固態電解質由於具有良好的機械強度，且其中不含液態的有機溶劑，因此安全性相較常見的液態電解質大大的提升。不過固態電解質仍面臨幾個問題，像是離子傳導度低、與電極的介面接觸較差等。本實驗利用聚醚高分子低熔點的特性，在組成電池以後，經過一到加熱的程序，使聚醚高分子能夠與電極產生濕潤的效果改善界面的問題，然而因為經過加熱以後，聚醚高分子的機械強度會大幅下降，可能導致電池短路，因此本實驗在其中導入電紡絲纖維膜，提供支撐的效果，大幅增加複合固態電解質的機械強度，另外由於電紡絲纖維膜的加入，能夠破壞部分聚醚高分子的結晶，因此在增加機械強度的同時，也提升了離子傳導度。
除此之外，為了更進一步提升電池的表現，本實驗將電紡絲纖維膜進行表面改質，將單離子傳導基修飾上其表面。在修飾上單離子傳導基以後，60 ℃下的離子傳導度由1.86×10-4 S/cm提升到了4.38×10-4 S/cm並透過電化學視窗可以看出此固態電解質具備良好電化學穩定性。隨後將其於60 ℃下進行電池效能的測試，經過改質的固態電解質在2C放電下的電容表現由45.5 mAh/g提升至85.2 mAh/g。另外，由對稱鋰金屬時效穩定性分析中，經過改質的阻抗出現大幅的下降，且在對稱鋰金屬循環測試裡也能觀察到，在400小時的循環測試後，經過改質的固態電解質依然維持良好的電壓穩定性。接著在60 ℃下進行1C長效循環充放電測試中可以看到200圈後電容維持率從本來的23.6 %提升到91.8 %，隨後將跑完200圈的鋰金屬的表面形貌進行分析，經過改質過後的固態電解質所形成的SEI(Solid electrolyte interphase)層更為平整且緻密。最後透過XPS(X-ray photoelectron spectroscope)證實導入單離子傳導基能夠使其先行與鋰金屬反應，抑制副反應的發生，形成更穩定的SEI層。證明了改質過後的電紡絲纖維膜以後，能夠有效的提升電池效能表現，並且由於單離子傳導基也能夠SEI層更均勻的沉積，因此也能夠提升電池的循環壽命。

In this study, taking advantages of the low melting point of Polyether , we do a thermal process after assemble of batteries. However, after the thermal process, the mechanical property PEO would become so poor that couldn’t maintain the dimensional stability which may lead to short circuit of the battery Therefore, we introduce the electrospun fiber as supporter which greatly improve the mechanical property of the solid electrolyte. In addition, we also modified the surface of the electrospun fiber to introduce single-ion conducting groups, which improve the ionic conductivity from 1.86×10-4 S/cm to 4.38×10-4 S/cm. Through the linear sweep voltammetry (LSV), we can observe that all of the composite solid electrolyte have electrochemical window up to 4.5 V, that indicate excellent electrochemical stability. Then, C-rate performance test was carried out at 60 ℃, the capacity of the modified solid electrolyte under 2 C discharge increased from 45.5 mAh/g to 85.2 mAh/g. Furthermore, from aging stability analysis, the impedance showed a significant drop after modification, also from the plating and stripping test, the modified solid electrolyte could maintain good stability after 400 hours. After that, in the 1C long-term cycle test at 60 ℃, we can found that the capacity retention increased from 23.6% to 91.8% after 200 cycle by modification. Surface morphology of lithium metal was analyzed by SEM after 200 cycles. The SEI (Solid electrolyte interphase) layer formed by the modified solid electrolyte is flatter and denser. Finally, we use X-ray photoelectron spectroscope(XPS) to analyze the chemaical structure of lithium surface after 200 cycle. From XPS spectra, we found that after the modification, the side reaction happened between lithium metal and electrospun fiber was inhibited. It is proved that the introduction of the modified electrospun fiber can effectively improve the capability with lithium metal, and improve the performance of lithium batteries.

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