Construction of hierarchically porous carbon nanoflowers from wood via a ZnCl2 dissolution - regeneration route for enhanced lon transport and energy storage

A ZnCl 2 dissolution-regeneration route was developed to construct flower-like hierarchically porous carbon from balsa wood. Before carbonization, concentrated ZnCl 2 partially dissolved the surface cellulose and introduced zinc species, while subsequent water regeneration induced the in situ formation and assembly of RCellulose@ZnO nanosheets on the preserved wood scaffold. Regulation of the ZnCl 2 treatment time enabled controlled surface reconstruction. The optimized sample obtained after 2 h of treatment, CRCDW 2 , exhibited a well-developed flower-like nanosheet architecture, hierarchical microporosity or mesoporosity, and a specific surface area of 865.6 m 2 /g. The preserved longitudinal wood channels and reconstructed nanosheet structure provided continuous pathways for electrolyte penetration and ion transport, together with accessible charge-storage sites. CRCDW 2 delivered a specific capacitance of 139.9 F/g at 1 A/g and retained 89.28% of its initial capacitance after 3300 cycles at 5 A/g. The Zn//CRCDW 2 zinc-ion hybrid supercapacitor exhibited a specific capacitance of 27.86 F/g and an energy density of 3.87 Wh/kg at a power density of 78.13 W/kg. These results demonstrate that precursor-level surface reconstruction can integrate the natural transport architecture of wood with a controllable hierarchical carbon structure for electrochemical energy storage.