石油焦炭基储钠材料层间距扩大与闭孔研究OA北大核心CSTPCD

Petroleum coke(PC)is a valuable precursor for sodium-ion battery(SIB)anodes due to its high carbon content and low cost.The regulation of the microcrystalline state and pore structure of the easily-graphitized PC-based carbon is crucial for creat-ing abundant Na+storage sites.Here we used a precursor transformation strategy to increase the carbon interlayer spacing and gener-ate abundant closed pores in PC-based carbon,significantly increasing its Na+storage capacity in the plateau region.This was achieved by introducing a large number of oxygen functional groups through mixed acid treatment and then using high-temperature carbonization to decompose the oxygen functional groups and rearrange the carbon microcrystallites,resulting in a transition from open to closed pores.The optimized samples provide a large reversible capacity of 356.0 mAh g-1 at 0.02 A g-1,of which approxim-ately 93%is below 1.0 V.Galvanostatic intermittent titration(GITT)and in-situ X-ray diffraction(XRD)analysis indicate that the sodium storage capacity in the low voltage plateau region involves a joint contribution of interlayer insertion and closed pore filling processes.This study presents a comprehensive method for the development of high-performance carbon anodes using low-cost and highly aromatic precursors.