Carbon-based materials for lithium-ion capacitors
Lithium-ion capacitors (LICs) can deliver high energy density, large power density and excellent stability since they possess a high-capacity battery-type electrode and a high rate capacitor-type electrode. Recently, great efforts have been devoted to fabricating carbon-based electrodes for LICs, which can effectively enhance their electrochemical performance due to the high electrochemical activity of carbon materials. Here, we present the recent developments of carbon-based materials as electrodes of LICs. Carbon-based battery-type materials, which can be either anodes or cathodes, highlighted here include carbonaceous materials, carbon/transition metal compounds, carbon/polyanion composites, carbon/metalloid and metal materials as anodes and carbon/metal compound composites as cathodes. Apart from battery-type electrodes, carbon-based materials also play an important role in the design of capacitor-type electrodes of LICs, which focus on carbonaceous materials as cathodes. The prospects and challenges in this field are also discussed.