Abstract
A series of flexible and self-standing coal-derived carbon fibers (CCFs) were fabricated through electro-spinning coupled with carbonization using bituminous coal and polyacrylonitrile (PAN) as the carbon precursors.These CCFs were utilized as free-standing lithium-ion battery (LIB) anodes.Optimizing car-bonization temperature reveals that the CCFs exhibit a one-dimensional solid linear structure with a uni-form distribution of graphite-like microcrystals.These fibers possess a dense structure and smooth surface,with averaging diameter from approximately 125.0 to 210.0 nm at carbonization temperatures ranging from 600 to 900 ℃.During electrospinning and carbonization,the aromatic rings enriched in bituminous coal crosslink with PAN chains,forming a robust three-dimensional (3D) framework.This 3D microstructure significantly enhances the flexibility and tensile strength of CCFs,while increasing the graphite-like sp2 microcrystalline carbon content,thus improving electrical conductivity.The CCFs carbonized at 700 ℃ demonstrate an optimal balance of sp3 amorphous and sp2 graphite-like carbons.The average diameter of CCFs-700 is 177 nm and the specific surface area (SSA) is 7.2 m2 g-1.Additionally,the fibers contain oxygen-containing functional groups,as well as nitrogen-containing func-tional groups,including pyridinic nitrogen and pyrrolic nitrogen.Owing to its characteristics,the CCFs-700 showcases remarkable electrochemical performance,delivering a high reversible capacity of 631.4 mAh g-1.CCFs-700 also exhibit outstanding cycle stability,which retains approximately all of their first capacity (400.1 mAh g-1) after 120 cycles.This research offers an economical yet scalable approach for producing flexible and self-supporting anodes for LIBs that do not require current collectors,binders and conductive additives,thereby simplifying the electrode fabrication process.
维普
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