%0 Journal Article
%T 3D Hollow Sn@Carbon-Graphene Hybrid Material as Promising Anode for Lithium-Ion Batteries
%A Xiaoyu Zheng
%A Wei Lv
%A Yan-Bing He
%A Chen Zhang
%A Wei Wei
%A Ying Tao
%A Baohua Li
%A Quan-Hong Yang
%J Journal of Nanomaterials
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/974285
%X A 3D hollow Sn@C-graphene hybrid material (HSCG) with high capacity and excellent cyclic and rate performance is fabricated by a one-pot assembly method. Due to the fast electron and ion transfer as well as the efficient carbon buffer structure, the hybrid material is promising in high-performance lithium-ion battery. 1. Introduction Metallic Sn has long been considered as a promising anode material for lithium-ion batteries (LIBs) due to its high theoretical specific capacity [1, 2]. However, Sn is plagued with a rapid capacity fading because of volume expansion induced pulverization during the lithiation and delithiation reactions, leading to the breakdown of electrical connection of anode particles [3, 4]. Generally, reducing the particle size to nanoscale is an effective way to minimize the volume change [5, 6]. In order to further decrease the volume change of Sn in the electrochemical reactions, hollow Sn nanospheres (NSs), whose tensile stress is ~5 times lower than that of Sn solid NSs with an equal volume, are proven to be a better choice in electrochemical reactions [7¨C10]. Besides aforementioned routes, many researches also indicate that dispersing Sn NSs into carbon matrix is another effective approach to improve and stabilize the cyclability, where the carbon matrix restricts the volume expansion of Sn and moreover acts as an electron conductor to increase the conductivity [11¨C14]. A Sn core/carbon shell nanostructure is a typical structure to combine the advantages of carbon and Sn from above consideration, in which the carbon coating layers not only enhance the conductivity of electrode and buffer the volume variation but also help form a stable solid electrolyte interface (SEI) film. Aggregation, which hinders the fast Li+ transportation, is another problem for nanomaterials in real applications. Many latest results have shown that graphene nanosheets (GNs) are ideal substrates to well disperse NSs, which can also construct a flexible network through a ˇ°plane-to-pointˇ± mode to bridge the active material particles and form effective ion and electron transfer networks [15¨C18]. Furthermore, it is expected that such soft carbon layer could endure the volume change of the metal NSs and reduce the mechanical stress within the electrode to prevent its disintegration [10, 19, 20]. Herein, we integrate the above concerns into one hybrid structure, and a three-dimensional hollow Sn@carbon-graphene hybrid structure (abbreviated as HSCG) is obtained. In such an HSCG, hollow Sn NS was encapsulated in a carbon shell to form a core-shell sphere
%U http://www.hindawi.com/journals/jnm/2014/974285/