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 m...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.展开更多
基金financial support from the Ministry of Science and Technology of China(2011CB932604)
文摘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.
