This Small Business Innovation Research Phase I project focuses on establishing the feasibility of supercapacitors with high storage energy density. Current commercial devices, based on carbon electrodes, have low energy density, ~ 5Wh/kg, which limits their commercial potential. The objective of the research is the development of composite electrodes that incorporate nano-scale oxides with significant electrochemical capacitance, and structural robustness. Various fabrication routes will be explored, with the aim of maximizing charge transport and transfer between the different species that form the structure. Electron microscope imaging will be combined with the measurement of the electrochemical capacitance and electrical resistance in order to understand structure-property relations underlying electrochemical energy storage in composite materials. Devices that incorporate the electrodes will also be fabricated and tested. If successful, the project will demonstrate a supercapacitor device with energy density of 25Wh/kg, exceeding that of current devices by a factor of 5. In addition to higher power, longer lifetime is also expected. Other anticipated outcomes are a better understanding of nanoscale metal oxide materials and the interplay between different functional materials, and a demonstration of the technological potential of asymmetric supercapacitors. The broader/commercial impact of this project, if successful, is that supercapacitors with several fold improvement over currently available commercial devices, will find their role in many applications and particularly in transportation. The advent of hybrid and plug-in hybrid technology signals a clear shift towards vehicles, both large and small, that need to be energy efficient while also maintaining full functionality. First generation high energy density devices have applications in light electric vehicle applications (electric bicycles and carts), as to provide a more optimal energy source or to provide power assistance. Succeeding generations of these devices would replace conventional batteries in larger scale cars and trucks. These devices would enable the move towards a greener, more energy efficient transportation system, one that would result in lower pollution and less strain on the nation's energy demands
