Heteroatom-Doped Biomass-Derived Porous Carbon for Supercapacitor Applications: A Review

Abstract

The increasing demand for high-performance energy storage technologies poses significant challenges to conventional materials, particularly regarding the need for enhanced energy and power output in symmetric supercapacitors. This review explores the potential of biomass-derived porous carbon as a solution, emphasizing the role of heteroatom doping in combating these challenges. By introducing various heteroatoms-including oxygen (O), nitrogen (N), phosphorus (P), sulfur (S), and boron (B)-into the carbon matrix, recent research has demonstrated significant improvements in material wettability, pore structure optimization, and overall electrochemical performance. Specifically, strategies utilizing dual and multi-heteroatom doping, such as N/O, P/O, S/O, N/S, N/O/S, N/O/P, N/P/S, N/P/B, O/P/S, and N/O/P/S, have been shown to generate synergistic effects that markedly enhance energy storage capacity and electrical conductivity compared to traditional single-atom doping schemes. The review provides a comprehensive evaluation of the energy storage capacity, cycling stability, and energy/power output associated with heteroatom-doped activated carbons. Key insights reveal that achieving a uniform pore distribution, along with the establishment of hierarchical connections between 2D and 3D nanostructures, is vital for optimizing electrochemical performance. Importantly, the incorporation of heteroatoms not only augments electrical conductivity but also facilitates more efficient electrochemical reactions-essential elements for the development of high-performance supercapacitors. The integration of 3D nano-hierarchical pores and multi-doping heteroatoms delivers outstanding supercapacitor performance, with a capacitance of 401 F/g and an impressive energy output of 76 W/kg in a symmetric 2-electrode configuration. This performance firmly positions it as a competitive alternative to commercial batteries. In conclusion, this review highlights the innovative structural modifications and doping strategies employed in biomass-derived carbon materials, including synthesis processes crucial for generating unique 2D and 3D architectures. By detailing these methods and their contributions to improving the energy density of mixed electrical double-layer capacitors (EDLCs) and pseudocapacitors, this review underscores the competitive potential of these biomass-derived materials when compared with traditional energy storage devices such as batteries. Future research directions could focus on optimizing these methodologies further and exploring commercial viability in large-scale applications.