3D Prussian blue decorated porous carbon composite electrode for advanced asymmetric supercapacitor applications

Abstract

Irrational use of fossil fuels led to global warming and pollution. Therefore, the newer technologies should be sustainable and eco-friendly to combat climate change. In this context, supercapacitors (SCs) are demonstrated with carbon materials derived from natural biomaterials. The utilization of biomass-derived materials in energy storage not only converts biowaste material to value-added products but also reduces the production cost. Although SCs exhibit high power density, they are not considered a primary energy source due to their poor energy density. By taking advantage of the present work's asymmetric configuration, the operating voltage window and energy density of aqueous SCs are significantly enhanced. An asymmetric SC is developed by combining a porous 3D cubical-shaped Prussian blue (PB) decorated carbon derived from tamarind seeds (ACTS-800) (PB/ACTS-800) positive electrode with ACTS-800 negative electrode and aqueous 3 M KNO3 electrolyte. The resulting ACTS-800//PB/ACTS-800 (1:2) asymmetric SC demonstrated a broad electrochemical stable voltage window of 2.2 V in the aqueous medium. Impressively, a high energy density of 60 Wh/kg @ 551 W/kg realized is much superior to most of the carbon/carbon SCs operated in an aqueous medium.