Supercapacitors based on carbon materials and ionic liquids

This paper presents performance of supercapacitor built from different carbon materials. The general principle of supercapacitor and formula connected with its operation are also described. The role of carbon nanotexture has been underlined selecting carbons prepared by template techniques. It has been demonstrated that mainly micropores and small mesopores play important role for charging of electrical double layer, however, interconnectivity of pores is crucial for charge propagation. The presence of heteroatom, e. g. nitrogen in the carbon network is profitable because of additional reversible faradaic reactions. A linear dependence of capacitance values vs nitrogen content has been found. Ionic liquids are presently considered as a novel generation of electrolyte with interesting properties, e. g. a high operating voltage. An increase of supercapacitor voltage (over 3V) has been realized by application of ionic liquids based on phosphonium salt.