- 學位論文
Organic-Inorganic Hybrid Electrolytes Based on PPG-PEG-PPG Diamine, Alkoxysilanes, and Lithium Perchlorate
Organic-Inorganic Hybrid Electrolytes Based on PPG-PEG-PPG Diamine, Alkoxysilanes, and Lithium Perchlorate
摘要
本論文主要研究添加不同比例聚矽氧烷 3-Glycidoxypropyl -trimethoxysilane(GLYMO)、3-(triethoxysilyl)propyl-isocyanate(ICPTES) 與高分子 ED2000反應生成乾式固態高分子電解質所造成的物性變化，以及在不同 Lithium perchlorate (LiClO4) 濃度下對導電行為的影響。 在鑑定方面主要分為幾個不同部分探討，首先藉由固態核磁共振(SSNMR) 與 FT-IR 確定高分子整體結構。再用 DSC 及 TGA 來觀察高分子的 Tg 變化與熱穩定性質，可與導電度結果作ㄧ比較。並用 SEM 幫助了解固態電解質表面型態及使用交流阻抗 (AC-impedance) 分析固態電解質在不同溫度下的離子導電度。另外利用固態核磁共振 (SSNMR) 研究鋰離子在固態電解質中的傳導機制與運動情形。 研究發現固態電解質在不同鋰鹽濃度下 Tg 會隨著鋰鹽濃度增加而上升，由導電度可發現隨著溫度不同會有明顯變化，主要是遵循 VTF model。另外，利用固態核磁共振 (SSNMR) 的 7Li T1 (自旋-晶格緩解時間) 及 7Li 譜寬實驗發現都有明顯的變化，證明在高分子中摻入鋰鹽的確會造成高分子之形態發生改變，對照 7Li 擴散係數實驗與導電度作ㄧ比較發現具有較高擴散係數的樣品同時具有較好的導電度，代表鋰離子在固態電解質中的傳遞情形與導電度有絕對的關聯。另外，在不同鋰鹽濃度下由 13C CP/MAS NMR 改變接觸時間實驗得知鋰離子和高分子鏈段形成暫時性鍵結導致高分子鏈運動變慢或者是分佈變廣而導致。藉由本研究可更深入了解鋰離子在固態電解質中的傳導情形，對於之後此領域的研究相信會有幫助。
關鍵字
電解質並列摘要
A novel organic-inorganic hybrid electrolyte based on the formation of ureasils through the reaction in different ratios of poly (propylene glycol)-block-poly (ethylene glycol)-block-poly (propylene glycol) bis (2-aminopropyl ether) (ED2000) with 3-isocyanatopropyltriethoxysilane (ICPTES), followed by the via the co-condensation of 3-Glycidoxypropyl -trimethoxysilane (GLYMO) in the presence of LiClO4, has been prepared. The structure and functionality of the materials thus obtained were characterized a variety of techniques including alternating current impedance, FT-IR spectroscopy, differential scanning calorimetry, and multinuclear solid-state NMR spectroscopy. The results of DSC measurements indicate the formation of transient cross-links between Li+ ions and the ether oxygens on complexation with LiClO4, resulting in an increase in the soft segment Tg. Behavior of ionic conductivity is Vogel-Tammann-Fulcher (VTF)-type. Solid-state NMR was used to probe the structure and dynamics of organic and inorganic components in the hybrid electrolyte and 13C cross-polarization/magic angle spinning NMR results from variable contact time measurements indicated that a significant decrease in the mobility of the polymer chains as the salt content was increased. 7Li NMR characterization was performed to study ionic mobility by measuring spectral line widths, T1 relaxation times, and diffusion coefficients. The results of the lithium diffusion coefficient measurements indicated that the ionic conductivity in the present electrolytes was mainly dominated by the mobility of the lithium cations.