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Polybenzimidazole/inorganic composite membrane with advanced performance for high temperature polymer electrolyte membrane fuel cells
Author(s) -
Seo Kwangwon,
Seo Jongchul,
Nam KiHo,
Han Haksoo
Publication year - 2017
Publication title -
polymer composites
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.577
H-Index - 82
eISSN - 1548-0569
pISSN - 0272-8397
DOI - 10.1002/pc.23563
Subject(s) - membrane , materials science , phosphoric acid , conductivity , scanning electron microscope , polymer , electrolyte , fourier transform infrared spectroscopy , ultimate tensile strength , proton exchange membrane fuel cell , thermogravimetric analysis , chemical engineering , doping , diffractometer , composite material , analytical chemistry (journal) , polymer chemistry , chromatography , chemistry , electrode , biochemistry , optoelectronics , engineering , metallurgy
In this work, Al–Si was synthesized via a sol–gel process and introduced in poly 2,2′‐ m ‐(phenylene)‐5,5′‐bibenzimidazole (PBI). As a result, a series of five Al–Si/PBI composite (ASPBI) membranes (0, 3, 6, 9, and 12 wt%) were developed and characterized for application in high temperature polymer electrolyte membrane fuel cells (HT‐PEMFCs). The chemical and morphological structure of ASPBI membranes were analyzed by Fourier transform infrared spectroscopy, X‐ray diffractometer, and scanning electron microscopy. According to the doping level test and thermogravimetric analysis, as the concentration of Al–Si increased, the doping level increased up to 475% due to the affinity and interaction between Al and phosphoric acid (PA). Moreover, the proton conductivity, current density at 0.6 V, and maximum power density of ASPBI membranes increased up to 0.31 S cm −1 , 0.320 A cm −2 , and 0.370 W cm −2 , respectively, because the increased concentration of Al–Si allows the membranes to hold more PA. Alternatively, as the amount of Al–Si increased, the tensile strength of PA‐doped and ‐undoped membranes decreased. This was caused by both excess PA and aggregation, which can cause serious degradation of the membrane and induce cracks. Furthermore, the PA‐doped and ‐undoped ASPBI12 had the lowest tensile strength of 11.6 and 77.2 MPa. The improved proton conductivity and single cell performance of ASPBI membranes implies that these membranes are possible candidates for HT‐PEMFC applications. However, further studies seeking to enhance the compatibility between PBI and Al–Si and optimize the amount of filler should be performed. POLYM. COMPOS., 38:87–95, 2017. © 2015 Society of Plastics Engineers