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

•A simple thermal treatment method for the formation of porous carbon from loofah sponge•An asymmetric supercapacitor depends on the porous carbon@MnO2 and N-doped porous carbon.•The working voltage of asymmetric device reaches 1.8 V and exhibits excellent electrochemical performance.

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.

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