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 1.8V and exhibited excellent performance such as a high capacitance of 78.2Fg−1 at a current density of 1Ag−1 in 1.0M Na2SO4 aqueous electrolyte, a relatively high energy density of 34.7Whkg−1 and power density 26.8kWkg−1. In addition, the device exhibited good electrochemical stability, with approximately 91.2% retention of initial specific capacitance after 2000cycles. The asymmetric supercapacitor represents an exciting direction for enhancing the electrochemical performance of supercapacitors and designing next-generation high-performance energy storage devices.