Biowaste assisted preparation of self-nitrogen-doped nanoflakes carbon framework for highly efficient solid-state supercapacitor application

Porous carbon materials synthesized from renewable and biowaste resources are receiving a lot of interest due to their various applications, economic benefit, and proper waste management. Recently, a variety of biological precursors have been utilized to create self-heteroatom-doped carbon materials. Mangifera indica is known as one of the world's most significant tropical fresh fruits in total global production. Peels are a by-product and account for around 20 % of the total fruit weight whose removal has become a major issue. In this study, the self-heteroatom-doped porous carbon (H-PC) skeleton has been synthesized using simple KOH activation and pyrolysis process. Different characterizations are applied to evaluate the effects of temperatures and stoichiometric amounts of KOH on the morphology, pore structure, and content of heteroatom in carbon skeleton. Moreover, it shows a maximum specific capacitance ( C sp ) of 402 F g −1 with 1 A g −1 in acidic electrolytes and also it works in neutral electrolytes. The fabricated solid-state symmetric supercapacitor (SS-SC) device demonstrates excellent durability up to 10,000 cycles with the highest energy density (47 Wh kg −1 ) and a power density (14.3 kW kg −1 ) even in acidic electrolytes. This study shows new relationships between environmental improvement by waste management, biowaste conversion, and proper use of renewable energy. Graphical representation of the synthesized activated H-PC from biowaste M. indica peels which is used as active electrode materials for electrochemical storage application. • Heteroatom-doped porous carbon (H-PC) materials have been synthesized from biowaste Mangifera indica peels. • Heteroatoms, higher surface area and pore volume influence the capacitive performances. • Electrokinetic analysis deliberates the prime capacitive involvement to amass the overall charge. • SS-SC device displays significant specific capacitance with a maximum energy density and power density. • SS-SC device shows outstanding durability at a higher current density.