Polybenzimidazole fuel cell membranes

Xiao, L. et al., High-temperature polybenzimidazole fuel cell membranes via a sol-gel process, Chem. Mater., 17, 5328, 2005. 

L. Xiao, H. Zhang, E. Scanlon, L.S. Ram-anathan, E.W. Choe, D. Rogers, T. Apple, B.C. Benicewicz, High-temperature polybenzimidazole fuel cell membranes via a sol-gel process, Chem. Mater. 17 (21) (2005) 5328-5333. 

Xiao, L., Zhang, H., Scanlon, E., Ramanathan, L. S., Choe, E.-W., Rogers, D., Apple, T., and Benicewicz, B. (2005b) High-temperature polybenzimidazole fuel cell membranes via a sol-gel process. Chemical Materials 17, 5328-5333. 

Lixiang, X. Zhang, H. Choe, E.-W. Scanlon, E. Ramanathan, L.S. Benicewicz, B.C. Synthesis and characterization of pyridine-based polybenzimidazoles as novel fuel cell membrane materials. Fuel Chem. Div. Prepr. 2003, 48, 447. 

As shown in Fig. 14, PIM-1 and PIM-7 have been found to exhibit substantially higher O /Nj selectivities (a(O2/N2)>3.0) than other polymers of similar permeability [41]. Other thermally rearranged [78] polyimides show excellent CO /CH separation selectivities. These materials were also shown to function as fuel cell membranes when doped with H3PO4 and proton conductivities of 0.15 S cm" were observed at 130°C [78] that is, higher than polybenzimidazole membranes. 

Wycisk R, Chisholm J, Lee J, Lin J, Pintauro PN (2006) Direct methanol fuel cell membranes from Nafion-polybenzimidazole blends. J Power Sources 163 9-17... 

Poly(2,5-benzmiidazole) or ABPBI, is another polybenzimidazole derivative that has been investigated as an alternative fuel cell membrane material. ABPBI can result from the polymerization of a single monomer (3,4-diaminobenzoic acid, DABA) in polyphosphoric acid (Fig. 5) or in P2O5-MSA mixture. The... 

J.R.P. Jayakody, S.H. Chung, L. Durantino, H. Zhang, L. Xiao, B.C. Benicewicz, NMR studies of mass transport in high-acid-content fuel cell membranes based on phosphoric acid and polybenzimidazole, J. Electrochem. Soc. 154 (2) (2007) B242-B246. 

Other fuel cell membrane materials include modified polybenzimidazole. In the US researchers have developed rod-coil block copolyimides which exhibit high levels of ionic conduction and which can be made into dimensionally stable solid electrolyte fuel cell membranes. These membrane materials are also suitable for use in lithinm-ion electrochemical cells. 

Kerres et al., among others, developed the acid-base blend membranes from sulfonated polymers and aminated or other basic polymers [98] and concluded that the protonation of the basic groups is incomplete if the base is too weak [99]. Very recently, Frutsaert et al. [70] synthesized novel polymers for the development of high temperature PEMFC membranes comprising a blend of s-PEEK and a fluorinated copolymer bearing imidazole functions as pendant groups. The extensive work on intermediate temperature fuel cell membranes are well reviewed in Chap. 4 of this book including polybenzimidazole as the basic component and sulfonated and phosphonated ionomers of either nonfluorinated or partially fluorinated backbones as the acidic component. 

Sinigersky V, Budurova D, Penchev H et al (2013) Polybenzimidazole-graft-polyvinylphosphonic acid proton-conducting fuel cell membranes. J Appl Poiym Sci 129 1223-1231... 

Kim TH, Lim TW, Lee JC (2007) High-temperature fuel cell membranes based on mechanically stable para-ordered polybenzimidazole prepared by direct casting. J Power Sources 172 172-179... 

Since the polymers to be activated need to have at least one acidic proton in the main chain and must be soluble in suitable solvents, the number of polymers which can be modified by this particular method is limited. So far only the modification of poly(arylene ether sulfone)s and polybenzimidazoles as suitable materials for fuel cell membranes has been reported in the literature [4,5,32,102,136-146,148-151]. The attempt to lithiate poly(ether sulfone) under homogeneous conditions failed so far, due to poor solubility and the alternating electron-donating and electron-withdrawing linkages present in poly(ether sulfone), which result in an overall unfavorable balance in the polymer chain. 

Besides the covalent crosslinking, Kerres et al. investigated the properties of fuel cell membranes of ionicaUy crosslinked polysulfonic adds. This type of crosslinking was achieved by blending sulfonated poly(arylene ether sul-fone)s and poly(arylene ether ketone)s with basic polymers, such as polybenzimidazole, poly(ethylene imine), poly(vinyl pyridine), or amino functional-... 

Abstract This chapter reviews the progress towards applying acid-doped polybenzimidazoles (PBls) as polymer electrolyte membrane (PEM) fuel cell membranes over... 

Poly(2,5-benzimidazole), or AB-PBI, (Fig. 1) is another polybenzimidazole derivative that has been investigated as an alternative fuel cell membrane material. AB-PBI is synthesized from 3,4-diaminobenzoic acid (DABA), a relatively inexpensive and widely available monomer. Discussions on AB-PBI and comparisons to other PBIs must be done with some caution. The repeat unit of AB-PBI contains a single benzimidazole moiety, while the repeat unit of PBIs made from TAB contain two benzimidazoles. If one assume the acid-base interactions are important for membrane properties, then this difference is important. For clarification in this chapter, the polymer acid ratio for AB-PBI will be expressed as moles phosphoric acid per moles benzimidazole moiety (moles PA/BI). Doubling this value will provide an estimate for the TAB-based PBI equivalent loading levels. 

Acid-Doped Polybenzimidazole Phosphoric-acid-doped polybenzimidazole (PBI see Fig. 29.8a) fuel cell membranes were developed some 13 years ago at Case Western Reserve University (Wainright et al., 1995). Researchers found that a significant amount of phosphoric acid could be absorbed into a PBI film without scarifying the mechanical strength of the membrane. The sorbed acid species conduct protons in the absence of... 

Sinigersky, V., Budurova, D., Penchev, H., Ublekov, R, and Radev, 1. (2013) Polybenzimidazole-graft-polyvinylphosphonic acid—Proton conducting fuel cell membranes, J. Appl. Polym. Sci., 129, 1223-1231. 

Benicewicz, B. C., Yu, S., Xiao, L. and Perry, K. 2007. Advances in polybenzimidazole (PBI) membrane materials. In Advances in materials for proton exchange membrane fuel cell systems, Pacific Grove, CA, Feb. 18-21. 

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