AbstractBackgroundPorous carbon electrode (PCE) is identified as a highly suitable electrode material for commercial application due to its production process, which is characterized by simplicity, cost‐effectiveness and environmental friendliness. PCE was synthesized using torch ginger (Etlingera elatior (Jack) R.M. Smith) leaves as the base material. The leaves were treated with different concentrations of ZnCl2, resulting in a supercapacitor cell electrode with unique honeycomb‐like three‐dimensional (3D) morphological pore structure. This PCE comprises nanofibers from lignin content and volatile compounds from aromatic biomass waste.ResultsFrom the characterization of physical properties, PCE‐0.3 had an impressive amorphous porosity, wettability and 3D honeycomb‐like structural morphology with a pore framework consisting of micropores and mesopores. According to the structural advantages of 3D hierarchical pores such as interconnected honeycombs, PCE‐0.3 as supercapacitor electrode had a high specific capacitance of up to 285.89 F g−1 at 1 A. Furthermore, the supercapacitor exhibited high energy and power density of 21.54 Wh kg−1 and 161.13 W kg−1, respectively, with a low internal resistance of 0.059 Ω.ConclusionThe results indicated that 3D porous carbon materials such as interconnected honeycombs derived from the aromatic biomass of torch ginger leaves have significant potential for the development of sustainable energy storage devices. © 2023 Society of Chemical Industry.