The growing interest in supercapacitors has arisen from their potential application as electrical storage devices operating in parallel with batteries to provide high power densities. Electrochemical supercapacitors fill the gap between batteries and conventional capacitors in terms of their specific energy and specific power. The energy stored in these devices mainly comes from either the electrical double-layer capacitance of materials with high specific surface areas or the faradaic pseudocapacitance of electroactive materials with several oxidation states (1,2). Based on the type of supercapacitance to be utilized, supercapacitors can be made from various materials. A double layer supercapacitor usually uses activated carbon (3) as the electrode material, while a redox supercapacitor uses either noble or transition metal oxides in aqueous electrolytes (4-9).
展开▼
