脂肪侧链结构对沥青中间相转化过程及其针状焦微观结构的影响  

Effects of aliphatic side groups structures of different pitches on their mesophase transformation and the microstructure of needle cokes

作　　者：张建国 郭建光 陈茜茹 周云辉 卢地胜 李轩科 ZHANG Jianguo;GUO Jianguang;CHEN Qianru;ZHOU Yunhui;LU Disheng;LI Xuanke(State Key Laboratory of Coking Coal Resources Green Exploitation,Pingdingshan 467000,China;Hubei Province Pilot Base on Coal Conversion and New Carbon Materials,Wuhan University of Science and Technology,Wuhan 430081,China;Institute of Coal Mining and Utilization,China Pingdingshan Coal Stock Co.,Ltd.,Pingdingshan 467000,China)

机构地区：[1]炼焦煤资源绿色开发全国重点实验室,河南平顶山467000 [2]武汉科技大学化学与化工学院,煤转化与先进炭材料湖北省中试基地,湖北武汉430080 [3]平煤股份煤炭开采利用研究院,河南平顶山467000

出　　处：《燃料化学学报(中英文)》2025年第4期589-601,共13页Journal of Fuel Chemistry and Technology

基　　金：国家自然科学基金(U1864207)资助。

摘　　要：为了探究原料沥青的脂肪侧链结构对其中间相转化过程及针状焦微观结构的影响,本研究以具有不同脂肪侧链结构的石油沥青(PP)、煤沥青(CTP)和乙烯焦油沥青(ETP)为原料通过中间相转化、焦化、煅烧和石墨化过程分别制备石墨化焦(GNC),并考察了三者作为锂电负极的电化学性能。结果表明,PP中丰富CH_(3)短烷基侧链能有效降低分子间的CH-π相互作用,促进芳香分子的排列堆积取向,从而降低其石墨化难度;ETP中的烯烃和长烷基侧链组分则降低中间相转化效率及产物的分子平面度,其针状焦石墨化难度增大,晶体发育受限;尽管CTP中的烷基侧链含量最低,但得益于分子间的强π-π键作用,使其中间相转化效率居于前两者之间。最终,石墨化焦的晶体尺寸PP-GNC>CTP-GNC>ETP-GNC,三者作为锂电负极的首次放电比容量和首次库伦效率依次降低,其循环稳定性能则有所提高。The aliphatic side groups components in raw pitches have been considered to make some significant influence on the structure and properties of the prepared needle cokes.In order to investigate the influence of the different aliphatic side groups structures of raw pitch on the mesophase transformation process and the microstructure of needle cokes,three graphitized needle cokes(GNCs)were prepared from petroleum pitch(PP),coal tar pitch(CTP)and ethylene tar pitch(ETP),especially,via mesophase transformation,coking,calcination and graphitization processes.The molecuar structures of the three feedstocks and their derived mesophase pitches were analyzed by infrared spectrometer(IR),nuclear magnetic resonance spectrometer(NMR)and time-of-flight mass spectrometry(TOF-MS),and the microsrstalline structure evolutions during preparation of GNCs as well as the electrochemical properties of the three GNCs as lithium anode were investigated.Molecular structure analysis results shown that both PP and ETP possessed abundant aliphatic side groups.However,the substitued components in PP were mainly short CH3 aliphatic groups and naphthenic structures while ETP had some longer substitued aliphatic side groups and more olefin components.Besides,CTP demeonstated the highest aromaticity degree with limitted aliphatic side groups content.Further molecular structure analysis results showed that these abundant CH_(3) aliphatic groups consisted in PP effectively reduced the CH-πinteraction of aromatic molecules and improved their stacking orientation of its masophase pitch,thus promoting its graphitization of the consequent needle coke.However,the olefin components and longer aliphatic chains of ETP reduced its mesophase transform efficiency and the molecular flatness of the mesophase pitch,then being not conducive to the crystal development during graphitization.Although containing lowest CH3 aliphatic groups,CTP exhibited moderate mesophase transform efficiency and graphite crystal structure of their needle coke due to the strongπ-π

关 键 词：中间相沥青 针状焦 分子结构 延迟焦化 微观结构 

分 类 号：TQ523.4[化学工程—煤化学工程]