Averrhoa bilimbi leaves-derived oxygen doped 3D-linked hierarchical porous carbon as high-quality electrode material for symmetric supercapacitor

This successfully performed a facile one-way KOH impregnation strategy, to hierarchically prepare interconnected porous carbon and self-oxygen doped from Averrhoa bilimbi leaves waste, as binder-free electrode material (PCBLs) for high-quality symmetrical supercapacitor. 3D porous structure and surface area PCBLsderived controlled by different KOH concentrated solution. KOH infiltrated into precursor as act activation agent to completely removed inorganic impurities, result high carbon content of 85.54-87.22% with oxygen functional group of 10.61-14.71%. The precursor impregnated at 0.5 mol/L possessed excellent micropores 87.69%, adjusting mesopores and appropriate amounts of oxygen doped of 14.71%. As a result, it performed high performance of symmetrical supercapacitor. Furthermore, the electrochemical performance was evaluated within a two-electrode system using a binder-free solid coin design in different aqueous electrolytes of 1 M H2SO4, NaOH, and Na2SO4, respectively. This indicated that the symmetric supercapacitor-based PCBL-5 had a high specific capacitance of 293 F g-1 in 1 M H2SO4 aqueous electrolyte at a current density of 1.0 A g-1. It also showed impressive energy densities of 26.54, 21.85, and 16.12 Wh kg- 1 in 1 M H2SO4, NaOH, and Na2SO4, at an optimum power density of 178.44 W kg- 1. The observed desirable excellent material and electrochemical behaviors of the new source hierarchical porous carbon derived from Averrhoa bilimbi leaves waste would be a competitive candidate as electrode material in the development of high-quality supercapacitor devices.

Automated summary

This study successfully utilized a simple KOH impregnation strategy to prepare porous carbon material from Averrhoa bilimbi leaves waste, and applied it as a binder-free electrode material for high-quality symmetrical supercapacitors. The results showed excellent electrochemical performance, with high specific capacitance and energy density in different aqueous electrolytes. This material derived from waste Averrhoa bilimbi leaves has the potential to be a competitive electrode material for high-quality supercapacitor devices.