### 石墨烯包裹Cu2+1O/Cu复合材料的制备及其储锂性能

1. a 中国矿业大学化工学院 徐州 221116;
b 中国矿业大学材料科学与工程学院 徐州 221116;
c 固体表面物理化学国家重点实验室 厦门大学化学化工学院化学系 厦门 361005
• 投稿日期:2013-03-17 发布日期:2013-07-19
• 通讯作者: 魏贤勇,E-mail:wei_xianyong@163.com;Tel.:13605215324;庄全超,E-mail:zhuangquanchao@126.com E-mail:wei_xianyong@163.com;zhuangquanchao@126.com
• 基金资助:

项目受国家自然科学基金创新研究群体科学基金(No. 51221462)、江苏省研究生培养创新工程(No. CXZZ12_0943)和江苏高校优势学科建设工程资助.

### Fabrication and Lithium-Storage Performances of Graphene-Wrapped Cu2+1O/Cu Composites

Tian Leileia,b, Wei Xianyonga, Zhuang Quanchaob, Zong Zhimina, Sun Shigangc

1. a School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou 221116;
b School of Materials Science and Engineering, China University of Mining & Technology, Xuzhou 221116;
c State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005
• Received:2013-03-17 Published:2013-07-19
• Supported by:

Project supported by the Fund from Natural Science Foundation of China for Innovative Research Group (Grant 51221462), the Jiangsu Ordinary University Graduate Innovative Research Programs (No. CXZZ12_0943) and the Priority Academic Program Development of Jiangsu Higher Education Institutions.

Materials with hybrid metal-semiconductor nanostructures, such as graphene-metal oxides and carbon nanotube-metal oxides, have been intensively exploited as electrode material for lithium ion batteries in recent years. It was found that the structures and properties of the metal-semiconductor herterojunction and the energy level structures of the semiconductor are essential for the conductance of the metal-semiconductor composite. It is thence believed that the conductance, and thus the lithium-storage performance, of the metal-semiconductor composite can be improved by tuning the structures of the metal-semiconductor herterojunction and the energy level structures of the semiconductor. Metal excess defects can occured in metal oxide crystals due to the anion are absent from their its lattice sites or the presence of an extra cations at in an interstitial sites. In the metal excess type metal oxide, the electric transport is mainly by "excess" electrons which are present for maintaining the electrical neutrality, and thus possesses a higher conductance. In this work, graphene-wrapped Cu2+1O/Cu composites were successfully fabricated by using a hydrothermal reaction followed by an in situ thermal reduction. The structures, surface morphologies and the lithium-storage performances of the obtained materials were characterized and investigated by scanning electron microscopy, X-ray diffraction and galvanostatic discharge-charge techniques. In the obtained hybrid material, highly-crystallized Cu2+1O (Cu2O with metal excess defects) successfully formed during the heat treatment processes, Cu2+1O and Cu particles were homogeneously wrapped by flexible graphene sheets with a well defined core-shell structure. Constant current charge-discharge results showed that graphene-wrapped Cu2+1O/Cu composite had a higher reversible capacity and excellent cycling stability, delivered a higher initial charge-discharge capacity of 773 and 438 mA•h•g-1 at 50 mA•g-1 and superb cycling performance of 368 mA•h•g-1 after 60 cycles, as well as a favorable rate capabilities and high rate cycling performances, indicating the high conductance and the optimized herterojunctions were achieved by the simultaneously introduction of metal excess defects, metallic copper and graphene in graphene-wrapped Cu2+1O/Cu composites.