본문 바로가기 주메뉴 바로가기
22대 대한민국 국회 국회정보길라잡이 국회의원검색
회원가입 로그인
HOME

정보검색

소장정보 검색

국회도서관 홈으로 정보검색 소장정보 검색

결과 내 검색

동의어 포함

고급검색

인명/단체명

저자정보 상세정보
인명/단체명을 입력하세요.

키워드

  • 대표어

  • 외국어

-

목차보기

Title Page

ABSTRACT

Contents

I. INTRODUCTION 16

1.1. The aim of calcium-ion battery research 16

1.2. Structure determination of cathode materials 16

1.3. Vanadium-based layered structure 17

1.4. References 19

II. THEORY 21

2.1. Electrochemistry 21

2.1.1. Rechargeable Batteries 21

2.1.2. Cathode Materials for Calcium-ion Batteries 22

2.1.3. Electrochemical techniques 22

2.2. Crystallography 25

2.2.1. X-ray Diffraction 26

2.2.2. Structure determination from powder X-day diffraction 27

2.2.3. Rietveld refinement method 27

2.2.4. Bond Valence Energy Landscape 27

2.3. References 30

III. A Poor Electrochemical Calcium-ion Intercalation Capability of H2V3O8 As an Example Showing the Ion Size Does Matter[이미지참조] 32

3.1. Introduction 32

3.2. Experimental 34

3.2.1. Synthesis and Materials Characterization 34

3.2.2. Electrochemical Characterization 34

3.2.3. Structural Analysis 35

3.2.4. Theoretical diffusion energy calculation 35

3.3. Results and discussion 36

3.3.1. Synthesis and Materials Characterization 36

3.3.2. Electrochemical Characterization 37

3.3.3. Bulk calcium intercalation investigation using an atomic-scale structural determination 39

3.4. Conclusions 41

3.5. References 59

IV. Metahewettite (CaV6O16·3H2O) as a High-Voltage Cathode Ma-terial for Nonaqueous Calcium-Ion Batteries[이미지참조] 63

4.1. Introduction 63

4.2. Experimental 65

4.2.1. Synthesis and Materials Characterization 65

4.2.2. Electrochemical Characterization 65

4.2.3. Structural Analysis 67

4.3. Results and discussion 68

4.3.1. Synthesis and Materials Characterization 68

4.3.2. Electrochemical Characterization 68

4.3.3. Elemental Analyses 70

4.3.4. Structure of Discharged Phase Ca2V6O16·3H2O and Mechanism Determination[이미지참조] 71

4.4. Conclusions 72

4.5. References 90

V. Novel layered aluminum vanadate as a good cyclability cathode for rechargeable Ca-ion batteries 94

5.1. Introduction 94

5.2. Experimental 96

5.2.1. Synthesis and Materials Characterization 96

5.2.2. Electrochemical Characterization 96

5.2.3. Structural analysis 97

5.3. Results and discussion 98

5.3.1. Synthesis and Materials Characterization 98

5.3.2. Electrochemical Characterization 99

5.3.3. Elemental analysis of Al0.71V3O8·2.3(H₂O)[이미지참조] 100

5.4. Conclusions 102

5.5. References 114

요약문 117

List of Tables

Table 3.1. Crystallographic data and powder XRD Rietveld refinement results for H2V3O8: atomic...[이미지참조] 54

Table 3.2. Selected interatomic distances (Å) in the structure of H2V3O8 at room temperature.[이미지참조] 55

Table 3.3. ICP-OES analysis for vanadium dissolution in the electrolyte. 55

Table 3.4. Elemental ratios estimated from the ICP-OES analysis for the pristine and different potential... 56

Table 3.5. Crystallographic data and powder XRD Rietveld refinement results for Ca0.17H2V3O8: atomic...[이미지참조] 57

Table 3.6. Pristine and Simulated H2V3O8 unit cell parameters, volume and energy level.[이미지참조] 58

Table 4.1. Crystallographic data and powder XRD Rietveld refinement results for CaV6O16·3H2O: atomic...[이미지참조] 85

