本研究使用鈦網作為質子交換膜燃料電池膜電極組中之氣體擴散層，取代目前常見且成本較高之碳紙。然而鈦金屬表面容易氧化形成二氧化鈦，將降低鈦網電子傳導率，增加接觸阻抗，故本研究以鹽酸酸洗製程使鈦網表面形成具抗氧化能力之氫化鈦層，提升其應用於低溫質子交換膜燃料電池中之抗氧化力與燃料電池之電流輸出。 研究中先以不同孔徑之鈦網取代低溫質子交換膜燃料電池膜電極組中陰極之碳紙氣體擴散層比較其性能，再以鹽酸酸洗鈦網提升鈦網在燃料電池中之抗氧化能力，實驗表明酸洗製程可顯著提升鈦網之抗氧化性，避免氧化物之生成，降低燃料電池之活化阻抗，與無酸洗之鈦網比較可提升燃料電池電流密度達33.6%。本研究開發最佳酸洗鈦網組裝為燃料電池時，操作於70 oC、1 atm空氣、0.6 V下所測得之電流密度為1782.1 mA/cm2，當氣體壓力於2 atm時，性能可提升至2428.1 mA/cm2，在相同測試條件下與商用碳紙相當，證實可取代碳紙作為低溫型質子交換膜燃料電池陰極端氣體擴散層之可用性。 ;This study aims to develop a low-cost gas diffusion layer for low-temperature proton exchange membrane fuel cells. In this study, the titanium mesh was used to replace carbon paper as the cathode gas diffusion layer. In order to avoid the property that titanium is easily oxidized to form a non-conductive titanium dioxide. Therefore, in this study, the titanium mesh was pickled with hydrochloric acid to form a titanium hydride layer with anti-oxidation ability on the surface of the titanium mesh, so as to improve its anti-oxidation ability and current output in the proton exchange membrane fuel cell. In the study, the carbon paper gas diffusion layer of the cathode in the fuel cell membrane electrode group was replaced by titanium meshes with different pore sizes to compare its performance, and then the titanium meshes were acid-washed with hydrochloric acid to improve the antioxidant capacity of the titanium meshes in the fuel cell. The titanium mesh can significantly improve the oxidation resistance of the titanium mesh, avoid the formation of oxides, and reduce the activation resistance of the fuel cell. Compared with the titanium mesh without pickling, the current density of the fuel cell can be increased by 33.6%. The best titanium mesh developed in this research is a 200-mesh titanium mesh pickled with hydrochloric acid. The measured current density is 1782.1 mA/cm2 under operating conditions of 70 oC, 1 atm, and 0.6 V. When operating at 2 atm, The performance can be improved to 2428.1 mA/cm2, which is comparable to that of commercial carbon paper under the same test conditions, confirming the availability of replacing carbon paper as the gas diffusion layer at the cathode end of low temperature proton exchange membrane fuel cells.
