SUPPLEMENTARY INFORMATION Engineering of Hollow Core-Shell Interlinked Carbon Spheres for Highly Stable Lithium-Sulfur Batteries Qiang Sun, Bin He, Xiang-Qian Zhang, and An-Hui Lu* State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, P. R. China E-mail: anhuilu@dlut.edu.cn, Tel/Fax: +86-411-84986112 1
Table of contents Section I. Supporting Figures Figure S1. TEM image of SCS. Figure S2. HRSEM image of CSC. Figure S3. Nitrogen sorption isotherm of SCS. Figure S4. Profiles of four kinds of drupes. (Drupe: a fleshy indehiscent fruit containing an anchored seed) Figure S5. TEM images of CSC with the sample holder tilted to -40 o, 0 o and 40 o by rotation around the axis of the holder. Figure S6. TEM images of CSC@SiO 2 with the sample holder tilted to a) 0 o, b) -25 o away from the direction perpendicular of the holder, and c) +40 o by rotation around the axis of the holder; d) The magnified TEM image of the marked position of c). Figure S7. SEM image and energy-dispersive X-ray (EDX) elemental mapping of CSC-S-70. Figure S8. TEM image of CSC-S-70. Figure S9. TGA curve of CSC-S-85 in an argon flow. Figure S10. a) Cycling performances of CSC-S-85 at a current density of 0.4 C and 3.2 C (1 C=1675 ma g -1 ); b) rate capacities of CSC-S-85. Figure S11. TEM image of the CSC-S-70 after 200 cycles. The small particles in the yellow dashed box are conductive carbons which were added during the preparation of the electrode. Section II. Supporting Table Table S1. The comparsion of capacity for the CSC-S cathode in this paper and other sulfur cathodes reported in the literature. 2
Section I. Supporting Figures Figure S1. TEM image of SCS. Figure S2. HRSEM image of CSC. 3
Figure S3. Nitrogen sorption isotherm of SCS. Figure S4. Profiles of four kinds of drupes. (Drupe: a fleshy indehiscent fruit containing an anchored seed) 4
Figure S5. TEM images of CSC with the sample holder tilted to -40 o, 0 o and 40 o by rotation around the axis of the holder. Figure S6. TEM images of CSC@SiO 2 with the sample holder tilted to a) 0 o, b) -25 o away from the direction perpendicular of the holder, and c) +40 o by rotation around the axis of the holder; d) The magnified TEM image of the marked position of c). 5
Figure S7. SEM image and energy-dispersive X-ray (EDX) elemental mapping of CSC-S-70. Figure S8. TEM image of CSC-S-70 6
Figure S9. TGA curve of CSC-S-85 in an argon flow. Figure S10. a) Cycling performances of CSC-S-85 at a current density of 0.4 C and 3.2 C (1 C=1675 ma g-1); b) rate capacities of CSC-S-85. 7
Figure S11. TEM image of the CSC-S-70 after 200 cycles. The small particles in the yellow dashed box are conductive carbons which were added during the preparation of the electrode. Section II. Supporting Tables Table S1. The comparison of capacity for the CSC-S cathode in this paper and other sulfur cathodes reported in the literature. Carbon host Sulfur Electrochemical performances Ref. content C-rate/cycles Capacity (ma h g -1 ) High C-rate /cycles Capacity (ma h g -1 ) Hollow core-shell nanocarbons 70% 0.5 C/200 960 4.0 