摘要
Hard carbon is the most commercially viable anode material for sodium-ion batteries(SIBs),and yet,its practical imple-mentation remains constrained by insufficient low-voltage plateau capacity,a critical parameter governing storage capacity.This study introduces a targeted component removal and chemical etching strategy to precisely tailor the porous structure ofhard carbon and thus remarkably enhance the plateau capacity.In this strategy,alkaline-dissolved components are removed toform a closed-pore core with tunable size.Subsequently,the in situ occupied alkaline engineers the pore structure throughchemical etching.The optimized hard carbon material not only has short-range disordered graphite domains to facilitate Na^(+)ions'intercalation and deintercalation but also has abundant micropores and closed-pore structures with appropriate pore sizesand an ultrathin carbon layer(1−3 layers)to significantly increase the sodium storage sites.The resulting hard carbon delivers ahigh reversible specific capacity of 389.6 mAh g^(−1)with a low-voltage plateau capacity as high as up to 261.5 mAh g^(−1)and aninitial Coulombic efficiency of 90.7%.Crucially,this cost-effective methodology shows broad precursor adaptability acrosslignocellulosic biomass,establishing a universal paradigm for designing high-performance carbonaceous anodes for SIBs.
基金
the National Key Research and Development Program(2023YFE0109600)
the State Key Laboratory of Advanced Papermaking and Paper-based Materials(2023PY03,2023C07,and 2024ZD02)
the Central Guidance Fund for Local Scientific and TechnologicalDevelopment(2024ZY0012)。
