论文部分内容阅读
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 and7.4 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℃.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 197.4 mAh/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 could 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 virtually by 103 wt%, with its first coulombic efficiency increasing from 63.1 to 78.4%, and deliver a reversible capacity of 197.4 mAh / g at a current density of 3.7 A / g. After dozens of cycles, there is no significant capacity d egradation at both low and high current densities.