Table 4.2. Selected interatomic distances (Å) in the structure of CaV6O16·3H2O at room temperature.[이미지참조] 86

Table 4.3. The ICP-OES analysis for vanadium dissolution in the electrolyte. 87

Table 4.4. Elemental ratios estimated from the ICP-OES analysis for the pristine and different potential... 87

Table 4.5. Crystallographic data and powder XRD Rietveld refinement results for Ca2V6O16·3H₂O:...[이미지참조] 88

Table 4.6. Selected interatomic distances (Å) in the structure of Ca2V6O16·3H2O at room temperature.[이미지참조] 89

Table 5.1. Elemental ratios estimated from ICP analysis for Al0.71V3O8·2.3(H₂O).[이미지참조] 113

Table 5.2. Elemental ratios estimated from ICP analysis for the pristine Al0.71V3O8·2.3(H₂O), first discharged,...[이미지참조] 113

List of Figures

Figure 2.1. Scheme of the home-made cell used for electrochemical characterizations. 24

Figure 2.2. The illustrations of Bragg's Law. 26

Figure 3.1. (a) The crystal structure of H2V3O8 with V(1)O6 octahedra (blue) and V(2)O5 (green) and...[이미지참조] 42

Figure 3.2. Thermo-gravimetric analysis for H2V3O8 under nitrogen flowing atmosphere.[이미지참조] 43

Figure 3.3. Scheme of the home-made cell used for electrochemical characterizations. 44

Figure 3.4. (a) Initial galvanostatic discharge-charge profiles between -0.3 V and 0.9 V (vs AC) at... 45

Figure 3.5. Ferrocene test used to estimate Ca/Ca2+ voltage. (a) (b) CV of H2V3O8 electrode at 0.05 mV/s...[이미지참조] 46

Figure 3.6. Plot of cathodic peak current (A g-1) dependence on the root scan rate (mV1/2 s-1/2).[이미지참조] 47

Figure 3.7. Galvanostatic cycling performance at 20 mA g-1 for 30 cycles at 60 ℃ (black: discharge capacity,...[이미지참조] 48

Figure 3.8. SEM images of the pristine and the 30th charged state of the H2V3O8 electrodes.[이미지참조] 48

Figure 3.9. The XRD patterns of pristine and 30th charged electrode to 0.9 V vs AC.[이미지참조] 49

Figure 3.10. (a) X-ray diffraction (XRD) patterns of CaxH2V3O8 (0 ≤ x ≤ 0.17) at different potential point...[이미지참조] 50

Figure 3.11. Thermo-gravimetric analysis for initial electrode (black-H2V3O8), 1st discharged electrode (red-...[이미지참조] 51

Figure 3.12. (a) (010) view of the observed Fourier map for Ca0.17H2V3O8. The map's width and thickness...[이미지참조] 52

Figure 3.13. 3D bond valence energy level maps for pristine and simulated H2V3O8 with iso-surfaces of the...[이미지참조] 53

Figure 4.1. Thermo-gravimetric analysis for CaV6O16·3H2O under nitrogen flowing atmosphere.[이미지참조] 73

Figure 4.2. (a) The crystal structure of CaV6O16·3H2O (b) Powder X-ray diffraction pattern recorded at...[이미지참조] 74

Figure 4.3. Schematic diagram of the fabricated home-made cell used for electrochemical... 75

Figure 4.4. (a) Initial discharge/charge galvanostatic profiles for CaV6O16·3H2O in 0.5 M Ca(ClO₄)2 in...[이미지참조] 76

Figure 4.5. (a) Cyclic voltammograms of CaV6O16·3H2O in 0.5 M Ca(ClO₄)₂ in EC/DEC (1:1 volume...[이미지참조] 77

Figure 4.6. Ferrocene test used to estimate Ca/Ca2+ voltage.[이미지참조] 78

Figure 4.7. CV of CaV6O16·3H2O electrode at 0.05 mV/s in a 0.5 M Ca(ClO₄)₂ in EC/DEC (1:1 v/v) with...[이미지참조] 79

Figure 4.8. Thermo-gravimetric analysis for initial electrode (black- CaV6O16·3H2O), 1st discharged...[이미지참조] 80

