O- AND Zn-SELF-DUAL-DOPED POROUS CARBON DERIVED FROM FRUIT WASTE FOR BOOSTING SUPERCAPACITOR PERFORMANCE

Recent developments in supercapacitor devices have prompted an increasing demand for energy storage devices that operate at a micro-scale. Fabrication of such devices requires environmentally benign, compatible materials derived from waste-food industries. Therefore, this study aims to develop a carbon functional self-dual-doped from waste-food industries of mangosteen peel sources to optimize volumetric level supercapacitor. A simple integrated pyrolysis with ZnCl<sub>2</sub> assistance was applied to synthesize the self-dual-doped porous carbon. The precursor was designed as a thin-tubelike additive-free form at a constant density of 1.21 g cm<sup>-3</sup>. The optimized material (CNR-OZn-5) exhibited a unique morphology from a combination of short nanofibers and a unique reef-like architecture. Furthermore, it had a surface area of 670.569 m<sup>2</sup> g<sup>-1</sup> with O (6.00%) and Zn (0.31%) doped. In the two-configuration system, the measuring electrodes yielded capacitive properties of 261 F g<sup>-1</sup> and 315.81 F cm<sup>-3</sup> at 1 A g<sup>-1</sup>. At 10 A g<sup>-1</sup>, the coulombic efficiency and rate capability were 98% and 67.56% with an enhanced pseudo-capacitance contribution of 20.9% and low resistance of 0.05 Ω. The specific energy in the symmetrical supercapacitors system was 13.14 and 16.17 Wh L<sup>-1</sup> in 1 M H<sub>2</sub>SO<sub>4</sub> electrolyte. This new strategy, coupled with the use of waste-food-derived self-dual-doped carbon materials, holds significant potential for achieving high-level volumetric characteristics in sustainable energy storage system.