Pineapple stem‐derived porous carbon for symmetrical supercapacitor: evaluation of the effect of activating agent on physicochemical and capacitive characteristics

Abstract Background Owing to the increasing demand for effective energy storage solutions to promote the transformation towards renewable energy sources, research on the development of electrode materials for supercapacitor devices has significantly increased. In this study, we promote a facile, eco‐friendly and sustainable strategy for fabricating electrode materials from pineapple stem waste for supercapacitors via one‐step chemical activation at high temperature. The pineapple stems were activated using KOH, NaOH and ZnCl 2 at molarity level of 0.5 mol L −1 , then heated at 800 °C for 3 h under N 2 protection to produce pineapple stem‐based activated carbon (PSC). Results PSC‐K (activated with KOH) exhibits the highest S BET value of 945 m 2 g −1 and V tot of 0.475 cm 3 g −1 . To evaluate the electrochemical activity of the supercapacitors, devices were designed with different constructions, i.e. symmetric and asymmetric. The PSC‐K‐based symmetric supercapacitor device exhibits a high specific capacitance of 255 F g −1 at 1 A g −1 . Further, PSC‐K also delivered an optimum E d of 35.45 Wh kg −1 at a P d of 1.06 kW kg −1 , and E d of 22.63 Wh kg −1 at a P d of 20.37 kW kg −1 . Conclusion This work provides ubiquitous biomass‐derived active carbon that can be widely used as electrode material in supercapacitors for future prospects. © 2025 Society of Chemical Industry (SCI).