Eco-friendly production of carbon electrode from biomass for high performance Lithium and Zinc ion capacitors with hybrid energy storage characteristics

Biomass derived carbon has emerged as promising electrode material for supercapacitors, owing to its low-cost, abundance and eco-friendly nature. Herein, we investigate the application of fluorine-enriched carbon derived from Ipomoea carnea as electrode in Zinc-Ion and Lithium-Ion capacitors (ZIC and LIC). The prepared IC is activated using KOH to enhance the surface properties and to create an amicable environment to accommodate metal ions. The properties of resultant biomass carbon (IC) are evaluated using various physical and chemical characterization techniques. The activated IC exhibited high surface area of 736.7 m2/g and suitable porous structure. The IC electrode is paired with Zn metal foil and an aqueous solution of ZnSO4/MnSO4 is used to fabricate ZIC. The device exhibits a capacitance of 168 F g-1 and retains about 79.5% of its initial capacitance after 5000 cycles. The prepared IC pre-lithiated and used to fabricate Li Ion capacitor, which delivered a capacitance of 155 F g-1 and retained 77.5% of initial capacitance after 5000 cycles. The implication biomass-derived carbon in LIC and ZIC is experimented in detail.