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Characterization and Modulation of Electrochemical Processes at the Cathode-Electrolyte Interface in Lithium-Ion Batteries
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| 자료유형 | 학위논문 |
|---|---|
| 서명/저자사항 | Characterization and Modulation of Electrochemical Processes at the Cathode-Electrolyte Interface in Lithium-Ion Batteries. |
| 개인저자 | Fang, Shuyu. |
| 단체저자명 | The University of Wisconsin - Madison. Chemistry. |
| 발행사항 | [S.l.]: The University of Wisconsin - Madison., 2017. |
| 발행사항 | Ann Arbor: ProQuest Dissertations & Theses, 2017. |
| 형태사항 | 126 p. |
| 기본자료 저록 | Dissertations Abstracts International 81-01B. Dissertation Abstract International |
| ISBN | 9781085559416 |
| 학위논문주기 | Thesis (Ph.D.)--The University of Wisconsin - Madison, 2017. |
| 일반주기 |
Source: Dissertations Abstracts International, Volume: 81-01, Section: B.
Advisor: Hamers, Robert J. |
| 이용제한사항 | This item must not be sold to any third party vendors.This item must not be added to any third party search indexes. |
| 요약 | Advancement of battery technology requires cathode materials with high capacity and stable cycle performance. The application of high-voltage cathode such as LiNixMnyCo1-x-yO2 (NMC) poses new challenges in sustaining stable cathode-electrolyte interface, which is key to long-term performance. The solution is to be obtained through careful examination of electrochemical processes at the cathode-electrolyte interface and development of treatment strategies to modulate these processes.This thesis begins with an analytical study of the cathode-electrolyte interphase (CEI). X-ray photoelectron spectroscopy (XPS) is chosen as the primary characterization technique, and a combination of correlation analysis and binder-free cathode preparation method removes the ambiguity in peak assignation and CEI quantification. We have found, quite interestingly, that the CEI layer contains electrolyte decomposition products that originate from the anode side and then migrate to the cathode. It is also found that Al2O3 coatings can effectively reduce the deposition of anode-originated migrants. This work leads to new insight on the CEI concept and new design principles of cathode coatings. Following this work, Chapter 3 focuses on the development of Si-containing organic coatings. Through modulation of coating coverage, we achieved 27% improvement in capacity after 100 cycles. Mechanistic study with XPS, ICP, thermal mass spectrometry and impedance spectroscopy reveals a clear coverage-performance correlation. It is believed that the Si-containing coatings have two functions - facilitation of interfacial charge-transfer, and suppression of electrolyte decomposition. The hydrophobicity of coatings is identified as a key property for assisting lithium-ion desolvation at the interface. Finally, Chapter 4 presents a novel in situ method for battery failure diagnosis. Raman mapping technique is used to construct state-of-charge images of a working NMC cathode, which reveals the intrinsic inhomogeneity in the cathode failure process. |
| 일반주제명 | Chemistry. Physical chemistry. |
| 언어 | 영어 |
| 바로가기 | 
: 이 자료의 원문은 한국교육학술정보원에서 제공합니다. |
