Wood-derived carbon/CNT aerogel composites for LiS batteries: enhanced polysulfide adsorption and electrochemical kinetics

The development of free-standing hosts represents an effective strategy for enhancing the energy density and cycling stability of lithium‑sulfur (Li S) batteries. This study proposes a CNT aerogel-modified wood-derived carbon skeleton as a free-standing host for Li S battery cathodes. The anisotropic microchannels of wood are preserved to accelerate electrolyte transport, while the homogeneous filling of CNTs within these microchannels introduces abundant active sites for polysulfide adsorption and a large specific surface area for sulfur loading. Additionally, this design significantly improves the electrical conductivity. The free-standing CBW/CNT@S cathode demonstrated a high initial discharge capacity of 1218.2 mAh g −1 and excellent cycling stability (retaining 900.4 mAh g −1 after 100 cycles at 0.1C). Even at 0.5C, it maintained 509.8 mAh g −1 after 600 cycles. Under a high sulfur areal loading of 7.96 mg cm −1 , a discharge capacity of 664.5 mAh g −1 was achieved. Electrochemical impedance spectroscopy and cyclic voltammetry at varying scan rates confirmed enhanced electrochemical kinetics and improved polysulfide adsorption ability. Overall, the synergistic integration of CNTs with wood-derived carbon hosts serves as a validated strategy for optimizing Li S battery performance, providing foundational insights for the rational design of next-generation energy storage systems.