Figure 4.9. (a) Log i(A) vs. log ν plot of the peak current according to the scan rate to determine the b... 81

Figure 4.10. (a) The variation of unit cell parameters and volume during the discharge-charge cycle. X-... 82

Figure 4.11. Ex-situ XRD contour map of CaxV6O16·3H2O (1 ≤ x ≤ 2) electrodes during the first cycle...[이미지참조] 83

Figure 4.12. (a) The powder X-ray Rietveld refinement profile for discharged, Ca2V6O16·3H2O, recorded...[이미지참조] 84

Figure 5.1. CV of Al0.71V3O8·2.3(H₂O) electrode at 0.2 mV s-1 in 0.5 M Ca(ClO₄)₂ in EC/DEC with Ag/Ag+...[이미지참조] 103

Figure 5.2. Ferrocene test to estimate Ca/Ca2+ voltage.[이미지참조] 104

Figure 5.3. (a) Le Bail profile, (b) Expected crystal structure, (c) TGA graph, (d) XPS result, (e) and (f)... 105

Figure 5.4. Raman spectrum of the Al0.71V3O8·2.3(H₂O) with/without graphene.[이미지참조] 106

Figure 5.5. TEM image of the Al0.71V3O8·2.3(H₂O) with graphene.[이미지참조] 107

Figure 5.6. Illustration of home-made cell for electrochemical properties. 108

Figure 5.7. (a) Initial galvanostatic discharge-charge profiles at a current density of 20 mA g-1, (b) Second... 109

Figure 5.8. (a) Ex-situ XRD patterns, (b) HR-TEM images, and (c) TEM-EDX mapping for pristine, 1st discharge,... 110

Figure 5.9. (a) ICP and EDX results, (b) FTIR spectrums, and (c-d) XPS survey spectra of Ca 2p, and V 2p, for... 111

Figure 5.10. TGA graph after discharged. 112

초록보기

현 리튬이온 전지의 이론적 한계는 셀 기준 300 Wh/kg 정도이며 이론적 한계까지 개발된다 해도 전기 자동차용으로 요구하는 500Wh/kg 에 훨씬 못 미친다. 이에 2025 년 이후를 대비할 수 있는 높은 에너지 밀도 및 높은 가격 경쟁력을 가지는 혁신 전지의 개발이 요구되고 있다. 칼슘 이온 (Ca2+) 전지는 이론적 관점에선 리튬 이차전지에 비해 2 배의 용량을 가지는 혁신 미래 전지로 여겨지나, 무겁고 크기가 큰 칼슘 이온의 낮은 이동성 때문에 전극 재료의 개발이 어려워 전 세계적으로 연구 결과가 거의 없는 미개척 분야이다.

이 논문에서는 H2V3O8, CaV6O16·3H2O, 및 Al0.71V3O8·2.3(H2O)에 대하여 칼슘 이차전지용 양극 소재의 가능성을 연구하였다. 특히, 다양한 소재들 중에서도 바나듐 기반 층상 구조에 초점을 맞추어 전기화학적 특성 뿐만 아니라, 구조적 특성에 대해 깊이 연구하였다. 재료의 형태 분석 및 원소분석은 SEM, TEM, TG, EDX, ICP, FTIR 및 XPS 와 같은 기법을 사용하여 분석을 하였으며, 전기화학적 분석은 Cyclic voltammetry, Galvanostatic charge/discharge 를 이용하여 물질의 용량, 전압, 반응 메커니즘 (diffusion controlled reaction, surface limited reaction)에 대한 연구를 하였다. 구조 결정학을 기초로 하여 반응 메커니즘을 하였으며, 3 차원 전자 밀도 맵으로 변환 후 삽입된 이온의 위치를 분석하였다.

추천서가 (다양한 추천 자료를 만나보세요)

권호기사보기

권호기사 목록 테이블로 기사명, 저자명, 페이지, 원문, 기사목차 순으로 되어있습니다.
기사명 저자명 페이지 원문 기사목차

권호

기사명 원문보기 기사목차
닫기