Title Page
Abstract
초록
Contents
Chapter 1. Introduction 17
Chapter 2. Theoretical Background 20
2-1. Zinc-air battery (ZABs) 20
2-2. ORR, OER catalytic activity 25
2-3. Effect of nanostructure architecture on ZABs characteristics 28
2-3-1. Morphological features in ZABs 29
2-3-2. Heteroatom-doped carbon effects on ZABs 32
2-3-3. Transtion metal oxide effects on ZABs 35
2-4. Synthesis methode for nitrogen-doped carbon nanotube 38
Chapter 3. Experimental 41
3-1. Preparation of 3D macroporous microsphere composed of surface areas-controlled bamboo-shaped N-doped CNT with dispersed Co3O4 nanoparticles (f-Co/BCNT_10Mg/Ni) powders 41
3-2. Characterization 44
3-3. Electrochemical Characterization 45
Chapter 4. Results & Discussion 48
4. 3D macroporous microsphere composed of surface areas-controlled bamboo-shaped N-doped CNT with dispersed Co3O4 nanoparticles (f-Co/BCNT_10Mg/Ni) as bifunctional oxygen electrocatalysts for Zn–air batteries 48
4-1. Formation mechanism 48
4-2. Phase and morphology analyses 50
4-3. Electrochemical properties 69
Chapter 5. Conclusions 85
Chapter 6. Reference 87
Table 1. Zn-air battery performances of various transition metal oxide/N-doped carbon hybrid catalysts for air cathode reported in the previous studies.
Fig. 2-1-1. Schematic illustration of a typical zinc-air battery. 21
Fig. 2-3-1. Schematic illustration of 3D honey combo-like strcture carbon materials 31
Fig. 2-3-2. Schematic illustration of hollow N-doped carbon sphere embedded with Fe-Nx/ Fe₃C.[이미지참조] 31
Fig. 2-3-3. Schematic illustration of 3D-core shell structure electrocatalysts consisted with Co nanoparticle encapsulated in S, N dual-doped carbon nanotubes. 34
Fig. 2-3-4. Schematic illustration of N,F and B ternerary doped carbon fiber. 34
Fig. 2-3-5. Schematic illustration of hollow Co₃O₄ nanosphere embedded in N-doped carbon nanowall and coated with carbon layer. 37
Fig. 2-3-6. Schematic illustration of FeCo alloy nanoparticles encapsulated by pod-shaped N-dope CNTs. 40
Fig. 2-3-7. Schematic illustration Cobalt and tungsten carbided loaded on N-doped CNTs. 40
Fig. 3-1-1. Schematic illustration of the spray pyrolysis system used to prepare the porous microspheres powder. 43
Fig. 3-1-2. Schematic illustration of 3D macroporous microsphere composed of surface areas-controlled bamboo-shaped N-doped CNT with dispersed... 43
Fig. 4-2-1. Morphologies, SAED pattern, and elemental mapping images of MgO-NiO porous microspheres: (a) SEM image, (b) TEM image, (c) HR-... 51
Fig. 4-2-2. XRD patterns of MgO-NiO, BCNT-10Mg/Ni, and f-Co/BCNT_10Mg/Ni. 52
Fig. 4-2-3. SEM images of BCNT-10Mg/Ni before MgO etching. 54
Fig. 4-2-4. Morphologies, SAED pattern, and elemental mapping images of BCNT-10Mg/Ni: (a) SEM image, (b and c) TEM images, (d) HR-TEM image,... 55
Fig. 4-2-5. SEM images of (a) BCNT-1Mg/Ni, (b) BCNT-3Mg/Ni, and (c) BCNT-5Mg/Ni. 58
Fig. 4-2-6. TEM images of various ratio of Mg and Ni for BCNT_xMg/Ni: (a and b) 1:1, (c and d) 3:1, (e and f) 5:1, and (g and h) 10:1. 59
Fig. 4-2-7. (a) N₂ gas adsorption and desorption isotherms and (b) pore-size distributions of BCNT_xMg/Ni. 60
Fig. 4-2-8. Morphologies, SAED pattern, and elemental mapping images of f-Co/BCNT_10Mg/Ni: (a) SEM image, (b and c) TEM image, (d) HR-TEM... 63
Fig. 4-2-9. SEM images of (a) the precursor and (b) b-Co₃O₄ and (c) XRD pattern of b-Co₃O₄. 64
Fig. 4-2-10. (a) N2 gas adsorption and desorption isotherm, (b) pore-size distribution, (c) TGA curve, and (d) Raman spectrum of f-Co/BCNT_10Mg/Ni. 67
Fig. 4-2-11. XPS spectra of f-Co/BCNT_10Mg/Ni: (a) Co 2p, (b) O 1 s, (c) C 1 s, and (d) N 1 s. 68
Fig. 4-3-1. Cyclic voltammetry curves of (a) BCNT_1Mg/Ni, (b) BCNT_3Mg/Ni, (c) BCNT_5Mg/Ni, and (d) BCNT_10Mg/Ni in the range... 72
Fig. 4-3-2. (a, b) ORR and (c, d) OER performances of various Mg and Ni ratio for BCNT_xMg/Ni: (a) LSV curves, (b) Tafel plots, (c) LSV curves, and... 73
Fig. 4-3-3. (a–c) ORR and (d–f) OER properties of f-Co/BCNT_10Mg/Ni, BCNT_10Mg/Ni, b-Co3O4, RuO2 and Pt/C: (a) LSV curves, (b) Tafel plots,... 77
Fig. 4-3-4. (a–c) ORR and (d–f) OER properties of f-Co/BCNT_10Mg/Ni and RuO₂: (a) LSV curves for various rotating speeds, (b) the corresponding K-L... 78
Fig. 4-3-5. Zn-air battery performances of f-Co/BCNT_10Mg/Ni, Pt/C-RuO2, and BCNT_10Mg/Ni: (a) polarization and corresponding power density curves,... 82
Fig. 4-3-6. XPS spectra of f-Co/BCNT_10Mg/Ni obtained after Zn-air battery testing: (a) Co 2p and (b) O 1 s. 83