Electrochemical properties of Si-metal film as an material for lithium ion secondary batteries
- 주제(키워드) lithium ion secondary batteries , silicon thin film , co-sputtering
- 발행기관 고려대학교 대학원
- 지도교수 변동진
- 발행년도 2008
- 제출일 2008-06-30
- 학위수여년월 2008. 8
- 학위명 석사
- 학과 일반대학원 신소재공학과
- 세부전공 신소재공학전공
- 원문페이지 57 p
- 본문언어 영어
- 제출원본 000045503117
초록/요약
Silicon is recognized as one of the most promising candidate for the anode materials for lithium ion secondary batteries due to its theoretical capacity of 4200mAh/g, which is far greater value than that of carbon (LiC6, 372mAh/g). However one of the major problems of this material is the large volume change occurring during Li insertion/extraction, which result in mechanical cracking and poor cycling stability of the electrodes. It has been previously reported that alloying the Si with electrochemically inactive elements may enhance the electrochemical performance. In this study, the electrochemical properties of amorphous Si thin film electrodes their derivatives have been investigated. The samples had two different geometries. The Si thin film sputtered directly on the copper foil substrate, Si and Ti co-sputtered on the copper foil substrate. The effects of the annealing process had also been evaluated. The electrochemical performance of as-deposited and annealed samples for both geometries were studied by galvanostatic charge/discharge. The structures, the composition and the morphologies at the samples were characterized by X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscopy (SEM), respectively.
more목차
1. Introduction 1
2. Theoretical background 3
2.1 Lithium ion secondary battery 3
2.1.1 Cathode active materials 7
2.1.2 Anode active materials 9
2.1.2.1 Lithium metal 9
2.1.2.2 Carbon material 11
2.1.2.3 Silicon based material 12
2.1.3 Electrolyte 14
2.1.4 Separator 16
2.2 Sputtering 17
2.2.1 Glow discharge 17
2.2.2 Magnetron sputtering 18
3. Experimental 22
3.1 Deposition of Si film 22
3.2 Deposition of Si/M co-sputtering 22
3.3 Electrochemical test 27
3.4 Characterization of active materials 27
4. Results and Discussion 29
4.1 Effects of Si film on copper foil with annealing 29
4.2 Effects of Ti-Si composite film on copper foil 38
5. Conclusions 44
Reference 45
