The environmental degradation and hazard to human life caused by the depletion of fossils fuels and the urgent need for sustainable energy sources to meet the rising demand in energy has led to the exploration of novel materials that are environmentally friendly, low cost and less hazardous to human life for energy storage application using the green chemistry approach. Herein, we report on the transformation of the readily abundant pine cone biomass into porous carbon via KOH activation and carbonization at 800 °C as electrode materials for supercapacitors. The porous carbon material exhibited a mesoporous framework with a specific surface area of 1515 m² g⁻¹, a high voltage window of 2.0 V, a gravimetric capacitance of 137 F g⁻¹, energy density of 19 W h kg⁻¹ and excellent cyclability in neutral 1 M Na₂SO₄ electrolyte for a symmetric carbon/carbon electrode cell. The result shows that the material is robust and shows great promise with neutral electrolytes in high-performance energy-storage devices.

Asymmetric supercapacitor with VS ₂ nanosheets as positive and activated carbon materials as negative electrodes exhibited maximum energy density (42 W h kg ⁻¹ ).

Porous activated carbons was synthesized by an environmentally friendly technique, with an in-depth experimental study carried out to understand the electrochemical behaviour in different aqueous electrolytes (KOH, LiCl, and Na ₂ SO ₄ ).