摘要
Carbon nanofibers with a polygonal cross section （P-CNFs） synthesized using a catalytic chemical vapor deposition （CCVD） technology have been investigated for potential applications in lithium batteries as anode materials. P-CNFs exhibit excellent high-rate capabilities. At a current density as high as 3.7 and 7.4 A/g, P-CNFs can still deliver a reversible capacity of 198.4 and 158.2 mAh/g, respectively. To improve their first coulombic efficiency, carbon-coated P-CNFs were prepared through thermal vapor deposition （TVD） of benzene at 900 ~C. The electrochemical results demonstrate that appropriate amount of carbon coating can improve the first coulombic efficiency, the cycling stability and the rate performance of P-CNFs. After carbon coating, P-CNFs gain a weight increase approximately by 103 wt%, with its first coulombic efficiency increasing from 63.1 to 78.4%, and deliver a reversible capacity of 197.4mAh/g at a current density of 3.7 A/g, After dozens of cycles, there is no significant capacity degradation at both low and high current densities.
Carbon nanofibers with a polygonal cross section （P-CNFs） synthesized using a catalytic chemical vapor deposition （CCVD） technology have been investigated for potential applications in lithium batteries as anode materials. P-CNFs exhibit excellent high-rate capabilities. At a current density as high as 3.7 and 7.4 A/g, P-CNFs can still deliver a reversible capacity of 198.4 and 158.2 mAh/g, respectively. To improve their first coulombic efficiency, carbon-coated P-CNFs were prepared through thermal vapor deposition （TVD） of benzene at 900 ~C. The electrochemical results demonstrate that appropriate amount of carbon coating can improve the first coulombic efficiency, the cycling stability and the rate performance of P-CNFs. After carbon coating, P-CNFs gain a weight increase approximately by 103 wt%, with its first coulombic efficiency increasing from 63.1 to 78.4%, and deliver a reversible capacity of 197.4mAh/g at a current density of 3.7 A/g, After dozens of cycles, there is no significant capacity degradation at both low and high current densities.
基金
financial support from the Ministry of Science and Technology of China(2011CB932604)
