高温浸渍法PBI／H3PO4复合膜特性及电池性能研究

Study of high temperature acid-doping PBI/H_3PO_4 composite membrane characteristic and its fuel cell performance

以国产3,3'-二氨基联苯胺和间苯二甲酸为单体,合成了具有良好溶解性的聚苯并咪唑(PBI)树脂。通过红外和核磁共振表征证实了聚苯并咪唑的结构。溶液浇铸法制备了PBI膜,并利用高温浸渍法制备了PBI/H3PO4复合膜,考察了浸渍温度对膜特性的影响。相对于室温浸泡,高温浸泡磷酸降低了复合膜的初始水含量,有利于提高膜中酸含量,从而提高电池性能。采用PBI作为粘结剂、聚偏氟乙烯(PVDF)作为憎水剂、Pt/C为催化剂制备了催化层,通过优化催化层中各组分配比制备了膜电极,并采用无增湿氢气和氧气对膜电极性能进行了测试,在表压0.2MPa、150℃的条件下,电池最大功率密度达到1.537W/cm2。

Poly [2,2＇-m- （phenylene）-5,5＇-bibenzimidazole] （PBI） was synthesized via homegrown monomer 3, 3＇-diaminobenzidine （DAB） and isophthalic acid （IPA）, which had good solubility in polar solvents. The structure of the PBI resin was validated by FTIR and 1H NMR. The PBI membrane was prepared by solvent casting method, and the PBI/H3PO4 composite membrane was prepared by high temperature acid doping method. The influence of doping temperature on membrane characteristic was studied. Compared to room temperature phosphoric acid doping, high temperature acid doping was beneficial for reducing the initial water content and increasing the acid content of the composite membrane. Using PBI as binder, PVDF as hydrophobic agent, and Pt/C as catalyst, catalyst layer was prepared based on the optimization of the electrode components. The fuel cell performance was tested with dry hydrogen and oxygen under the gauge pressure of 0.2 MPa and the operating temperature of 150℃, and the maximum power density reached 1.537 W/cm2.