摘要
以石油沥青为原料,采用悬浮加热法分别制备了颗粒状和球状硬炭。采用X射线衍射分析、扫描电子显微镜以及CO_2吸附测试对材料结构进行表征;利用恒流充放电和电化学阻抗谱技术对电化学性能进行了测试。结果表明,随着炭化温度从1 000℃升高到1 400℃,球状硬炭材料的CO_2吸附比表面积、孔容和充放电比容量逐渐减小,而首次库仑效率逐渐升高。在电流密度为37.2 mA/g下循环100次后球状硬炭的体积容量比颗粒状硬炭高出17.7%,且球形硬炭的电阻更小,在电流密度为1 860 mA/g时的比容量为103.3 mAh/g。
The particulate and spherical hard carbons were prepared by heating petroleum pitch precursors in suspension liquid. The morphology and structure of hard carbon were characterized by X-ray diffraction, scanning electron microscope and CO_2 adsorption measurements. The electrochemical performance was tested by constant charge-discharge and electrochemical impedance spectroscopy. The results show that as the heat-treatment temperature increases from 1 000 ℃ to 1 400 ℃, the CO_2 adsorption specific surface area, pore volume and charge-discharge capacity of the spherical hard carbon material gradually decrease, while the first columbic efficiency gradually increases. The volume capacity of the spherical hard carbon material is 17.7% higher than the particulate one after 100 cycles at the current density of 37.2 mA/g, the resistance of the spherical hard carbon is smaller, and the specific capacity of the spherical hard carbon is 103.3 mAh/g at the current density of 1 860 mA/g.
出处
《电源技术》
CAS
CSCD
北大核心
2018年第2期172-174,222,共4页
Chinese Journal of Power Sources
基金
国家自然科学基金资助项目(21177038)
关键词
球形硬炭
负极
锂离子电池
电化学性能
spherical hard carbon
anode
lithium ion battery
electrochemical performance
