Synthesis and properties of a new fluorine‐containing polybenzimidazole for high‐temperature fuel‐cell applications

Chuang, Shih-Wei; Hsu, Steve Lien‐Chung

doi:10.1002/pola.21555

Cited by 125 publications

(101 citation statements)

References 18 publications

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“…Based on the hexafluoro PBI (F 6 -PBI, see Scheme 5i) [99,100] and dodecylamine (DOA)-modified montmorillonite (MMT) [176], Chuang et al [100] prepared nanocomposite membranes, showing reduced coefficient of thermal expansion, reduced methanol crossover, and much decreased plasticizing effect of the phosphoric acid after acid doping.…”

Section: Composite Membranesmentioning

confidence: 99%

“…Membranes by direct casting of the polymer solution in polyphosphoric acid showed much higher conductivity than the corresponding para-PBI membranes. Using 4,4-(hexafluoroisopropylidene)bis(benzoic acid) [70,99,100], hexafluoro PBI (F 6 -PBI, Scheme 5i) has been prepared, showing good organosolubility. Similarly PBI containing tert-butyl groups (tert-butyl PBI, Scheme 5j) has also been prepared from 5-tert-butyl isophthalic acid [70].…”

Section: 134mentioning

confidence: 99%

See 1 more Smart Citation

High temperature proton exchange membranes based on polybenzimidazoles for fuel cells

Jensen

Savinell

et al. 2009

Progress in Polymer Science

1,235

852

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This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. To achieve high temperature operation of proton exchange membrane fuel cells (PEMFC), preferably under ambient pressure, acid-base polymer membranes represent an effective approach. The phosphoric acid-doped polybenzimidazole membrane seems so far the most successful system in the field. It has in recent years motivated extensive research activities with great progress. This treatise is devoted to updating the development, covering polymer synthesis, membrane casting, physicochemical characterizations and fuel cell technologies. To optimize the membrane properties, high molecular weight polymers with synthetically modified or N-substituted structures have been synthesized. Techniques for membrane casting from organic solutions and directly from acid solutions have been developed. Ionic and covalent cross-linking as well as inorganic-organic composites has been explored. Membrane characterizations have been made including spectroscopy, water uptake and acid doping, thermal and oxidative stability, conductivity, electro-osmotic water drag, methanol crossover, solubility and permeability of gases, and oxygen reduction kinetics. Related fuel cell technologies such as electrode and MEA fabrication have been developed and high temperature PEMFC has been successfully demonstrated at temperatures of up to 200• C under ambient pressure. No gas humidification is mandatory, which enables the elimination of the complicated humidification system, compared with Nafion cells. Other operating features of the PBI cell include easy control of air flow rate, cell temperature and cooling. The PBI cell operating at above 150• C can tolerate up to 1% CO and 10 ppm SO 2 in the fuel stream, allowing for simplification of the fuel processing system and possible integration of the fuel cell stack with fuel processing units. Long-term durability with a degradation rate of 5 V h −1 has been achieved under continuous operation with hydrogen and air at 150-160• C. With load or thermal cycling, a performance loss of 300 V per cycle or 40 V h −1 per operating hour was observed. Further improvement should be done by, e.g. optimizing the thermal and chemical stability of the polymer, acid-base interaction and acid management, activity and stability of catalyst and more importantly the catalyst support, as well as the integral interface between electrode and membrane.

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Section: Composite Membranesmentioning

confidence: 99%

Section: 134mentioning

confidence: 99%

High temperature proton exchange membranes based on polybenzimidazoles for fuel cells

Jensen

Savinell

et al. 2009

Progress in Polymer Science

1,235

852

View full text Add to dashboard Cite

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“…Pu et al [197] have prepared and tested N-methyl (PNMBI) and N-ethyl (PNEBI) derivates of PBI, and Chuan and Hsu [198] reported fluorine-containing PBI. A number of PBI membranes modified by ionic or covalent cross-linking and composite PBI membranes have been reviewed by Li et al [199].…”

Section: Polybenzoimidazolesmentioning

confidence: 98%

“…Several authors have determined methanol permeability for PBI [12,192,197,280,413], methyl and ethyl-PBI [197], and fluorinated PBI [198,414], for different acid doping degree. The reported permeability coefficients are summarized in Fig.…”

