Sustainable upcycling of bamboo sheath biomass to hierarchical porous carbon for next-generation supercapacitors

The sustainable development of high-performance carbon electrodes from renewable resources is essential for advancing next-generation electrochemical energy storage systems. In this work, we present an efficient strategy for converting bamboo sheath biomass into hierarchically structured porous carbon with a large specific surface area of 1285 m2 g−1. The synergistic integration of interconnected hierarchical porous networks and defect-rich carbon domains facilitates rapid ion diffusion kinetics and provides abundant electroactive sites for charge storage. When evaluated in a three-electrode configuration, the optimized carbon electrode delivers an impressive specific capacitance of 471 F g−1 at 1 A g−1, confirming its excellent intrinsic charge-storage capability. A symmetric two-electrode supercapacitor device further demonstrates the practical applicability of the material, achieving a specific capacitance of 268 F g−1 at 1 A g−1, along with a competitive energy density of 37.2 Wh kg−1 and power density of 515 W kg−1. Notably, the device retains 98.4% of its initial capacitance after 10,000 charge–discharge cycles, underscoring its outstanding long-term electrochemical stability and durability. This study highlights the significant potential of bamboo sheath biomass as a scalable and cost-effective precursor for advanced porous carbon materials and offers an effective pathway toward environmentally benign, high-performance supercapacitors for sustainable energy storage applications.