石油沥青作为炼油副产品被用作多种碳质材料前驱体,但在高温碳化过程中易石墨化,不利于钠离子储存。将酚醛树脂引入硬质沥青共碳化,促进沥青分子与酚醛树脂分子间的交联,抑制碳层熔融重排,得到酚醛树脂改性沥青基硬碳材料。当酚醛树脂添加质量比例为1∶1时,在1 200℃碳化所得硬碳材料具有最佳的储钠电化学性能。在0.05 A/g电流密度下,比容量达270.2 mAh/g,首次库仑效率为63.8%。在0.3 A/g电流密度下,循环1 200圈后容量保持率达71.6%。

Hard carbon is regarded as the most promising anode material for sodium-ion batteries (SIBs) due to its high specific capacity and good cyclic stability.As a by-product of oil refining,petroleum asphalt is commonly used as a precursor for various carbonaceous materials.However,its tendency to graphitize during high-temperature carbonization limits its application for sodium-ion storage.To address this issue,the co-carbonization of hard asphalt with phenolic resin is proposed.This strategy promotes cross-linking between asphalt and phenolic resin molecules,preventing carbon layers from melting and rearrangement.Consequently,a hard carbon material based on phenolic resin-modified asphalt is obtained.Notably,the hard carbon material obtained at 1 200℃ with a phenolic resin addition ratio of 1∶1 yields the best electrochemical performance for sodium-ion storage,which exhibits a specific capacity of 270.2 mAh·g^-1 at a current density of 0.05 A·g^-1,and delivers an initial coulomb efficiency (ICE) of 63.8%.Moreover,the capacity retention rate remains at 71.6% even after 1 200 cycles under a current density of 0.3 A·g^-1.

李旭东(1998-),男,硕士生,研究方向为钠离子电池负极材料,1228653185@qq.com;赵青山(1987-),男,博士,副教授,研究方向为能量储存与转化、新型碳纳米材料、非均相催化,通讯联系人,qszhao@upc.edu.cn。