離子交換薄膜一直都是燃料電池、釩液流電池或是各種能量儲存裝置最核心的部分。至今，釩液流電池的質子交換膜仍有幾個缺點有待改善，如(1)提高質子導電度、(2)降低釩離子滲透、(3)良好的耐久穩定性。 本研究利用具有高化學穩定度和機械強度的高分子材料PSU添加至SPEEK高分子中，並在外加電場下鑄造成質子交換膜。結果顯示，添加PSU確實改善複合薄膜的物理性質(降低膨潤率、釩離子滲透等)，且經由電場誘導後，SPEEK和PSU高分子受到電場極化，使薄膜中的親水孔道在垂直於薄膜表面的方向形成具有方向性且連續的緻密結構，因為此緻密結構，使大顆粒釩離子更不容易傳遞，更進一步降低釩離子的滲透，提升薄膜的質子選擇率。添加PSU高分子至SPEEK中所製備的有機複合薄膜，在經電場誘導後，S57/PSU-20+E薄膜的釩離子滲透率下降0.195×10−7 cm2/min，質子選擇率達到16.53×104 S min/cm3。在單電池的測試中，S57/PSU-20+E薄膜比起其他薄膜擁有較好的庫倫效率、能量效率，且在經過10圈充放電次數後，電容量保持率也明顯的優於市售的N117。 此一新穎至被薄膜的方法同時改進了多項物性，解決膜材開發面臨的兩難情況，該方法也能廣泛地應用於各種不同再生能源裝置的零件開發。 ;The ion exchange membrane is the most important component in fuel cell or vanadium redox flow battery. There are few drawbacks on vanadium redox flow battery membrane. These disadvantages include: (1) Low proton conductivity, (2) High vanadium ion permeability, and (3) Insufficient chemical stability and mechanical strength for prolonged operation. Present research examined the property of SPEEK and PSU blend and verify its applicability in Redox vanadium flow battery. The use of external electric field poling in the composite polymer system created preferentially ordered channel morphology with high structural integral hydrophobic region in the membrane, which has shown to effectively improved the ion conductivity, reduced the vanadium ion permeation, and raised the mechanical and chemical strength. The study has demonstrated that electric poling treatment created membrane bearing preferentially ordered hydrophilic channel morphology and densely packed hydrophobic region. Due to more densely packed amorphous hydrophobic domain, the membrane showed lower degree of vanadium ion permeability and higher degree of ion selectivity. The composite membrane of S57/PSU-20+E shows the vanadium ion permeability only 0.195×10−7 cm2 min−1, the ion selectivity up to 16.53×104 S min/cm3. In the VRB performance, S57/PSU-20+E membrane shows the better performance in Coulombic Efficiency and Energy Efficiency. After 10 cycles, the discharge capacity retention of S57/PSU-20+E is still superior to N117. This approach resolved the long standing dilemma of high performance membrane developments encounter in many renewable energy technologies.
