主题:    Electrospun Nanostructured Composite Fiber Anodes for  Li-ion Batteries主讲人:   周利民 地点:   松江校区1342教室时间:   2015-09-25 10:00:00组织单位:   材料学院

周利民教授主要研究包括：先进工程材料与结构的制造，表征和力学特征，包括纤维增强高分子基复合材料，智能材料与结构，纳米材料及技术，基于納米材料与结构的锂电池材料，及基于超声导波的结构健康监测技术。他在以上领域发表文章300余篇，包括200 余篇SCI国际期刊论文，并撰写了所从事研究领域的参考书籍的部分章节。周利民教授目前是中国复合材料学会副理事长，香港研究资助局工程学学科专家组成员。

内容摘要：Considerable attention has been paid to  rechargeable lithium ion batteries (LIBs) because of their high energy density  and long cycle lifetime. However, exploring and developing novel electrode  materials with sufficiently high energy and power density to meet the  requirements imposed on application of LIBs in high-power devices such as  electric vehicles (EV) and hybrid electric vehicles (HEV) remains a challenge.  In this study, we have successfully prepared amorphous carbon nanofibers and  carbon nanotubes decorated with hollow graphitic carbon nanospheres by  electrospinning method. A hollow-tunnel structure in electrospun carbon/Ni  nanofibres was also produced  by diffusing Ni nanoparticles from the graphitic  carbon spheres into amorphous carbon nanofibres, which turns amorphous carbon  into graphitic carbon. The resultant materials were further treated by chemical  activation and acid treatment to develop activated N-doped hollow-tunneled  graphitic carbon nanofibers (ANHTGCNs). In a typical application, we  demonstrated that the prepared ANHTGCNs are excellent anode materials for LIBs,  displaying a super high reversible specific capacity of over ~1560 mAh g-1 and a  remarkable volumetric capacity of ~1.8 Ah cm-3 at a current density of 0.1 A g-1  with outstanding rate capability and good cycling stability. The other material  is a novel porous TiO2-carbon (TiO2-C) composite nanofibers in which Sn nanoparticles is encapsulated. In situ  TEM was used to study the structural changes and charging/discharging processes  of TiO2-C-Sn composite nanofibers. It was found that the porous TiO2-C can  accommodate volumetric change of Sn nanoparticles. As an anode, this material  shows a high capacity (875 mAh/g after 50 cycles when the current density is 0.1  A/g), long cycle life (over 10000 cycles at rate of 3 A/g with maintained  capacity of 160 mAh/g), and good rate capability.