Graphene-Encapsulated Mesoporous Sno2 Composites As High Performance Anodes for Lithium-Ion

Electronic Supplementary Information

Graphene-encapsulated Mesoporous SnO2 Composites as High Performance Anodes for Lithium-ion Batteries

Shuhua Jiang, Wenbo Yue, Ziqi Gao, Yu Ren, Hui Ma, Xinhua Zhao, Yunling Liu and Xiaojing Yang

Experimental section

The normal SBA-15[1] and KIT-6[2]were synthesized according to the published literature. The typical route to prepare mesoporous SnO2 is as follows: 0.3 g of tin(II) chloride dihydrate was mixed with 0.2 g of mesoporous silica and the mixture was ground for more than 20 mins. The fine mixture was then heated at 700 °C for 4 h and cooled down to room temperature. The silica template was removed in 2 M NaOH solution at 80 °C and the porous product was collected by centrifugation, washed with distilled water thrice, and dried at 40 °C.

The graphene oxides were synthesized by chemical exfoliation of natural graphite. In brief, 5 g of graphite powder (average size 20 μm, apparent density 0.05 g cm–3) and 5 g of NaNO3 were added into 230 mL of 98% H2SO4under stirring in an ice bath. 30 g of KMnO4 was slowly added to the mixture under stirring for 15 mins at below 5 °C. The mixture was then heated at 35°C for 30 mins. Subsequently, 460 mL of distilled water was slowly introduced into the above mixture, followed by stirring the mixture at 98 °C for more than 15 mins. The mixture was further diluted with 1400 mL of distilled water and the reaction was terminated by adding 25 mL of 30 % H2O2. Meanwhile, the color of the solution turned from dark brown to bright yellow. The resulting mixture was filtered and washed with 100 mL distilled water thrice to remove residual acids and salts. As-prepared GO was dispersed in water by ultrasonication for 30 mins, followed by a low-speed centrifugation to get rid of any aggregated GO nanosheets.

1. Zhao DY, Feng JL, Huo QS, Melosh N, Fredrickson GH, Chmelka BF, Stucky GD(1998) Science 279:548

2. Kleitz F, Choi SH, Ryoo R (2003)Chem Commun 2136

Fig.S1 A, N2 adsorption/desorption isotherms measured at 77 K from M-SnO2 and B, the corresponding pore size distribution. TEM images of C, M-SnO2(S) and D, M-SnO2(K) specimens, respectively

Fig.S2SEM images of A, GM-SnO2(S)-L and B, GM-SnO2(K)-L, respectively

Fig.S3HRTEM image of GM-SnO2(S), and 2-3 layer graphene sheets at the edges

Fig.S4The first and second cycle charge–discharge curves for (a) M-SnO2(S), (b) M-SnO2(K), (c) GM-SnO2(S), (d) GM-SnO2(K), (e) GM-SnO2(S)-L and (f) GM-SnO2(K)-L at 0.1 C in the voltage range 0.01–2.0 V

Fig.S5TEM images of A, M-SnO2(S) and B, GM-SnO2(S) after fifty cycles

Fig.S6Electrochemical impedance spectra of M-SnO2(S) and GM-SnO2(S)after 5 cycles.The inset: equivalent circuit

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