Reporting their results in the journal Nanotechnology, the scientists from Korea University have demonstrated such a high-performance supercapacitor. High-power performance was achieved using aligned carbon nanotubes with a straight and regular pore structure, which is significantly advantageous compared with the more conventional use of activated carbon with a tortuous and irregular pore structure. The well defined pore structure greatly improves the accessibility of ions to the surface of the electrode materials and, as a result, benefits the power characteristics of supercapacitors.

A high energy density was achieved using non-aqueous electrolytes, such as organic electrolyte or ionic liquid, which have operating voltage windows that are about three times wider than that of aqueous electrolytes. Also, opening the tip of the carbon nanotubes by a mild oxidation process led to a further increase in specific capacitance and energy density. The energy density is proportional to the capacitance and to the square of the operation voltage.

More information can be found in the journal Nanotechnology.