【作者】 王邓军； 王艳莉； 詹亮； 张秀云； 刘春法； 乔文明； 凌立成；

【Author】 WANG Deng-Jun;WANG Yan-Li;ZHAN Liang;ZHANG Xiu-Yun;Liu Chun-Fa;QIAO Wen-Ming;LING Li-Cheng;State Key Laboratory of Chemical Engineering,East China University of Science and Technology;Baosteel Group Shanghai Chemical Corporation;

【机构】 华东理工大学化学工程联合国家重点实验室； 上海宝钢化工有限公司；

【摘要】 通过考察煤系针状焦在700~2800℃热处理过程中石墨微晶结构的变化规律及其电化学性能,并结合TG-DTG、XRD、SEM、XPS表征方法以及充放电、循环伏安曲线特征,分析了针状焦的石墨化机理及其储锂机制.研究结果表明,随热处理温度的升高,针状焦的类石墨微晶在不断长大的同时,还存在微晶在径/轴向的排列、石墨层间位错线的消失、晶界间C-C六圆环的形成、晶界的消失以及石墨层"褶皱"的平面化等复杂过程,且每个过程的驱动力不同.针状焦经过2800℃石墨化后,可获得较低的Li~+充放电电位和稳定的充放电平台,且反复充放电40次后的有效嵌锂容量为305mAh/g.更多还原

【Abstract】 Effects of heat-treatment temperature on the microstructure and electrochemical properties of coal based needle coke were investigated by TG-DTG,XRD,SEM,XPS analysis and the charge/discharge,cyclic voltammetry curves.The graphitization mechanism of needle coke is suggested as well as the Li~+ extraction-insertion behaviors.With the heat-treatment temperature increasing,the graphite-like crystal grows continuously attended with a complicated process,including the arrangement of crystal along radial/axial direction,dislocation dispersion among graphite layers,hexagonal carbon formation,crystal edge dispersion and folded graphite layer turning to plane.Meanwhile,the driving-forces are far different for different process.When needle coke is graphitized at 2800°C,it exhibits a lower charge/discharge potential and stable charge/discharge platform,and the insertion capacitance of Li~+ can maintain at 305mAh/g even after charge/discharged for 40 cycles.更多还原