The efficient use of energy produced from alternative energy sources and the uninterrupted delivery of energy to consumers reveals the importance of energy storage. Intensive studies are carried out on supercapacitors, which willsoon replace batteries in the energy storage area, owing to their superior properties. In this study, Rheum ribes peel was converted to activated carbon for the first time using carbonization and different activation methods, and three supercapacitor cells were prepared using these materials. The surface characterizations of the obtained electrode materials were performed using scanning electron microscopy with energy-dispersive X-ray, Brunauer–Emmett–Teller and X-ray diffraction analysis methods. The best specific capacitance value was obtained for the RRP-pure electrode and was 70.82 F g$^{-1}$ at a current density of 1 A g$^{-1}$. The cyclic voltammetry curves of electrodes were perfectly obtained and found extremely similar to the ideal supercapacitor curves. The RRP-pure electrode has a maximum energy density of 6.78 Wh kg$^{-1}$ at a power density of 618.86 W kg$^{-1}$ and exhibited good stability. For the all-prepared electrodes, the ion exchange between the electrode materials and the electrolyte was at a good level and equivalent series resistance values of the electrodes were low, leading to a positive advantage in energy transmission. The produced electrodes are cheap, environmentally friendly, efficient, high capacity and stable, making them an excellent alternative to conventional methods in the field of energy storage.