首页|由乙烯焦油制备锂离子电池负极材料用碳质前驱体的氧化反应机理与反应动力学

由乙烯焦油制备锂离子电池负极材料用碳质前驱体的氧化反应机理与反应动力学

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  • 国家科技期刊平台
  • NETL
  • NSTL
  • 万方数据
为了得到优质的碳质前驱体,研究了乙烯焦油在空气中的氧化反应机理及其反应动力学,并制备出高软化点沥青应用于锂离子电池负极石墨材料的包覆改性.根据热重曲线将乙烯焦油的氧化过程分成350-550、550-700和700-900 K三个阶段,并采用质谱和红外技术对不同反应温度下的尾气成份进行在线分析以揭示乙烯焦油在空气中的氧化反应机理.根据不同反应温度下乙烯焦油与氧气的热失重曲线,整个反应过程被分为4个阶段,进一步利用Coats-Red-fern 等转化率法分析 17种常用反应动力学模型与实验数据的拟合度,筛选出最适宜表达乙烯焦油与氧气的反应动力学模型.结果表明:(1)在乙烯焦油的氧化过程中,芳香化合物的支链先与氧气反应生成醇类、醛类小分子化合物和含有过氧自由基的芳香化合物,然后含有过氧自由基的芳香化合物进行热缩聚反应形成分子量更大的芳香族化合物;(2)可采用四级反应模型描述乙烯焦油的前3阶段反应动力学,活化能分别为47.33、18.69和9.00kJ·mol-1;可采用三维扩散模型描述第4阶段的反应动力学,其活化能为88.37 kJ·mol-1.(3)经所制沥青包覆改性后,石墨负极循环300圈后的容量保持率由 51.54％增长为 79.07％.
The oxidation reaction mechanism and its kinetics for a carbonaceous precursor prepared from ethylene tar for use as an anode material for lithium-ion batteries
The oxidation reaction mechanism and its kinetics for ethylene tar were investigated in order to obtain a suitable anode material for Li-ion batteries.The oxidation of ethylene tar was divided into 3 stages(350-550,550-700 and 700-900 K)according to the thermogravimetric curve.To reveal the oxidation reaction mechanism,the components of the gases evolved at different stages were analyzed by mass spectrometry and infrared technology.Based on these results the reaction was divided into 4 stages(323-400,400-605,605-750 and 750-860 K)to perform simulation calculations of the kinetics.Using the iso-conversion method(Coats-Red-fern)to analyze the linear regression rates(R2)between 17 common reaction kinetics models and experimental data,an optimum re-action kinetics model for expressing the oxidation of ethylene tar was determined and the results were as follows.(1)During oxida-tion,the side chains of aromatic compounds first react with oxygen to form alcohols and aldehydes,leaving peroxy-radicals on aro-matic rings.Subsequently,the aromatic compounds with peroxy-radicals undergo polymerization/condensation reactions to form lar-ger molecules.(2)A fourth-order reaction model was used to describe the first 3 stages in the oxidation process,and the activation energies are 47.33,18.69 and 9.00 kJ·mol-1 at 323-400,400-605,605-750 K,respectively.A three-dimensional diffusion model was applied to the fourth stage of the oxidation process,and the activation energy is 88.37 kJ·mol-1 at 750-860 K.A high softening point pitch was also produced for use as a coating of the graphite anode,and after it had been applied the capacity retention after 300 cycles increased from 51.54％to 79.07％.

Ethylene tarOxidation reaction mechanismReaction kineticsCarbonaceous precursorLithium-ion batteries

郭天瑞、陈荣起、高伟、王艳莉、詹亮

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华东理工大学化学工程联合国家重点实验室,上海 200237

乙烯焦油 氧化反应机理 反应动力学 碳质前驱体 锂离子电池

国家自然科学基金国家自然科学基金国家自然科学基金国家自然科学基金国家自然科学基金国家自然科学基金国家自然科学基金

5147208651002051U171025250730003506720252080602422075081

2024

10.1016/S1872-5805(22)60597-3

新型炭材料
中国科学院山西煤炭化学研究所

新型炭材料

CSTPCD北大核心
影响因子：0.685
ISSN：1007-8827
年,卷(期)：2024.39(2)
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