Abstract: The present invention is directed to a stable aqueous dispersion of carbon, wherein the carbon comprises between 75-85 wt. % activated carbon, and 15-25 wt. % CNT having a purity of at least 95 wt. %. The dispersion is free of surfactant and is stable for at least two weeks. The aqueous dispersion is useful to make an active layer for an electrode of a supercapacitor. The present invention is also directed to a supercapacitor cell having at least one electrode comprising a current collector and an active layer, wherein the active layer comprises activated carbon and high purity carbon nanotubes and is free of binder. The active layer materials are both porous and conductive in order to increase the charge storage capability and to decrease the electrode resistance. In general, the content of carbon nanotubes in the active layer is between 10 and 30 wt. % and the purity of the carbon nanotubes is at least 95 wt. %.

Abstract: The present invention is directed to a supercapacitor cell having at least one electrode comprising a current collector and an active layer, wherein the active layer comprises activated carbon and high purity carbon nanotubes and is free of binder. The active layer materials are both porous and conductive in order to increase the charge storage capability and to decrease the electrode resistance. In general, the content of carbon nanotubes in the active layer is between 10 and 30 wt. % and the purity of the carbon nanotubes is at least 95 wt. %.