CaC2-CCl4体系反应制备纳米碳球及其电化学性能

PREPARATION AND ELECTROCHEMICAL PROPERTIES OF CARBON NANOSPHERES FROM CaC_2-CCl_4 SYSTEM

以碳化钙和四氯化碳为碳源,反应物通过无机化学反应在密封高压釜中制备了纳米碳球。用XRD、SEM、EDS、TEM、HRTEM和BET法对碳球的形貌和结构进行表征,并采用恒流放电法研究其作为锂离子电池负极材料的电化学性能。研究结果表明:合成的纳米碳球具有棉花状结构,直径分布为80～250nm,其d002为0.336～0.340nm,属于无定形碳结构,BET比表面积为98m2/g。纳米碳球作为负极材料首次充放电比容量分别为787mA·h/g和390mA·h/g,充放电效率为49.6%;5次循环后放电比容量衰减到239mA·h/g,但效率均保持在95%以上。

Carbon nanospheres were synthesized by an inorganic chemical reaction with calcium carbide and chloroform as carbon sources in a sealed autoclave. The morphology and microstructure of the carbon spheres were characterized by XRD, SEM,EDS, TEM, HRTEM, and BET specific surface area, and the electrochemical properties of the carbon spheres as anode material for lithium- ion batteries were investigated by use of chronopotentiometry （CP） . The results indicate that the carbon spheres are composed of the cottonstructure spheres with the diameter between 80 nm and 250 nm. The d002 of the carbon spheres are in the range of 0. 336 ～0. 340 nm and the BET area surface is 98 m2/g. The first charge/discharge specific capacities of the carbon spheres as negative electrodes are 787 mA·h/g and 390 mA· h/g, respectively, and the first efficiency is 49. 5%. After 5 times cycles,the discharge specific capacity decreases to 239 mA· h/g,but the efficiency keeps above 95%.