Electrochemical capacitors (ECs) are a promising class of energy-storage devices that bridge the performance gap between conventional capacitors (high-power) and batteries (high-energy). We enhance the performance of ECs by a redesign of the electrode architecture, whereby conformal, nanoscale metal-oxide (MnOx, FeOx, TiO2,or LiMn2O4) coatings are homogeneously distributed throughout the macroscopic thickness (70 to 300 �m) of pre-formed carbon-nanofoam scaffolds. The nanoscopic nature of the metal-oxide coating enables charge�storage capacities that are higher than typically observed for the respective oxides in powder-composite electrodes, while the integrated electron-wiring and plumbing of the carbon nanofoam scaffold facilitates rapid charge�discharge of the oxide. The MnOx�carbon and FeOx�carbon nanofoams function as complementary electrodes in 2-V aqueous asymmetric ECs that deliver relevant specific energy (13 W h kg�1) and power (500 W kg�1) within a 1�100-s timeframe for charge�discharge, while also maintaining the cost and safety advantages associated with the use of a moderate-pH aqueous electrolyte.This work was supported by the Office of Naval Research. I acknowledge experimental and intellectual collaboration on this work with my colleagues Jeffrey W. Long, Bradley T. Willis, and Debra R. Rolison (NRL), Jean Marie Wallace and Katherine A. Pettigrew (Nova Research, Inc.), Azzam N. Mansour (Naval Surface Warfare Center?Carderock Division), and Steven G. Greenbaum (Hunter College).

Enhancing the performance of aqueous asymmetric electrochemical capacitors via a redesign of the electrode architecture

243rd National Meeting (2012)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.