C/200 730 This study Hollow carbon 65% 0.2 C/100 900 0.6 C/600 630 1 Core-shell carbon 65.3% 0.5 C/200 665 4.0 C/200 343.8 2 Carbon nanospheres 42% 0.24 C/500 650 0.72C/20 730 3 Carbon coating on CNT 40.2% 0.1 C/200 1142 5.0 C/10 800 4 Mesoporous carbon 50% 0.1 C/100 840 1.0 C/50 750 5 Hollow carbon spheres 50.2% 0.05 C/50 1357 0.5 C/50 784 6 CMK-3 70% 0.1 C/20 1100 NG NG 7 Mesopoeous carbon sphere 50% NG NG 1.0 C/100 730 8 Mesoporous carbon 50% 1.0 C/100 602 2.0 C/100 501 9 Hierarchically ordered 50% 0.1 C/50 884 2.0 C/10 458 10 porous carbon Hollow carbon spheres 64% 0.1 C/100 690 1.0 C/5 350 11 Hollow carbon spheres 72% 0.2 C/100 980 2.0 C/10 350 12 8
REFERENCES 1. Zhou, W.; Xiao, X.; Cai, M.; Yang, L. Polydopamine-Coated, Nitrogen-Doped, Hollow Carbon-Sulfur Double-Layered Core Shell Structure for Improving Lithium-Sulfur Batteries. Nano Lett. 2014, 14, 5250-5256. 2. Zhang, F.-F.; Huang, G.; Wang, X.-X.; Qin, Y.-L.; Du, X.-C.; Yin, D.-M.; Liang, F.; Wang, L.-M. Sulfur-Impregnated Core-Shell Hierarchical Porous Carbon for Lithium-Sulfur Batteries. Chem. Eur. J. 2014, 20, 17523-17529. 3. Zhang, B.; Qin, X.; Li, G. R.; Gao, X. P. Enhancement of Long Stability of Sulfur Cathode by Encapsulating Sulfur into Micropores of Carbon Spheres. Energy Environ. Sci. 2010, 3, 1531-1537. 4. Xin, S.; Gu, L.; Zhao, N.-H.; Yin, Y.-X.; Zhou, L.-J.; Guo, Y.-G.; Wan, L.-J. Smaller Sulfur Molecules Promise Better Lithium-Sulfur Batteries. J. Am. Chem. Soc. 2012, 134, 18510-18513. 5. Li, X.; Cao, Y.; Qi, W.; Saraf, L. V.; Xiao, J.; Nie, Z.; Mietek, J.; Zhang, J.-G.; Schwenzera, B.; Liu, J. Optimization of Mesoporous Carbon Structures for Lithium-Sulfur Battery Applications. J. Mater. Chem. 2011, 21, 16603-16610. 6. Zhang, K.; Zhao, Q.; Tao, Z.; Chen, J. Composite of Sulfur Impregnated in Porous Hollow Carbon Spheres as the Cathode of Li-S Batteries with High Performance. Nano Res. 2013, 6, 38-46. 7. Ji, X.; Lee, K. T.; Nazar, L. F. A Highly Ordered Nanostructured Carbon Sulphur Cathode for Lithium-Sulphur Batteries. Nat. Mater. 2009, 8, 500-506. 9
8. Schuster, J.; He, G.; Mandlmeier, B.; Yim, T.; Lee, K. T.; Bein, T.; Nazar, L. F. Spherical Ordered Mesoporous Carbon Nanoparticles with High Porosity for Lithium-Sulfur Batteries. Angew. Chem. Int. Ed. 2012, 51, 3591-3595. 9. He, G.; Ji, X.; Nazar, L. F. High C Rate Li-S Cathodes: Sulfur Imbibed Bimodal Porous Carbons. Energy Environ. Sci. 2011, 4, 2878-2883. 10. Ding, B.; Yuan, C.; Shen, L.; Xu, G.; Nie, P.; Zhang, X. Encapsulating Sulfur into Hierarchically Ordered Porous Carbon as A High-Performance Cathode for Lithium-Sulfur Batteries. Chem. Eur. J. 2013, 19, 1013-1019. 11. Zhang, C.; Wu, H. B.; Yuan, C.; Guo, Z.; Lou, X. W. Confining Sulfur in Double-Shelled Hollow Carbon Spheres for Lithium-Sulfur Batteries. Angew. Chem. Int. Ed. 2012, 51, 9592-9597. 12. Zhou, W.; Wang, C.; Zhang, Q.; Abruña, H. D.; He, Y.; Wang, J.; Mao, S. X.; Xiao, X. Tailoring Pore Size of Nitrogen-Doped Hollow Carbon Nanospheres for Confining Sulfur in Lithium-Sulfur Batteries. Adv. Energy Mater. 2015, 1401752. 10