Material Detail

The science and technology of ultracapacitors are reviewed for a number of electrode materials, including carbon, mixed metal oxides,

and conducting polymers. More work has been done using microporous carbons than with the other materials and most of the

commercially available devices use carbon electrodes and an organic electrolytes. The energy density of these devices is 3–5 Whrkg

with a power density of 300–500 Wrkg for high efficiency Ž90–95%. chargerdischarges. Projections of future developments using

carbon indicate that energy densities of 10 Whrkg or higher are likely with power densities of 1–2 kWrkg. A key problem in the

fabrication of these advanced devices is the bonding of the thin electrodes to a current collector such the contact resistance is less than 0.1 2

V cm .