Porous carbon@MnO2 and nitrogen-doped porous carbon from carbonized loofah sponge for asymmetric supercapacitor with high energy and power density

The development and utilization of biomass materials for high-performance energy storage electrode materials that meet the urgent need for green and sustainable development strategies are required. In this study, we developed a simple thermal treatment method for the formation of porous carbon (PC) from loofah sponge. An asymmetric supercapacitor was then assembled depending on the loofah sponge-derived PC@MnO2 and N-doped PC, providing high energy and power density than MnO2. The working voltage of the designed asymmetric device could reach 1.8 V and exhibited excellent performance such as a high capacitance of 78.2 F g(-1) at a current density of 1 A g(-1) in 1.0 M Na2SO4 aqueous electrolyte, a relatively high energy density of 34.7 Wh kg(-1) and power density 26.8 kW kg(-1). In addition, the device exhibited good electrochemical stability, with approximately 91.2% retention of initial specific capacitance after 2000 cycles. The asymmetric supercapacitor represents an exciting direction for enhancing the electrochemical performance of supercapacitors and designing next-generation high-performance energy storage devices. (C) 2015 Elsevier B.V. All rights reserved.