Nanoarchitectonics with beetroot peel waste derived activated carbon for improved electrochemical performances in supercapacitors using redox additive electrolyte

Supercapacitors are presumed to be ideal for electrochemical energy storage high power applications because they are an intermediate between conventional capacitors and batteries. Various bio-derived activated carbon was venerated for enhanced supercapacitor application and the electrochemical performance of carbon-based materials in aqueous electrolytes was further enhanced to a greater extent with the incorporation of redox additives. In this work, the activated carbon obtained from beetroot is explored as the electrode material for supercapacitors with redox additives in electrolytes. The chemical functionalities and elements present in the prepared activated carbon were confirmed using FT-IR and XPS, respectively. The electrochemical energy storage behavior of the prepared activated carbon was analyzed with hydroquinone (HQ) as a redox additive. The specific capacity of the prepared electrode in 0.01 M HQ/H₂SO₄ at 3 A/g is 2589 C/g. The calculated power and energy density of the fabricated symmetric cell with HQ/H₂SO₄ at 3 A/g are 2356 W/kg and 36 Wh/kg, which is superior to the mere 1 M H₂SO₄ electrolyte with the gravimetric power and energy density of 1800 W/kg and 13.5 Wh/kg, respectively.