A Review on Biomass-Derived Activated Carbon for Next-Generation Supercapacitors: Cutting-Edge Advances and Future Prospects

Energy, clean air, and water are essential for human survival, and these elements are interconnected. The harmful effects of modern lifestyles and increasing energy demands have intensified fossil fuel usage. The primary issue is the eventual depletion of fossil fuels, which has shifted the focus to renewable energy. Renewable energy consumption is projected to increase by 300% by 2050 compared to 2010 levels. Moreover, modern electronic devices require long-lasting, lightweight, high-energy, and power-dense storage devices. Supercapacitors (SCs) have garnered considerable attention due to their superior power and energy densities compared to secondary batteries and conventional capacitors, respectively. Activated carbon, due to its high specific surface area (SSA), chemical stability, and unique texture, has become a focal point for energy storage applications. Activated carbons are synthesized from various resources, and biomass-derived activated carbon transforms waste into a valuable product. This is particularly important given the improper disposal of large quantities of biomass waste, especially in developing countries. Therefore, researchers have focused on biomass-derived activated carbon electrodes for SC applications. This review provides an overview of recent advances, synthesis strategies, and the influence of activation methods and agents on the synthesis of activated carbon. Recent developments aimed at improving performance have been highlighted for better understanding. This review identifies future opportunities and trends in the synthesis of activated carbon from various biomass sources.