DC Field | Value | Language |
---|---|---|
dc.contributor.advisor | Pyun, Su-Il | - |
dc.contributor.advisor | 변수일 | - |
dc.contributor.author | Go, Joo-Young | - |
dc.contributor.author | 고주영 | - |
dc.date.accessioned | 2011-12-15 | - |
dc.date.available | 2011-12-15 | - |
dc.date.issued | 2005 | - |
dc.identifier.uri | http://library.kaist.ac.kr/search/detail/view.do?bibCtrlNo=244828&flag=dissertation | - |
dc.identifier.uri | http://hdl.handle.net/10203/49816 | - |
dc.description | 학위논문(박사) - 한국과학기술원 : 신소재공학과, 2005.2, [ xxi, 271 p. ] | - |
dc.description.abstract | The present work is concerned with lithium transport through non-fractal and fractal $Li_{1-δ}CoO_2$ film electrodes using quasi-steady-state and transient electrochemical methods based upon fractal geometry. In chapter III, stresses generated during lithium transport through the rf sputter-deposited $Li_{1-δ}CoO_2$ films with different thicknesses were investigated by a double quartz crystal resonator (DQCR) technique. In situ resonant frequency changes of the $Li_{1-δ}CoO_2$ -coated AT- and BT-cut quartz crystals were first recorded along with the galvanostatic charge (lithium deintercalation) and discharge (lithium intercalation) curves obtained in a 1 M $LiClO_4-PC$ solution. From the measured resonant frequency changes, the lateral stresses of the $Li_{1-δ}CoO_2$ films were then estimated as a function of lithium stoichiometry (1-δ). Compressive and tensile stresses were developed in the $Li_{1-δ}CoO_2$ films during the lithium deintercalation and intercalation, respectively. The remarkable variation of compressive and tensile stresses with lithium stoichiometry appeared in a two-phase (a Li-poor alpha-phase and a Li-rich β-phase) region. Compressive and tensile stresses decreased in absolute magnitude with increasing film thickness. The contribution of the electrostrictive stress to the total stress was theoretically calculated to be about $2.2×10^{-3}$ %. From the extremely small contribution of the electrostrictive stress, it is strongly suggested that stresses result mainly from the volume contraction and expansion of the $Li_{1-δ}CoO_2$ films due to the lithium intercalation and deintercalation, respectively. Furthermore, it is experimentally confirmed that the relaxation of compressive stress is developed during the lithium deintercalation in a single-alpha-phase region, causing the cracking of the $Li_{1-δ}CoO_2$ films. In chapter IV, ionic diffusion through electrolyte towards self-affine fractal electrode was experimentally investigated under the ... | eng |
dc.language | eng | - |
dc.publisher | 한국과학기술원 | - |
dc.subject | Lithium transport | - |
dc.subject | Surface roughness | - |
dc.subject | Intercalation-induced stress | - |
dc.subject | 프랙탈 | - |
dc.subject | 리튬 코발트 산화물 박막 전극 | - |
dc.subject | 리튬 이동 | - |
dc.subject | 표면 거칠기 | - |
dc.subject | 인터칼레이션에 의해 유발되는 응력 | - |
dc.subject | Fractal | - |
dc.title | Lithium transport through non-fractal and fractal $Li_{1-5}CoO_2$ film electrodes using quasi-steady-state and transient electrochemical methods based upon fractal geometry | - |
dc.title.alternative | 프랙탈기하학을 바탕으로 준정상상태/시간추이 전기화학방법을 이용한 비프랙탈/프랙탈 형상의 리튬 코발트 산화물 박막 전극내에서의 리튬 이동에 관한 연구 | - |
dc.type | Thesis(Ph.D) | - |
dc.identifier.CNRN | 244828/325007 | - |
dc.description.department | 한국과학기술원 : 신소재공학과, | - |
dc.identifier.uid | 020015015 | - |
dc.contributor.localauthor | Go, Joo-Young | - |
dc.contributor.localauthor | 고주영 | - |
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