Three dimensional graphene/carbonized metal-organic frameworks based high-performance supercapacitor

A supercapacitor is a device which can store electrical energy on conductive materials with a highly porous structure. Carbon-based electrochemical capacitors exhibit fast charge/discharge rate and high power density but limited by low energy density compared with lithium ion batteries. We used the self-assembly method to construct a three-dimensional graphene-based nanoporous carbon derived from graphene/carbonized metal-organic frameworks composite, which exhibits a high specific surface area (1849 m2 g−1) and a remarkable capacitance of 472 F g−1 at 1 mV s−1 and 420 F g−1 at 1 A g−1 in aqueous electrolyte. The specific capacitance of 397 F g−1 at 1 A g−1 measured in the organic electrolyte with voltage window up to 3 V leads to a high energy density of 124.1 Wh kg−1 achieved in a symmetrical capacitor device. The progress of this material is close to the theoretical capacitance of carbon-based material (550 F g−1) and readily scalable to practical applications.