Phosphoric acid distribution in the membrane electrode assembly of high temperature proton exchange membrane fuel cells

2009 ◽  
Vol 54 (26) ◽  
pp. 6570-6575 ◽  
Author(s):  
Kyungjung Kwon ◽  
Jung Ock Park ◽  
Duck Young Yoo ◽  
Jung S. Yi
Author(s):  
Hsiu-Li Lin ◽  
Chih-Ren Hu ◽  
Po-Hao Su ◽  
Yu-Cheng Chou ◽  
Che-Yu Lin

Phosphoric acid doped poly(benzimidazole) (PBI) is one of excellent candidates of proton exchange membranes for high temperature (150–180°C) proton exchange membrane fuel cells (PEMFCs). However, the strong inter-polymer hydrogen bonds cause low elongation and brittleness of PBI membranes. In this work, we synthesize poly(benzimidazole) (PBI) and butylsulfonated poly(benzimidazole) (PBI-BS), in which around 22 mole% of imidazole –NH groups of PBI are grafted with sulfonated butyl groups. We show the elongation, phosphoric acid doping level, and proton conductivity of PBI can be improved by blending ∼ 20 wt% of PBI-BS in the PBI membrane, and the membrane electrode assembly prepared from PBI/PBI-BS (8/2 by wt) blend membrane has a better PEMFC performance at 140°C ∼ 180°C than that prepared from PBI membrane. It is believed that the crosslink interactions of imidazole -NH and -N=C-groups with side chain –C4H8−SO3H groups of PBI-BS reduces the inter-PBI hydrogen bonds and increases the free volume of polymers, which leads to the enhancements of the membrane toughness and phosphoric acid doping level and the PEMFC performance.


Nanoscale ◽  
2017 ◽  
Vol 9 (20) ◽  
pp. 6910-6919 ◽  
Author(s):  
Yachao Zeng ◽  
Xiaoqian Guo ◽  
Zhiqiang Wang ◽  
Jiangtao Geng ◽  
Hongjie Zhang ◽  
...  

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