A renewable carbon material derived from native European deciduous trees serves as a sustainable electroactive substance for multifunctional energy storage systems

Abstract

Carbon derived from biomass, characterized by its abundant porosity and adaptable physical and chemical traits, has emerged as a promising choice for electrode materials in electrochemical energy storage devices like supercapacitors and lithium–sulfur (Li–S) batteries, marking a rapidly advancing field. Herein, we report the creation of a fresh biomass-derived activated carbon produced via a pyrolysis technique using a blend of indigenous European deciduous trees, including Birch, Fagaceae, and Carpinus betulus (commonly referred to as European hornbeam). The biomass-derived activated carbon underwent various material characterizations to scrutinize its structural, morphological, and elemental compositions. Utilizing this biomass-derived activated carbon as the electrode material across different supercapacitor configurations (such as coin cells and printable miniaturized devices) and as sulfur hosts in Li–S batteries paves the way for expanded applications in biomass energy utilization. The supercapacitor devices were successfully fabricated and shown to be operated efficiently within an operational potential range of 2.5 V (0.0–2.5 V) utilizing an EMIMBF₄ ionic liquid electrolyte. The symmetrical coin cell supercapacitor device achieved a notable energy density of approximately 23.52 W h kg⁻¹ when subjected to an applied current density of 0.66 A g⁻¹. Furthermore, Li–S batteries were assembled, incorporating a composite cathode composed of activated carbon derived from biomass and sulfur. Subsequently, cyclic voltammetry alongside charge–discharge assessments at varying scan rates and C-rates were performed, respectively. The sulfur–biomass-derived activated carbon (BAC) composite delivers an initial discharge capacity of 661 mA h g⁻¹ at a C-rate of 0.05C. Long-term cycling tests were conducted at 1C and 0.5C over 500 cycles, achieving coulombic efficiencies of approximately 99% and 97%, respectively, in sulfur–biomass-derived activated carbon composite-based Li–S batteries. Hence, our research showcases the scalable synthesis of biomass-derived activated carbon and its utilization as a versatile electrode material, laying the groundwork for the next generation of multifunctional sustainable energy storage systems.