Supporting Information Tuning the Shell Number of Multi-Shelled Metal Oxide Hollow Fibers for Optimized Lithium Ion Storage Jin Sun, Chunxiao Lv, Fan Lv, ǁ Shuai Chen, Daohao Li, Ziqi Guo, Wei Han, Dongjiang Yang, *,, # and Shaojun Guo *,ǁ Collaborative Innovation Center for Marine Biomass Fibers Materials and Textiles of Shandong Province, School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, P. R. China. Department of Materials Science and Engineering, and BIC-ESAT, College of Engineering, Peking University, Beijing 100871, P. R. China. State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Science, Taiyuan 030001, P. R. China. College of Science, China University of Petroleum, Qingdao 266580, P. R. China. Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University, Changchun 130012, P. R. China. # Key Laboratory of Coal Science and Technology, Taiyuan University of Technology, Ministry of Education and Shanxi Province, Taiyuan 030024, P. R. China. Email: d.yang@qdu.edu.cn (Dongjiang Yang*); guosj@pku.edu.cn (Shaojun Guo*)
Figure S1. Photographs of Ni-AF with the increased volume fraction of ethanol from 0 % to 66 %.
Figure S2. XRD patterns of multi-shelled NiO hollow microfibers.
Figure S3. Low-magnification SEM images of (a) single-shelled, (b) double-shelled, and (c) triple-shelled and (d) shell-broken NiO hollow microfibers.
Figure S4. XRD patterns of multi-shelled Co 3 O 4 hollow microfibers.
Figure S5. XRD patterns of multi-shelled Fe 2 O 3 hollow microfibers.
Figure S6. Low-magnification SEM images of (a) single-shelled, (b) double-shelled, and (c) triple-shelled and (d) shell-broken Co 3 O 4 hollow microfibers.
Figure S7. Low-magnification SEM images of (a) single-shelled, (b) double-shelled, and (c) triple-shelled and (d) shell-broken Fe2O3 hollow microfibers.
Figure S8. (a) Cyclic voltammograms of triple-shelled Co 3 O 4 hollow microfibers at different sweep rates. The inset shows the corresponding the relationship of the sweep rate and peak current. (b) The Nyquist plots of multi-shelled Co 3 O 4 hollow microfibers. Figure S9. (a) Cyclic voltammograms of triple-shelled Fe 2 O 3 hollow microfibers at different sweep rates. The inset shows the corresponding the relationship of the sweep rate and peak current. (b) The Nyquist plots of multi-shelled Fe 2 O 3 hollow microfibers.
Table S1. Summary of synthesis conditions of various multi-shelled NiO/Co 3 O 4 /Fe 2 O 3 hollow microfibers. Ni(Ac) 2 4H 2 O Structures Co(Ac) 2 4H 2 O, FeCl 3 6H 2 O, Water: Ethanol (v:v) Calcination temperature Concentration (M) Single-shelled 0.1 1:0 500 C Double-shelled 0.1 2:1 500 C Triple-shelled 0.1 1:1 500 C Shell-broken 0.1 1:2 500 C
Table S2. Comparisons of the LIBs performance of triple-shelled Co 3 O 4 /Fe 2 O 3 hollow microfibres and recently reported Fe 2 O 3 /NiO-based materials. Current Reversible Cycle Sample density (ma capacity number References g 1 ) (mah g 1 ) (Times) Double-shelled hollow Co 3 O 4 spheres 178 866 50 Adv. Funct. Mater. 2010, 20, 1680 1 Hierarchical CNT/ Co 3 O 4 microtubes 1000 782 200 Angew. Chem. Int. Ed. 2016, 55, 5990 2 Peapod-like Co 3 O 4 @carbon nanotube 100 700 60 Angew. Chem. Int. Ed. 2015, 54, 7060 3 Co 3 O 4 CNT heterostructures 375 758 30 Nanoscale, 2013, 5, 8067 4 Hollow Co 3 O 4 parallelepipeds 100 1100 50 J. Mater. Chem. A, 2015, 3, 22542 5 Mesoporous nanostructured Co 3 O 4 200 913 60 J. Mater. Chem. A, 2015, 3, 5585 6 H 2 @Co 3 O 4 nanofiber 100 916 100 Sci. Rep. 2015, 5, 12382 7
Triple-shelled Co 3 O 4 microfibre 1000 940 200 This work Fe 2 O 3 yolk shell 300 848 80 Nanoscale, 2013, 5, 11592 8 a-fe 2 O 3 multi-shelled hollow spheres 400 1000 50 Chem. Commun., 2013, 49, 8695 9 1D hollow α-fe 2 O 3 electrospun nanofibers 60 1293 40 J. Mater. Chem., 2012, 22, 23049 10 Carbon coated CNT@ Fe 2 O 3 500 820 100 Energy Environ. Sci. 2012, 5, 5252 11 α- Fe 2 O 3 Hollow Spheres 200 710 100 J. Am. Chem. Soc. 2011, 133, 17146 12 Thin and thick α-fe 2 O 3 multi-shelled hollow spheres 50 1702 50 Energy Environ. Sci., 2014, 7, 632 13 Bubble-nanorod-structured Fe 2 O 3 -C composite nanofibers 1000 812 300 ACS Nano, 2015,9 4026 14 Triple-shelled Fe 2 O 3 microfibres 1000 1080 200 This work
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