. Boulder Ionics proposes to develop a ultracapacitor with an energy density of over 30 Wh/kg through the use of ionic liquid electrolytes and nanostructured electrodes. Ionic liquids have very wide electrochemical stability windows, up to 6 V. As the energy density of ultracapacitors depends on the square of the operating voltage, ultracapacitors using ionic liquid electrolytes could offer energy densities three times those of commercial ultracapacitors with organic electrolytes. In Phase II, Boulder Ionics will demonstrate a novel ultracapacitor design using ionic liquid electrolytes. To address the cost-effectiveness and ultimate commercial potential of the design, Boulder Ionics will also demonstrate an innovative high-throughput, low-cost synthesis method for the electrolyte. BENEFIT: The new ultracapacitor power supply will increase the lifetime and capability of advanced spacecraft. Unlike batteries, ultracapacitors can provide hundreds of thousands of cycles, increasing the lifetime and reducing the life cycle cost of satellites, particularly for those in low earth orbit. In addition, the higher power density of ultracapacitors will enable increased capability, including higher power burst communications, actuators and thrusters. Commercial applications of high-energy ultracapacitors include windmill blade pitch drives, vehicle starting, hybrid-electric vehicles, grid-scale energy storage, backup power supplies and cameras. Ultracapacitors developed in this program are expected to have widereaching impacts on U.S. energy security and balance of trade.