Biomass-derived N-doping porous carbon spheres by N₂ plasma for lithium-ion batteries

The cost-effectiveness and renewability of biomass-derived carbon spheres have important advantages for wide application, yet efficient synthesis methods and green activation studies are still challenging. Here, hemicellulose from corncobs was extracted, and then N₂ plasma technology was used to modify the carbon spheres produced from hemicellulose in a single process. The effect of hydrothermal reaction parameters on the yield of carbon spheres was investigated, and the optimal preparation conditions were determined with solid–liquid ratio of 1:10 (g/mL), reaction time of 12 h, and pH of 1.5. The modified carbon spheres featured 3.02% nitrogen content and mesoporous structure. As an anode material for a lithium-ion battery, the modified sample has a specific capacity of 232.1 mAh g⁻¹ after 50 cycles at 0.1 A g⁻¹. In this study, biomass-derived carbon spheres containing multifunctional groups were prepared under green and mild conditions, and this innovative process provides an effective basis for the sustainable utilization of biomass.