摘要
As by-products of petroleum refining,heavy oils are characterized by a high carbon content,low cost and great variability,making them competitive precursors for the anodes of potassium ion batteries(PIBs).However,the relationship between heavy oil composition and potassium storage performance remains unclear.Using heavy oils containing distinct chemical groups as the carbon source,namely fluid catalytic cracking slurry(FCCS),petroleum asphalt(PA)and deoiled asphalt(DOA),three carbon nanosheets(CNS)were prepared through a molten salt method,and used as the anodes for PIBs.The composition of the heavy oil determines the lamellar thicknesses,sp^(3)-C/sp^(2)-C ratio and defect concentration,thereby affecting the potassium storage performance.The high content of aromatic hydrocarbons and moderate amount of heavy component moieties in FCCS produce carbon nanosheets(CNS-FCCS)that have a smaller layer thickness,larger interlayer spacing(0.372 nm),and increased number of folds than in CNS derived from the other three precursors.These features give it faster charge/ion transfer,more potassium storage sites and better reaction kinetics.CNS-FCCS has a remarkable K^(+)storage capacity(248.7 mAh g^(-1) after 100 cycles at 0.1 A g^(-1)),long cycle lifespan(190.8 mAh g^(-1) after 800 cycles at 1.0 A g^(-1))and excellent rate capability,ranking it among the best materials for this application.This work sheds light on the influence of heavy oil composition on carbon structure and electrochemical performance,and provides guidance for the design and development of advanced heavy oil-derived carbon electrodes for PIBs.
作为石油炼制过程的副产品,重质油具有含碳量高、成本低、可调性强等特点,是构建钾离子电池电极材料极具竞争力的前驱体。然而,重质油组分组成与其电化学储钾性能之间的关系仍不明确。本研究选用具有不同组分组成的重质油(催化裂化油浆、石油沥青和脱油沥青)作为碳源,通过熔盐法制备了3种碳纳米片作为钾离子电池负极材料。研究结果表明,重质油的四组分组成会导致不同的片层厚度、sp^(3)-C/sp^(2)-C比率和缺陷水平,进而对其储钾性能产生重要的影响。其中,催化裂化油浆芳香烃含量高、重组分含量适中,衍生的炭纳米片(CNS-FCCs)具有更小的片层厚度、更大的层间距(0.372 nm)和更多的褶皱缺陷,这些结构特征有助于促进电荷/离子的传输扩散,增加储钾位点并促进反应动力学。CNSFCCs作为钾离子电池负极材料具有出色的K+存储能力(在0.1 A g^(-1)下循环100次后比容量为248.7 mAh g^(-1))、长循环寿命(在1.0 A g^(-1)下循环800次后比容量为190.8 mAh g^(-1))和优异的倍率性能,在报道的炭材料中综合性能位于前列。本研究揭示了重质油组分对炭材料结构及其电化学性能之间的影响机理,对设计和开发高效的重质油衍生钾离子电池碳基电极材料具有指导意义。
出处
《新型炭材料（中英文）》
SCIE
EI
CAS
CSCD
北大核心
2024年第5期1003-1014,共12页
New Carbon Materials
基金
国家自然科学基金(22208375、22138013)
青岛市关键技术攻关及产业化示范类项目(24-1-4-xxgg-6-gx)
山东省泰山学者项目(ts201712020)
中国“万人计划”科技领军人才项目(W03020508).
