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 [7–10]. 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 [11–14]. 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 “plane-to-point” mode to bridge the active material particles and form effective ion and electron transfer networks [15–18]. 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
References
[1]
S. Yang, X. Feng, S. Ivanovici, and K. Müllen, “Fabrication of graphene-encapsulated oxide nanoparticles: towards high-performance anode materials for lithium storage,” Angewandte Chemie, vol. 49, no. 45, pp. 8408–8411, 2010.
[2]
B. Luo, B. Wang, X. Li, Y. Jia, M. Liang, and L. Zhi, “Graphene-confined Sn nanosheets with enhanced lithium storage capability,” Advanced Materials, vol. 24, no. 26, pp. 3538–3543, 2012.
[3]
C.-M. Park and K.-J. Jeon, “Porous structured SnSb/C nanocomposites for Li-ion battery anodes,” Chemical Communications, vol. 47, no. 7, pp. 2122–2124, 2011.
[4]
H.-C. Shin and M. L. Liu, “Three-dimensional porous copper-tin alloy electrodes for rechargeable lithium batteries,” Advanced Functional Materials, vol. 15, no. 4, pp. 582–586, 2005.
[5]
W. Lv, Y. Tao, W. Ni et al., “One-pot self-assembly of three-dimensional graphene macroassemblies with porous core and layered shell,” Journal of Materials Chemistry, vol. 21, no. 33, pp. 12352–12357, 2011.
[6]
J. Liu, S. Z. Qiao, J. S. Chen, X. W. Lou, X. Xing, and G. Q. Lu, “Yolk/shell nanoparticles: new platforms for nanoreactors, drug delivery and lithium-ion batteries,” Chemical Communications, vol. 47, no. 47, pp. 12578–12591, 2011.
[7]
Y. Yao, M. T. McDowell, I. Ryu et al., “Interconnected silicon hollow nanospheres for lithium-ion battery anodes with long cycle life,” Nano Letters, vol. 11, no. 7, pp. 2949–2954, 2011.
[8]
W.-M. Zhang, J.-S. Hu, Y.-G. Guo et al., “Tin-nanoparticles encapsulated in elastic hollow carbon spheres for high-performance anode material in lithium-ion batteries,” Advanced Materials, vol. 20, no. 6, pp. 1160–1165, 2008.
[9]
Y.-S. Lin, J.-G. Duh, and M.-H. Hung, “Shell-by-shell synthesis and applications of carbon-coated Sn hollow nanospheres in lithium-ion battery,” The Journal of Physical Chemistry C, vol. 114, no. 30, pp. 13136–13141, 2010.
[10]
S. Liang, X. Zhu, P. Lian, W. Yang, and H. Wang, “Superior cycle performance of Sn@C/graphene nanocomposite as an anode material for lithium-ion batteries,” Journal of Solid State Chemistry, vol. 184, no. 6, pp. 1400–1404, 2011.
[11]
Y. Qiu, K. Yan, and S. Yang, “Ultrafine tin nanocrystallites encapsulated in mesoporous carbon nanowires: scalable synthesis and excellent electrochemical properties for rechargeable lithium ion batteries,” Chemical Communications, vol. 46, no. 44, pp. 8359–8361, 2010.
[12]
D. Deng and J. Y. Lee, “Reversible storage of lithium in a rambutan-like tin-carbon electrode,” Angewandte Chemie, vol. 48, no. 9, pp. 1660–1663, 2009.
[13]
W. Lv, F. Sun, D.-M. Tang et al., “A sandwich structure of graphene and nickel oxide with excellent supercapacitive performance,” Journal of Materials Chemistry, vol. 21, no. 25, pp. 9014–9019, 2011.
[14]
Y. Wang, M. Wu, Z. Jiao, and J. Y. Lee, “Sn@CNT and Sn@C@CNT nanostructures for superior reversible lithium ion storage,” Chemistry of Materials, vol. 21, no. 14, pp. 3210–3215, 2009.
[15]
A. K. Geim and K. S. Novoselov, “The rise of graphene,” Nature Materials, vol. 6, no. 3, pp. 183–191, 2007.
[16]
W. Lv, D.-M. Tang, Y.-B. He et al., “Low-temperature exfoliated graphenes: vacuum-promoted exfoliation and electrochemical energy storage,” ACS Nano, vol. 3, no. 11, pp. 3730–3736, 2009.
[17]
F.-Y. Su, C. You, Y.-B. He et al., “Flexible and planar graphene conductive additives for lithium-ion batteries,” Journal of Materials Chemistry, vol. 20, no. 43, pp. 9644–9650, 2010.
[18]
F.-Y. Su, Y.-B. He, B. Li et al., “Could graphene construct an effective conducting network in a high-power lithium ion battery?” Nano Energy, vol. 1, no. 3, pp. 429–439, 2012.
[19]
G. Zhou, D.-W. Wang, F. Li et al., “Graphene-wrapped anode material with improved reversible capacity and cyclic stability for lithium ion batteries,” Chemistry of Materials, vol. 22, no. 18, pp. 5306–5313, 2010.
[20]
S. Chen, P. Chen, M. Wu, D. Pan, and Y. Wang, “Graphene supported Sn-Sb@carbon core-shell particles as a superior anode for lithium ion batteries,” Electrochemistry Communications, vol. 12, no. 10, pp. 1302–1306, 2010.
[21]
Z.-S. Wu, W. Ren, L. Wen et al., “Graphene anchored with nanoparticles as anode of lithium ion batteries with enhanced reversible capacity and cyclic performance,” ACS Nano, vol. 4, no. 6, pp. 3187–3194, 2010.
[22]
G. Wang, B. Wang, X. Wang et al., “Sn/graphene nanocomposite with 3D architecture for enhanced reversible lithium storage in lithium ion batteries,” Journal of Materials Chemistry, vol. 19, no. 44, pp. 8378–8384, 2009.
[23]
I. Stojkovi？, N. Cvjeti？anin, M. Mitri？, and S. Mentus, “Electrochemical properties of nanostructured in aqueous solution,” Electrochimica Acta, vol. 56, no. 18, pp. 6469–6473, 2011.
[24]
L. Ji, Z. Tan, T. Kuykendall et al., “Multilayer nanoassembly of Sn-nanopillar arrays sandwiched between graphene layers for high-capacity lithium storage,” Energy & Environmental Science, vol. 4, no. 9, pp. 3611–3616, 2011.
[25]
X. W. Lou, Y. Wang, C. Yuan, J. Y. Lee, and L. A. Archer, “Template-free synthesis of Sn hollow nanostructures with high lithium storage capacity,” Advanced Materials, vol. 18, no. 17, pp. 2325–2329, 2006.
[26]
F. Wang, G. Yao, M. Xu, M. Zhao, Z. Sun, and X. Song, “Large-scale synthesis of macroporous Sn with/without carbon and their application as anode materials for lithium-ion batteries,” Journal of Alloys and Compounds, vol. 509, no. 20, pp. 5969–5973, 2011.
