Char of Tagetes erecta (African marigold) flower as a potential electrode material for supercapacitors

Abstract

A char of Tagetes erecta flowers (TFC) was derived through simple thermal decompo­sition of Tagetes erecta flowers (TF). Physico-chemical properties of as-prepared TFC were evaluated using XRD, FESEM, FTIR, TGA, N2 adsorption-desorption isotherm analysis and water contact angle measurements. The practicality and applicability of TFC as promising electrode material in supercapacitors (SCs) were evaluated in full-cell configuration by performing electrochemical characterizations like CV, GCD and EIS on a lab-scale TFC-based symmetric SC. TFC exhibited a remarkable specific capacitance of 118.4 F g-1 at a constant current density of 0.2 A g-1 and a specific energy of 4.1 Wh kg-1 at specific power of 0.1 kW kg-1. TFC showed excellent cyclic stability by retaining 92 % of its initial capacitance even after 6000 GCD cycles at 2 A g-1. The superior capacitive behaviour and cyclic stability of TFC could be attributed to its good wettability towards water. This excellent supercapacitive performance of TFC estab­lishes it as a potential floral waste-derived carbon-based electrode material for SCs.

Keywords

• Biochar
• gel polymer electrolyte
• flower waste
• electric double layer capacitor (EDLC)
• carbon cloth
• hydrophilicity