3D Nanofibrous Air Electrode Assembled With Carbon Nanotubes Bridged Hollow Fe 2 O 3 Nanoparticles for High Performance Lithium- Oxygen Batteries

Transcription

1 Supporting Information 3D Nanofibrous Air Electrode Assembled With Carbon Nanotubes Bridged Hollow Fe 2 O 3 Nanoparticles for High Performance Lithium- Oxygen Batteries Ji-Won Jung,,a Ji-Soo Jang,,a Tae Gwang Yun, a Ki Ro Yoon a and Il-Doo Kim*,a a Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea * idkim@kaist.ac.kr J. W. Jung and J.-S. Jang contributed equally to this work. S-1

2 Table of contents Figure S1. TEM and HR-TEM images of Fe 3 C/CNT-CNFs... S-3 Figure S2. SEM and TEM images of Fe 2 O 3 /CNT NFs... S-4 Figure S3. Size distribution of hollow Fe 2 O 3 NPs in H-Fe 2 O 3 /CNT NFs... S-5 Figure S4. N 2 adsorption and desorption and pore size distribution of Fe 3 C/CNT-CNFs and H-Fe 2 O 3 /CNT NFs... S-6 Figure S5. TGA data of Fe 3 C/CNT-CNFs... S-7 Figure S6. Raman data of Fe 3 C/CNT-CNFs... S-8 Figure S7. XPS data of Fe 3 C/CNT-CNFs for Fe 2p... S-9 Figure S8. Morphologies of Li 2 O 2 grown on H-Fe 2 O 3 /CNT NFs... S-10 Figure S9. Voltage profiles and terminal voltages of KB electrode... S-11 Figure S10. I-V characteristics of H-Fe 2 O 3 /CNT NFs and Fe 2 O 3 NFs... S-12 Figure S11. TEM and HR-TEM images of H-Fe 2 O 3 /CNT NFs after first discharge.. S-13 Figure S12. XPS data of KB electrode after first discharge and recharge... S-14 Figure S13. Ex-situ XPS data of H-Fe 2 O 3 /CNT NFs... S-15 Figure S14. Digital images of Swagelok and pouch cells... S-16 Figure S15. SEM images of carbon cloth without and with H-Fe 2 O 3 /CNT NFs and KB.S-17 Table S1. Comparison for Li-O 2 cell performance of Fe-based carbon composite catalysts in air electrodes.... S-18 S-2

3 Figure S1. (a) TEM and (b) HR-TEM images of Fe3C/CNT-CNFs. S-3

4 Figure S2. (a,b) SEM images and (c-f) TEM images of H-Fe2O3/CNT NFs. S-4

5 Figure S3. Size distribution of hollow Fe 2 O 3 NPs in H-Fe 2 O 3 /CNT NFs. S-5

6 Figure S4. N 2 adsorption and desorption isotherms of (a) Fe 3 C/CNT-CNFs and (b) H- Fe 2 O 3 /CNT NFs. Pore size distribution of (c) Fe 3 C/CNT-CNFs and (d) H-Fe 2 O 3 /CNT NFs. S-6

7 Figure S5. TGA data of Fe 3 C/CNT-CNFs; this result was obtained from the sample treated in air atmosphere. S-7

8 D band G band Intensity (a. u.) (200~600 cm -1 ) Fe 3 C 2D D+G Raman shift (cm -1 ) Figure S6. Raman data of Fe 3 C/CNT-CNFs, confirming Fe 3 C and carbon phase in the composite NFs. S-8

9 Fe 2p Fe 2+ 2p 1/2 Fe metal Fe metal Intensity (a.u.) Fe 3+ 2p 1/2 Fe 3+ 2p 3/2 Fe 2+ 2p 3/ Binding energy (ev) Figure S7. XPS data of Fe 3 C/CNT-CNFs for Fe 2p. S-9

10 Figure S8. Morphological evolution of gradually growing Li2O2 on the surface of HFe2O3/CNT NFs with restricted capacities of (a) 500, (b) 1000, (c) 3000 and (d) 5000 mah g1. S-10

11 Figure S9. (a) Voltage profile and (b) terminal voltages of the LOB cell with reference KB electrode for ORR and OER; the cell was tested with a fixed capacity of 1000 mah g -1 at a current density of 500 ma g -1. S-11

12 Figure S10. I-V characteristics of H-Fe 2 O 3 /CNT NFs and Fe 2 O 3 NFs S-12

13 Figure S11. (a) TEM and (b) HR-TEM images of H-Fe 2 O 3 /CNT NFs after first discharge. S-13

14 Figure S12. XPS data of KB electrodes after (a,b) first discharge and (c,d) first recharge. S-14

15 Figure S13. Ex-situ XPS data of H-Fe 2 O 3 /CNT NFs after (a) 1st recharge and (b) 50th recharge. S-15

16 Figure S14. Digital image of small-sized electrode and large-sized electrode for Swagelok and pouch-type cells, respectively. S-16

17 Figure S15. SEM images of carbon clothes (a) without and (b) with H-Fe2O3/CNT NFs and KB, respectively. S-17

18 Table S1. Comparison for Li-O 2 cell performance of Fe-based carbon composite catalysts in air electrodes. Ref. Fe-based Air electrodes Electrolyte Limited density Charge-discharge polarization (vs. Li) (measured capacity) Cycle No. [1] Fe 2 O 3 NPs decorated CNTs 1 M LiCF 3 SO 3 in TEGDME 1500 mah g ma cm -2 ~2.0 V 40 cycles [2] XC-72 Carbon supported Fe 2 O 3 NPs 1 M LiTFSI in TEGDME 500 mah g ma g -1 ~2.0 V 50 cycles [3] Fe 2 O 3 /graphene composite LiCF 3 SO 3 :TEGD ME in molar ratio of 1:4 500 mah g ma cm -2 ~1.4 V 25 cycles [4] Hollow Fe 3 O 4 granules/c composite 1 M LiNO 3 in DMAc 1000 mah g ma g -1 ~2.25 V 81 cycles [5] Fe 3 O 4 -Fe/C nanohybrid 1 M LiNO 3 in DMAc 1000 mah g -1 ma g -1 c ~2.1 V 150 cycles [6] Heme biomolecular redox medeator/cnts 2.3 mm of hemin in 1 M LiClO 4 + TEGDME 600 mah g -1 ma g -1 c ~2.0 V 20 cycles This work H-Fe 2 O 3 /CNT NFs 1 M LiTFSI in TEGDME 1000 mah g -1 ma g -1 c ~1.25 V 250 cycles S-18

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