Synthesizing biomass into nano carbon for use in high-performance supercapacitors - A brief critical review

Abstract

The ability to store electrical energy is crucial for meeting the demands of energy security and sustainability. However, the storage of electricity remains a significant challenge in today's world. To address this challenge, energy storage systems are being utilized. These systems include a range of electrochemical energy storage devices such as batteries, fuel cells, capacitors, and supercapacitors. According to various research studies, supercapacitors have the highest power density and lowest energy density among all electrochemical energy storage systems. A significant challenge in developing supercapacitors is achieving a higher energy density while maintaining power density and cycle stability. A supercapacitor is an electrochemical unit comprised of an anode, cathode, electrolyte, and separator. Activated carbon is the most widely used carbon electrode material due to its low cost, although other carbon materials have excellent electrochemical properties. Improving the specific capacitance of carbon materials by adjusting the pore structure, wettability, and specific surface area has limited option at present. Carbon materials suitable for supercapacitors should have a high specific surface area of around 2000–3000 m2/g and a pore size of approximately 2–5 nm. In addition, researchers discovered that in supercapacitor electrode materials, micropores (<2 nm) exhibit superior performance compared to mesopores (2–50 nm). According to various reviews, the analysis of the electrode has indicated a specific energy range of 1–10 Wh/kg and a specific power range of 500–10,000 W/kg. This paper discusses the use of agro biomass for making the base material for the formation of effective electrodes for use in supercapacitors. The technology promotes waste reutilization by turning waste into useful products, providing a strong economic basis for using supercapacitors.