具尿素官能基之雙核狀固(膠)態高分子電解質結構鑑定與動力學研究

Synthesis, Structure Characterization, Ionic Conductivity and Dynamic Properties of Double Core-branched Hybrid Electrolytes Based on Ureasils

陳禹翰(Yu-Han Chen)

指導教授 ： 高憲明

國立中央大學/理學院/化學系/碩士(2011年)

摘要

本論文研究對具有尿素官能基之雙核狀高分子電解質進行結構鑑定及動力學研究，利用三聚氯氰作為結構核心，以三嵌段共聚高分子 ED2000 作為連接，之後接上 ED2000 與異氰酸酯矽氧烷3-isocyanate propyltriethoxysilane (ICPTES) 反應之含尿素官能基前驅物，形成雙核狀結構的有機無機高分子電解質。
研究可分為兩大部分，第一部分以固態高分子電解質為研究主題，藉由摻雜不同濃度之鋰鹽 (LiClO4) ，探討其對於高分子電解質的性質影響及鋰離子與高分子鏈段的作用情形，利用熱重分析儀 (TGA) 探討熱穩定性，以微差掃描卡計 (DSC) 研究高分子鏈段結晶情形，傅立葉紅外線吸收光譜儀 (FTIR) 分析鋰鹽解離程度，交流阻抗分析儀 (AC-Impedance) 測量導電度、電化學穩定性及鋰離子遷移係數，以掃描式電子顯微鏡 (SEM) 分析表面型態及固態核磁共振光譜儀 (Solid State NMR) 進行動力學分析研究。
第二部分以膠態高分子電解質為研究主題，藉由合成之高分子電解質吸附含有不同鋰鹽之有機液態電解液，探討其電解液吸附程度，以交流阻抗分析儀 (AC-Impedance) 測量導電度、電化學穩定性及鋰離子遷移係數，並由固態核磁共振光譜儀 (Solid State NMR) 進行鋰離子擴散係數測試。

關鍵字

固態核磁共振 ； 鋰離子電池 ； 高分子電解質

並列摘要

The development of polymer electrolytes with high ionic conductivity has received considerable attention because of their potential applications in many solid electrochemical devices such as high-energy density batteries, chemical sensors, and light-emitting devices. Organic-inorganic hybrid electrolytes doped with LiClO4 and based on tri-block copolymer poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) bis(2-aminopropyl ether) (H2N-PPG-PEG-PPG-NH2), 3-isocyanatepropyltriethoxysilane (ICPTES) and central core 2,4,6-trichloro-1,3,5-triazine (cyanuric chloride, cc) have been synthesized by sol-gel process to get a double core-branched structure.
The structural and dynamic properties of the materials were systematically investigated by a variety of techniques including thermo gravimetric analyzer (TGA), AC impedance, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscope (SEM), 13C cross-polarization magic-angle spinning (CPMAS) NMR measurement and with varying contact times, 1H-13C 2D WISE (wide-line separation) NMR measurements. A VTF (Vogel- Tamman-Fulcher)-like temperature dependence of ionic conductivity was observed for all the hybrid electrolytes studied, implying that the diffusion of charge carriers was assisted by the segmental motions of the polymer chains. The Li-ion mobility was determined from 7Li static NMR line width measurements and correlated with their ionic conductivities. A maximum ionic conductivity value of 6.22 × 10-5 S/cm was obtained at 30 ?C for the hybrid electrolyte with a [O]/[Li] ratio of 32.
Also present the swelling ratio of the electrolyte membrane is measured with different electrolyte solvents and found to be very high in comparison to other reported polymer electrolyte membrane. The membrane exhibits ionic conductivity value near to 10-2 S/cm. The high ionic conductivity of the electrolyte membrane is attributed to the higher percentage of swelling as it can retain sufficient amount of electrolyte solvent, thus creating channels for free movement of ions. The membrane also depicts higher electrochemical stability window versus Li/Li+, which is required for practical battery applications.

並列關鍵字

Lithium ion battery ； Polymer electrolyte ； Solid-state NMR

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