Low-temperature Highly Graphitized Porous Biomass-based Carbon as an Efficient and Stable Electrode for Lithium-ion Batteries and Supercapacitors

Graphite is a widely used fossil material valued for its versatility, thanks to its excellent thermal and electrical conductivity as well as high chemical stability. Producing graphitic carbon from biomass offers a promising alternative to fossil graphite, but the process requires extremely high temperatures—up to 3000  °C—leading to significant energy consumption. In this work, we report a greener and more sustainable low-temperature method (900 °C) for the synthesis of highly graphitized biomass carbon using pure boron as a catalyst and logging residues (LR) as a carbon source. The work focuses on the correlation between the structural transformation of the precursors into graphitic carbon and their corresponding electrochemical characteristics as electrodes for lithium-ion batteries (LIBs) and supercapacitors. The carbons were prepared in two steps, i.e., carbonization at 500 °C with boron, followed by activation with KOH at 900 °C. A control carbon, produced using the same method but without boron, was used for comparison. The physicochemical characterization results demonstrated the successful graphitization of the LR-based carbon. In addition, the carbon materials exhibited highly porous structures with specific surface areas (BET) of 2645 m² g^-1 for the boron-treated carbon (BCLR), and 3141 m² g^-1 for the control carbon (CLR). The CLR and BCLR electrodes tested in LIBs delivered specific capacities of 386 and 505 mAh g^-1 at a 1 C rate at the end of 200 cycles, respectively. CLR and BCLR electrodes were also tested for supercapacitors, delivering specific capacitances of 87 and 144 F g^-1 at a current rate of 1 A g^-1, respectively. This work opens a gateway for a straightforward and cost-effective synthesis method for scaling up biomass-based carbon electrodes for LIBs and supercapacitors, facilitating sustainable precursors and an industrially viable approach.