傳統型的二次鋰電池使用有機電解液作為電解質，然而液態電解液有漏液、易燃、鋰枝晶生成以致嚴重易短路等風險，在追求安全及效能最大化的時代，如何提高電池的能量密度及安全性是一大課題。本論文研究將共熔鹽導入高分子交聯網絡製成共熔鹽膠態電解質（EGPE）並應用於鋰電池。具體而言，我們首先將雙三氟甲烷磺醯亞胺鋰（Lithium bis(trifluoromethanesulfonyl)imide，LiTFSI）與N-甲基乙醯胺（MAc）配製成共熔鹽，再與單體及交聯劑一同進行紫外光聚合，單體除丙烯酸丁酯（BA）外，另添加丙烯睛（AN）以增進電池效能。將聚合後之電解質薄膜進行導離子度、線性掃描伏安法並組成電池進行充放電、循環壽命及循環掃描伏安法測試，了解電解質的電化學特性。本研究之電解質最佳比例EGPE-2於室溫下導離子度為5.22×10-4 S/cm，電化學穩定窗口為0.5 ~ 4.9 V（vs. Li/Li+），其搭配磷酸鋰鐵（LFP）正極與鋰金屬負極之半電池在1 C之電容量可達110 mAh/g，0.2 C循環壽命達250圈以上，相較於直接將共熔鹽作為液態電解液使用有更高的電容量、循環壽命、電化學穩定性及可逆性。利用電化學阻抗頻譜法、鋰枝晶測試、SEM證明電解質的界面穩定性高，能有效抑制鋰枝晶的生長，使SEI層平均地增厚，藉由拉曼光譜、DSC、TGA的分析說明將共熔鹽導入高分子網絡後，熱穩定性及電化學特性改善的同時共熔鹽本身的特性並沒有發生改變。

This work studies the effect of the deep-eutectic solvent (DES) into polymer cross-linking network to prepare eutectic gel-type polymer electrolyte (EGPE) for applications to the secondary lithium batteries. First, the DES is composed of N-methyl acetamide (MAc) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). Subsequently, monomers and cross-linkers were dissolved in DES to facilitate polymerization by UV-curing. Within the polymer framework formed by butyl acrylate (BA), trimethylolpropane triacrylate (TMPTA), and 1,6-hexanediol diacrylate (HDDA), acrylonitrile (AN) was introduced to improve the performance of lithium batteries. The EGPEs are characterized by high ionic conductivity (5.22×10-4 S/cm), electrochemical stability (up to 4.9 V vs. Li/Li+), and thermal stability (up to 150 ℃). The potentiality of EGPEs for applications in lithium batteries is substantiated by the galvanostatic charge-discharge test of LiFePO4 | EGPE | Li cells. The capacity reaches 110 mAh/g at 1 C and the cycling results are over 250 cycles at 0.2 C. The stability of SEI layer is proved by impedance analysis, dendrite test and the SEM image of lithium metal. Raman spectrum, DSC, and TGA illustrate that the thermal stability and electrochemical properties of EGPEs are improved while the properties of the DES itself have not changed.

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