The energy density of conventional electric double-layer capacitors is about 6-7 Wh/kg and due to the
limited specific capacitance and cell voltage, and a large amount of electrolyte which is required to build
a layer of charge of the double-layer. The energy density theory guide clearly shows that the energy
density of double-layer capacitors is ultimately limited by how many ions are available in the electrolyte
or the salt concentration in the electrolyte.
We demonstrate a lithium-ion capacitor, which is capable of achieving high energy density over 20
Wh/kg, long cycle life and high power density. The lithium-ion capacitor consists of a battery electrode
with lithium intercalated hard carbon anode and a double-layer activated carbon cathode electrode with
the open-circuit potential at or near the maximum potential when the cell is fully charged. The stabilized
lithium metal powder was applied onto the surface of prefabricated hard carbon anode electrodes.
Short Biography: Dr. Jim P. Zheng is Sprint Eminent Scholar Chair and Professor at the Department of
Electrical and Computer Engineering of Florida State University. He obtained his Ph.D. degree from the
State University of New York at Buffalo in 1990. He has worked at US Army Research Laboratory for
about 5 years. He has published more than 200 articles in scholarly journals and conference proceedings.
He has won numerous research grants from many governmental agencies such as NSF, DOE, DOD, and
NASA totaling more than $14 M.
5|Page