Activated carbon from wasp hive for aqueous electrolyte supercapacitor application

In this work, a honeycomb-like hierarchical porous activated carbon derived from a sustainable wasp hive was produced by single-step chemical activation with potassium carbonate (K2CO3) as an activating agent at 800 degrees C for 1 h. The activated carbon was tested as a supercapacitor electrode for energy storage. The chemical activation with K2CO3 tailored the topography and surface properties to realize an amorphous macro-meso-microporous activated carbon material with a specific surface area of 765 m2/g and an average pore diameter of 2.4 nm. The highest specific capacitance (225 F/g) in 3-electrode cells was obtained in an acid electrolyte, whereas the neutral and alkaline electrolytes have lower specific capacitance. The wasp hive activated carbon electrode presented specific energy of 5.33 Wh/kg at 0.25 A/g, which exceeds the specific energy of a commercial activated carbon at the same conditions. About 100% coulombic efficiency was achieved with capacitance retention of 83.6% after 5000 charge/discharge cycles.

Automated summary

A honeycomb-like hierarchical porous activated carbon derived from a sustainable wasp hive was produced using potassium carbonate as an activating agent, showing high specific capacitance in acid electrolyte. The activated carbon electrode demonstrated specific energy exceeding commercial activated carbon, with excellent cycling stability achieving about 100% coulombic efficiency and 83.6% capacitance retention after 5000 charge/discharge cycles.