本文以薄型PEMFC作為目標,主要分為組裝模擬與電池測試兩個方向。組裝模擬的部分,對於薄型的金屬雙極板,容易因壓力不均,造成撓曲的現象發生,因此影響電池之效能。此現象在電池堆中,將隨著電池單元數的增加而更為顯著。研究中以改善雙極板撓曲現象作為出發點,提出新型之端板設計,探討加壓端板對單電池的影響。電池測試的部分,則是以評估金屬雙極板取代石墨的可能性作為主軸,研究中分別進行石墨、鋁合金、不銹鋼等單電池之測試,包括阻抗量測及效能測試,藉此了解金屬雙極板與傳統石墨之差異。 新的端板,以集中施力於反應面積的概念作為設計方向。各個不同之端板,利用有限元素分析,模擬薄型PEMFC在不同的端板組裝下,MEA的應力分布與GDL壓縮量均勻度。再利用感壓軟片取代MEA進行組裝的實驗,藉此驗證模擬之正確性。而透過應力、壓縮量之分析討論,再以最佳之端板進行電池堆之模擬,探討電池堆各cell壓力的分布及衰減的情形。 單電池測試中,由阻抗的量測開始,包括材料阻抗及接觸阻抗之量測,並整合頻率響應分析儀量測單電池反應時之高頻阻抗,了解不同雙極板對燃料電池內電阻之影響。接著以效能測試探討金屬雙極板取代石墨的可行性,並且組裝一電池堆進行效能測試。此外,並以模擬中最佳之端板實際進行效能測試,探討端板設計對電池效能所帶來之影響。 研究之結果,新的端板設計在MEA應力分布、GDL壓縮量均勻度及電池的效能上,確實有正面的貢獻,成功地建立燃料電池堆模擬組裝與實驗驗證之技術。而電池測試中,鋁合金與鍍金雙極板,若能在材料改質與製程上有所突破,將有很大的機會取代石墨。
The pressure distribution of fuel cell stack assembly may greatly affect the cell performance. Because of the better mechanical properties of metals, thin metallic bipolar plates tend to deform more easily under un-even stacking pressure.In this study, various designs of end plates were studied and analyzed by FEM for pressure distribution and GDL compliance. Experiments were also conducted and by measuring pressure distribution of pressure films to verify the numerical analyses results. A fuel cell stack is assembled based on the best end plate design from FEM simulation and experiments. The pressure distribution of each cell can be measured by replacing the membrane with pressure film. The GDL compliance values were also measured. In order to check the validity of the simulation model, these measurement data were compared with the simulation results. Hence, the simulation procedures were established for future thin metallic PEM fuel cell stacking parameters and end plate design. Finally, the performance of single cells are compared. The results show that the stack assembly design has great effects on cell performance. The assembly design of placing a thin elastic silicon pad between the end plates and bipolar plates provide the most uniform pressure distribution and significant improvement on cell performance.