Electrochemical properties of Si/Fe multilayer film anode for Lithium secondary batteries
- 주제(키워드) Si/Fe multilayer film anode for Lithium secondary batteries
- 발행기관 고려대학교 대학원
- 지도교수 이성래
- 발행년도 2011
- 학위수여년월 2011. 2
- 학위구분 석사
- 학과 일반대학원 마이크로/나노시스템협동과정
- 원문페이지 74 p
- 실제URI http://www.dcollection.net/handler/korea/000000025854
- 본문언어 한국어
- 제출원본 000045642347
초록/요약
Silicon is an attractive candidate for anode material in Li-ion batteries owing to their huge theoretical capacity, but the problems related to volume expansion still remain. Here we report that the buffer roles intensified Si/Fe multilayer film electrode, which consist of amorphous silicon layers and polycrystalline Fe layers, can achieved stable cycle life performance with high capacity as anode for Li-ion batteries. In the Si/Fe multilayer electrode, decreasing the Fe layer thickness give advantage in capacities, which connected to fast transport of the Li ion, but cyclic performance degradation were found with extended cycle. In contrast, increasing the thickness of inactive Fe buffer layers and number of deposit stack enhance the long-term strength and fracture toughness, which lead to extended cycle life with high reversibility as well as maintained the integrity of multilayer structured on cycles. The geometrical properties in the Si/Fe multilayer electrode annealed at 100°C for 5min that the random oriented polycrystalline Fe layer including partial silicide phases formed cause both suppression of the Fe layer deformation and improving the diffusivity of Li with stable cyclic performance and high reversible capacity. In addition, we demonstrate that adhesion promoted Ti under layer improving the cycle life performance of Si/Fe multilayer with thin Fe layer. These stable cyclic performances with high reversibility and structural integrity maintained attribute to strengthen buffer roles in the Si/Fe multilayer electrodes, which suitable for very high reversibility and long cycle life properties demanded electrical devices.
more목차
Abstract …………………… 1
1. Introduction …………………… 4
2. Literature Review …………………… 10
2.1 Cathode materials …………………… 13
2.2 Electrolyte …………………… 16
2.3 Anode materials …………………… 17
2.3.1 Bulk Si …………………… 18
2.3.2 Thin film Si …………………… 21
2.3.3 Si/TM and Si-TM film anode …………………… 22
3. Experimental Procedure …………………… 25
4. Results and Discussion …………………… 27
4.1 Fe thickness effect on electrochemical properties ……… 27
4.2 Ti underlayer effect on electrochemical properties ……… 36
4.3 Annealing effect on electrochemical properties ……… 37
4.4 Electrode structure effect (Top Fe layer effect) on electrochemical properties ……… 44
4.5. Number of bilayer effect on electrochemical properties. ……… 46
5. Conclusions …………………… 47
6. Reference …………………… 49
