It is still needed to enhance the energy density without sacrificing power density and cycle stability for supercpacitors. Here an asymmetric supercapacitor is fabricated by employing a 3D bio-inspired porous carbon (BPC) as the negative electrode materials while a MnO2/3D BPC nano-composite as the positive electrode. The 3D BPC is created from a biomass-based waste of litchi rind through a simple strategy of hydrothermal process in alkaline solutions. The carbon material possesses a high specific surface area (1326 m2 g-1), hierarchical pore size distributions and good electrical conductivity (3.8 S cm-1), which endow a remarkable electrochemical performances as supercapacitor electrode. The optimized 3D BPC-based electrodes show a high specific capacitance of 379 F g-1, and the MnO2/3D BPC nano-composite also exhibits the excellent electrochemical performances. Using two 3D bio-inspired porous carbons-enhanced electrode materials, the MnO2/BPC//3D BPC asymmetric supercapacitor is assembled by the best industry practice method. The MnO2/BPC//3D BPC asymmetric cell displays an enhanced energy density of 53 Wh kg-1 at a power density of 365 W kg-1 while remains an energy density of 24 Wh kg-1 even at a high power density of 25,000 W kg-1 based on the electrode materials in aqueous electrolyte system, which is among the best ever reported aqueous asymmetric systems. 83% of the initial capacitance is maintained after 2000 cycles at 2 A g-1 in the aqueous asymmetric systems. Moreover, the packaged MnO2/BPC//3D BPC asymmetric supercapacitor can cross the performance gap between electrochemical capacitor and Ni-metal hydride batteries.

Bio-inspired synthesis of 3D porous carbons-enhanced electrode materials for high-performane asymmetric supercapacitors

249th National Meeting (2015)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.