Electrode materials for supercapacitors: A comprehensive review of advancements and performance

The mounting concerns headed for energy consumption and the need for efficient energy storage have drawn considerable attention. Supercapacitors are emerging as pivotal technology as it provides quick charge/ discharge rates and acts as a bridge between batteries and conventional capacitors. This heightened interest in supercapacitors stems from their potential to address the pressing challenges associated with energy storage and pave the way for more sustainable and responsive energy systems. Supercapacitors fill the gap between batteries and capacitors in terms of energy density and power density and open a wide field for applications. Along with high power density than batteries, it comes with relatively more energy density than capacitors. Supercapacitors are envisioned to bring a paradigm shift since their emergence as they are having longer life cycles, wide operating temperature ranges, relatively low cost and are eco-friendly. They are widely used in various applications such as energy harvesting, automotive industries, power generation, wireless charging etc. Despite having such advantages, the energy density is not enough to meet the required demand and sometimes it is also used as short- term energy storage device. The performance of supercapacitors can be enhanced by modifying their electrode material, electrolyte or dielectric material used. This article has described different types of electrodes along with their specific capacitances. Recent progress and advances in electrode materials such as carbon-based, metal oxides, polymers, MXenes, transition metal dichalcogenides, black phosphorus, etc., and their composites have been described in detail. Different properties of supercapacitors such as specific capacitance, current density, cyclic stability, etc. for various kinds of electrodes have been discussed in manuscript.