Section: Acid Doped Pbi Membranesmentioning

confidence: 99%

Membranes for Direct Alcohol Fuel Cells

Corti

2013

Direct Alcohol Fuel Cells

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This chapter is devoted to summarize and discuss the main properties of ionomeric membranes used in direct alcohol PEM fuel cells. Although Nafion is the proton exchange membrane commonly used in methanol and other direct alcohol fuel cells, other proton and alkaline membranes are being investigated in order to improve the efficiency of DAFC. The goals in the development of this critical component of DAFC are: low cost, long durability, low alcohol permeability and high electrical conductivity. The last two properties can be combined in a single parameter, the membrane selectivity that accounts for the ratio between the proton and alcohol transport through the membrane. This parameter can be compared to that measured for Nafion to define a relative selectivity, which is a primary parameter to evaluate the potentiality of a ionomer material to be used in alcohol feed fuel cells.The vast catalogue of polymeric materials reviewed here included Nafion composite with inorganic and organic fillers, and non-fluorinated proton conducting membranes such as sulfonated polyimides, poly(arylene ether)s, polysulfones, poly (vinyl alcohol), polystyrenes, and acid-doped polybenzimidazoles. Anionexchange membranes are also discussed because of the facile electro-oxidation of alcohols in alkaline media and because of the minimization of alcohol crossover in alkaline direct alcohol fuel cells.The performance of different types of membranes in direct alcohol fuel cells, mainly methanol, are summarized and discussed in order to identify the most promissory ones. The lack of correlation between the relative selectivity and fuel cell performance of the membranes indicates that the architecture of the three

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“…Thus, PBI containing ether group, 2 azo groups, 3 amide groups, 4 fluorine groups, 5 pyridine and imidazole groups, 6 cardo (fluorene) groups, 7 sulfone linkages, 8 thiaxanthone groups, 9 aliphatic groups, 10,11 alicyclic structures, 12 dibenzothiophene and dioxodibenzothiophene units, 13 adamantine units, 14 benzofurobenzofuran structures, 15 and phenoxaphosphine 16 have been reported. PBIs, containing functional groups such as sulfonic acid, cyano, hydroxy, and nitro groups have also been reported in literature.…”

Section: Introductionmentioning

confidence: 97%

Nitrophenoxy groups containing polybenzimidazoles as polymer electrolytes for fuel cells: Synthesis and characterization

Kulkarni

Potrekar

Kulkarni

et al. 2010

J of Applied Polymer Sci

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Polybenzimidazoles containing different contents of pendant nitrophenoxy groups were prepared by condensation of 3,3 0 -diamino-benzidine with a mixture of 3,5-dicarboxyl-4 0 -nitro diphenyl ether and isophthalic acid (IPA) in different ratios in polyphosphoric acid. The polymers are soluble in polar aprotic solvents, they have inherent viscosities in the range of 0.75-1.10 dL g À1 and they form tough and transparent films on solution casting. They have good thermal stability with initial decomposition temperature ranging from 380 to 416 C in nitrogen, good tensile strength ranging from 56 to 65 MPa and reasonably good oxidative stability. Phosphoric acid uptake of these polymers is low compared with PBI and membranes doped with phosphoric acid exhibit good proton conductivity in the range of 6.6Â 10 À3 to 1.9Â 10 À2 S/cm at 25 C and 1.2Â 10 À2 to 4.9Â 10 À2 S/cm at 175 C, compared with 3.9Â 10 À3 S/cm at 25 C and 3.2Â 10 À2 S/cm at 175 C for PBI. These membranes are suitable for applications as polymer electrolyte for fuel cell and presumably for gas separation at high temperature.

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Synthesis and properties of a new fluorine‐containing polybenzimidazole for high‐temperature fuel‐cell applications

Cited by 125 publications

References 18 publications

High temperature proton exchange membranes based on polybenzimidazoles for fuel cells

High temperature proton exchange membranes based on polybenzimidazoles for fuel cells

Membranes for Direct Alcohol Fuel Cells

Nitrophenoxy groups containing polybenzimidazoles as polymer electrolytes for fuel cells: Synthesis and characterization

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