本研究分為兩部分，第一部份利用聚(N-乙烯甲醯胺)(PNVF)作為固化劑，摻入LiTFSI/Acetamide共熔鹽(莫耳比1/2)，製成高分子共熔鹽膠態電解質；高分子含量的提高，雖然能有效提升機械性質，卻會降低電解質的導離子度，經實驗結果發現物性與導離子度在本系統中無法同時兼顧，因此引入PVDF濾膜作為骨架，使物性與導離子度能達到平衡，使得充放電可以順利進行。我們探討了不同莫耳比例的共熔鹽與不同含量的高分子對於物性與電性表現的影響，其中表現最穩定的比例為：LiTFSI/Acetamide共熔鹽(莫耳比1/2)摻10 wt%的PNVF含進PVDF濾膜中成膜，其室溫導離子度為5.1 x 10-5 S/cm；電化學穩定窗口接近4 V vs Li/Li+；0.05C-rate 慢速充放電電容量達120 mAh/g，十圈後電容量衰退將近20%，導離子度不足導致0.1C-rate充放電僅能達到40 mAh/g。由實驗結果推測電容量衰退的原因有二，一是用水作為溶劑會被高分子網絡困住無法被製程去除乾淨，留在電解質中持續於充放電過程發生反應；二是Acetamide作為電解質在充放電過程中持續與電極材料發生副反應。

第二部分使用PVDF-HFP作為固化劑取代PNVF，並使用丙酮作為溶劑，改良第一階段用水作為溶劑而無法去除乾淨的隱憂，並使用N-methylacetamide(MAc)取代Acetamide作為共熔鹽，改良Acetamide會與電極發生副反應的影響；此高分子共熔鹽電解質依舊有物性不佳的缺陷，因此亦引入PVDF濾膜作為骨架以穩定電性表現。我們以LiTFSI/MAc共熔鹽(莫耳比1/4)摻入20 wt%的PVDF-HFP獨立成膜製成電解質，其室溫離子傳導度為2.9 x 10-4 S/cm，摻入濾膜後降至1.3 x 10-4 S/cm；電化學穩定窗口不論有無濾膜都接近5 V vs Li/Li+，顯濾膜在本本系統中為惰性，不參與電化學反應；充放電速率能力測試，獨立成膜的電解質於0.3C第一圈放電達100 mAh/g，含濾膜的電解質0.5C第一圈放電達80mAh/g；循環壽命測試，獨立成膜的電解質由於機械性質不佳，使用0.1C充放電第一圈放電量150 mAh/g，三十圈後放電量僅有60 mAh/g，電容量僅保留40 %，摻入濾膜後的循環壽命測試，0.1C充放電第一圈放電量160 mAh/g，五十圈後放電量仍為160 mAh/g，庫倫效率保持100 %，此結果顯示摻入濾膜作為骨架，不僅提升電解質的機械性質，更驗證了電解質的機械性質對於電池的循環壽命有極大的影響。

We introduce deep eutectic solvent (DES)-polymer composites as a promising candidate for solid composite electrolytes. The first part of this study is the use of poly(N-vinyl formamide) as hardener for polymer-eutectic salt composite electrolytes for lithium ion batteries. We use eutectic salt which is composed of lithium bis(trifluoromethane sulfone)imide (LiTFSI) and acetamide at a molar ratio of 1:2 (LiTFSI:Acetamide, L1A2), and the composition of electrolyte is L1A2/PNVF (90/10 wt%). The DES-based gel electrolytes are characterized by high ionic conductivity (0.2 mS/cm, @RT), and electrochemical stability (3.9 V vs Li/Li+). A Li/LiFePO4 test cell was constructed using the above mentioned composite electrolytes, and shows capacities of 120 mAh/g at 0.05C at first discharge.
The second part of this study is the use of Poly(vinylidene fluoride-co-hexafluoropropylene) as hargener for polymer-eutectic salt composite electrolytes. We use eutectic salt which is composed of LiTFSI and N-Methylacetamide at a molar ratio of 1:4 (LiTFSI: N-Methylacetamide, L1M4), and the composition of electrolyte is L1M4/PVDF-HFP (90/10 wt%). The DES-based gel electrolytes are characterized by high ionic conductivity (0.3 mS/cm, @RT), and electrochemical stability (4.9 V vs Li/Li+). A Li/LiFePO4 test cell was constructed using the above mentioned composite electrolytes, and shows capacities of 160 mAh/g at first discharge, and can also perform stable cycling of over 50 cycles at 0.1C.

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