High Energy Density Electrochemical Capacitors Without Consumption of Electrolyte

We proposed an electrochemical capacitor that consists of a battery/double-layer capacitor or a pseudocapacitor/pseudocapacitor electrode configuration, with charge transferring during the charge and discharge processes. This is fundamentally different from exiting capacitors including conventional double-layer electrochemical capacitors and asymmetrical cells. The ions in the proposed capacitors are shuttled between two electrodes during the charge and discharge cycle. The theoretical energy density of the proposed asymmetric capacitors is as high as 60 W h/kg vs less than 15 and 25 W h/kg for conventional double-layer capacitors and battery/double-layer capacitors, respectively. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3121564] All rights reserved.