High Energy Density and Long Cycle Life Ultra-Capacitors

Capacitive energy storage devices based on double-layer capacitance or pseudocapacitance have attracted much attention in recent years because of their wide variety of potential applications. High Surface area activated carbon represents a typical material for double-layer capacitance, while Ru0(2) is the best example of pseudocapacitance. Extensive efforts have been devoted to the development of electrochemical capacitors based on either activated carbon or Ru0(2). However, both materials have their disadvantages and limitations. Activated carbon has high surface area, but its double-layer capacitance is low. In addition, a large portion of the surface area is non-accessible to the electrolyte. It is difficult to achieve high energy density with activated carbon as the electrode material. With the conventional processing technology, it is difficult to make Ru0(2) with high surface area. More importantly, Ru0(2) is too expensive to be used for large scale commercial applications. Phase I will fabricate high surface area aerogels of low cost and conductive metal oxides as electrode materials for capacitive energy storage cells. We expect that electrochemical capacitors made from the aerogel materials will have light weight, high energy density, long life cycle, and low cost.