Silicon@Graphene-Embedded Nanofibers As High-Performance Anodes for Lithium-Ion Batteries

The growing demand for high-performance energy storage devices for applications in electric vehicles and grid-scale energy storage devices requires dramatic improvement in the energy density as well as power density. Silicon-based anodes hold promise for such high-end applications due to its high theoretical capacity and its abundant availability in earth’s crust. However, silicon anodes are well-known to exhibit problems such as electrode pulverization due to its huge volume expansion during cycling, poor cycle life and unstable solid-electrolyte interphase (SEI) layer. Much research has been focused on improving the performance of silicon anodes using novel materials design such as controlling the particle dimension (0D, 1D and 2D), particle embedded in hollow carbon spheres as well as alloying with metals. Here, we adopt the strategy of covalent attachment of silicon nanoparticles on graphene surface, which are embedded in the polymer matrix to form nanofibrous structures. Graphene sheets covalently anchoring uniform-sized silicon nanoparticles act as conducting matrix as well as buffer to accommodate volume expansion. In addition, the nanofibrous structure along with the polymer layer further suppresses pulverization of the electrode upon cycling. Detailed characterization of the prepared hybrid material and its performance as an anode in lithium ion cell will be presented.  

[References]

[1] H. Wu, G. Zheng, N. Liu, T. J. Carney, Y. Yang, Y. Cui, Nano Lett., 12 (2012) 904.

[2] S. Murugesan, J. T. Harris, B. A. Korgel, K. J. Stevenson, Chem. Mater. 24 (2012) 1306.

[3] C. K. Chan, H. Peng, G. Liu, K. McIlwrath, X. F. Zhang, R. A. Huggins, Y. Cui, Nat. Nanotechnol. 3 (2008) 31.