LAUSR

Abstract Trichoderma is cultivated on a solid medium prepared from wheat straw and food waste. The harvested mixture is fully used to prepare high specific surface carbon. The carbon is further assembled into an electrode to assess its electrochemical performance as a supercapacitor. As adjusted by the activation temperature, the carbon derived at 800 °C displays an extremely high specific surface area of 3977.3 m2 g−1, and the carbon derived at 900 °C shows a large pore volume of 2.372 cm3 g−1. Correspondingly, an excellent specific capacitance of 409.7 F g−1 at a current density of 0.5 A g−1 can be achieved in a three-electrode system. The symmetric supercapacitor achieves a high energy density of 11.3 Wh kg−1 with a corresponding power density of 240.0 W kg−1, and exhibits a good capacitance retention of 99.2% after 10000 cycles at the current density of 5 A g−1 in a 6.0 mol L−1 KOH electrolyte. Based on these results, a novel low-cost path for preparing high-performance materials for energy storage applications is achieved from real-world biomass sources and provides new insights to realize the full utilization of biomass waste.