Characteristics of Electrochemical Insertion Lithium of Carbon Nanotubes
- Received Date: 2000-05-21
- Carbon nanotubes, Lithium ion rechargeable battery, Negative materials, Electrochemical storage lithium /
Abstract: The microstructure of the carbon nanotubes were characterized by means of transmis-sion electron microscope, high-resolution transmission electron microscope, X-ray diffraction and Raman spectra. The effects of the microstructure on their properties of electrochemical insertion were investigated. The carbon nanotube, which preparaed by catalytic decomposition of acetylene using iron nanoparticles as catalyst, showed a low degree of graphitization. There were large amount of the defects such as wrinkled graphite sheets, interstitial carbon atoms, unorga-nized graphitic structure and microcavities in this nanotube and lead to a higher specific capacity, which is 640mAh/g at first cycle. But the defect structure resulted in a low cycling stability. After 40 cycles, its capacity was degraded to 58% of the original one. The carbon nanotube, which prepared by the pyrolysis of ethylene catalyzed by iron oxide nanoparticales, showed a high degree of graphitization and a rule microstructure. The well-graphitized carbon nanotube exhibited a low electrochemical storage lithium capacity, which is 282mAh/g at first cycle. But it showed a good cycling stability. After 40 cycles, the capacity maintained 86% of the original capacity. The influences of the temperature and charge/discharge current densities on their electrochemical storage lithium capacities were also discussed.
|Citation:||Chen Weixianga, Wu Guotaob, Wang Chunshengc, Yang Hangshenga, He Peimob, Zhang Xiaobinc, Xu Zhudea, Li Wenzhub, Yang Yong. Characteristics of Electrochemical Insertion Lithium of Carbon Nanotubes[J]. Chinese Journal of Chemical Physics , 2001, 14(1): 88-94. doi: 10.1088/1674-0068/14/1/88-94|