特殊结构螺旋纳米碳纤维的制备及电化学性能

Preparation and electrochemical performance of helical carbon nanofiber with special structure

以乙炔为碳源,三水合酒石酸铜为催化剂前躯体,氩气为保护气,采用化学气相沉积法(CVD)制备特殊结构的螺旋纳米碳纤维。通过扫描电镜、透射电镜观察螺旋纳米碳纤维的形貌和结构,将制备的螺旋纳米碳纤维作为锂离子电池负极材料,通过恒电流充放电和交流阻抗谱测试其电化学性能。研究表明,催化剂在管式炉内石英管中部与进气口之间制备的DNA状螺旋纳米碳纤维螺旋紧密、长度较长、结构单一,组装的电池具有最长的充放电平台,40次充放电循环后,库伦效率保持在98.5%以上,比容量在584mAh/g以上,电化学阻抗最小,导电性最好。

Acetylene was used as the source of carbon,trihydrate tartaric acid copper was used as catalyst precursor,helical carbon nanofibers with special structures were prepared by chemical vapor deposition method（CVD）under argon gas.Morphology and structure of the nanofibers were observed by SEM and TEM,and the nanofibers were used as lithiumion battery cathode material,the electrochemical behavior of sample was tested by galvanostatic charge-discharge and electrochemical impedance spectroscopy.The result showed that the nanofibers with DNA shape was prepared by CVD using catalyst between the middle part of quartz tube and the air inlet in the tube furnace,its spiral was tight,length was longer than others and structure was single.The nanofibers with DNA shape used as cathode material had the longest charge and discharge platform,after 40charge/discharge cycles,coulombic efficiency was more than 98.5%,the specific capacity was at584mAh/g or more,electrochemical impedance was minimum,conductivity was best.