Lignocellulosic oxidation bridging to modulate pseudographitic domain of hard carbon toward boosted sodium storage

Lignocellulosic biomass-derived hard carbons (HCs) have drawn significant industrial focus as the notably promising anode candidates for Na-ion batteries. However, it poses an arduous hurdle to optimize the carbon microstructure toward advanced sodium energy. Herein, we propose a lignocellulosic oxidation bridging approach to modulate the pseudographitic microstructure for HCs toward high performance anode materials. Oxygen-containing functional groups are introduced to sterically bridge the aromatic compound fragments and unsaturated aliphatic hydrocarbons of biomass, thereby inhibiting ordered rearrangements of carbon interlayers during pyrolysis. The as-optimized HCs feature a desirable short-range pseudographitic domain with expanded carbon interlayer spacings. The favorable microstructure enables HCs to display an enhanced capacity of 309 mAh g⁻¹ accompanied by a commendable initial Coulombic efficiency of 82.7 % and a durable longevity of over 1800 cycles. Charge storage mechanism and practical feasibility of HCs are systematically explored by in situ Raman test and full cells. This work puts forward a tractable strategy to facilitate the progress of advanced biomass-derived HCs for Na-ion batteries.