Properties, degradation and high temperature fuel cell test of different types of PBI and PBI blend membranes

Li, Qingfeng; Rudbeck, Hans Christian; Chromik, Andreas; Jensen, Jens Oluf; Pan, Chao; Steenberg, Thomas; Calverley, Martin J.; Bjerrum, Niels; Kerres, Jochen

doi:10.1016/j.memsci.2009.10.032

Cited by 208 publications

(105 citation statements)

References 48 publications

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“…136 After the Fenton test, a bimodal molecular weight distribution curve was obtained for polybenzimidazoles containing -SO 2 -and -C(CF 3 ) 2 -functional groups, which suggest a midpoint chain scission mechanism, while a monomodal molecular weight distribution was obtained in the case of pure PBI which is indicative of a degradation mechanism starting from the chain ends. 136 While electron withdrawing groups decrease the electron density of the adjacent aromatic rings and thus decrease their sensitivity towards radicals attack, the introduction of heteroatom groups confers an additional weakness. The formation of blend membranes, and thus physical interaction between polymer chains, is another way that has been shown to preserve membrane integrity by limiting the elution of low molecular weight compounds resulting from the degradation.…”

Section: Durabilitymentioning

confidence: 93%

“…Li et al 136 demonstrated that the presence of strongly electron withdrawing groups introduced into polybenzimidazoles increases their oxidative stability; indeed radicals predominantly attack electron-rich aromatic compounds. 136 After the Fenton test, a bimodal molecular weight distribution curve was obtained for polybenzimidazoles containing -SO 2 -and -C(CF 3 ) 2 -functional groups, which suggest a midpoint chain scission mechanism, while a monomodal molecular weight distribution was obtained in the case of pure PBI which is indicative of a degradation mechanism starting from the chain ends. 136 While electron withdrawing groups decrease the electron density of the adjacent aromatic rings and thus decrease their sensitivity towards radicals attack, the introduction of heteroatom groups confers an additional weakness.…”

Section: Durabilitymentioning

confidence: 99%

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Hydrocarbon proton conducting polymers for fuel cell catalyst layers

Péron

Shi

Holdcroft

2011

Energy Environ. Sci.

101

115

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Proton exchange membrane fuel cells (PEMFCs) employing proton conducting membranes are promising power sources for automotive applications. Perfluorosulfonic acid (PFSA) ionomer represents the state-of-the-art polymer used in both the membrane and catalyst layer to facilitate the transport of protons. However, PFSA ionomer is recognized as having significant drawbacks for largescale commercialization, which include the high cost of synthesis and use of fluorine-based chemistry. According to published research much effort has been directed to the synthesis and study of non-PFSA electrolyte membranes, commonly referred to as hydrocarbon membranes, which has led to optimism that the less expensive proton conducting membranes will be available in the not-so-distant future. Equally important, however, is the replacement of PFSA ionomer in the catalyst layer, but in contrast to membranes, studies of catalyst layers that incorporate a hydrocarbon polyelectrolyte are relatively sparse and have not been reviewed in the open literature; despite the knowledge that hydrocarbon polyelectrolytes in the catalyst layer generally lead to a decrease in electrochemical fuel cell kinetics and mass transport. This review highlights the role of the solid polymer electrolyte in catalyst layers on pertinent parameters associated with fuel cell performance, and focuses on the effect of replacing perfluorosulfonic acid ionomer with hydrocarbon polyelectrolytes. Collectively, this review aims to provide a better understanding of factors that have hindered the transition from PFSA to non-PFSA based catalyst layers.

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Section: Durabilitymentioning

confidence: 93%

Section: Durabilitymentioning

confidence: 99%

Hydrocarbon proton conducting polymers for fuel cell catalyst layers

Péron

Shi

Holdcroft

2011

Energy Environ. Sci.

101

115

View full text Add to dashboard Cite

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“…More recently, Gupta et al [50] have prepared crosslinked membranes based on SPEEK in the presence of varying amounts of PEG and cyclohexane dimethanol (CDM) ( Table 4; 14). PEG is more flexible and hydrophilic than CDM, so this structural difference is reflected clearly in the finer morphology of the network produced, the enhanced storage modulus, the glass transition temperature and the proton conductivity.…”

Section: Crosslinked Poly (Ethylene Glycol) Based Membranesmentioning

confidence: 99%

“…Sulfonated or phosphonated polybenzimidazoles (PBI) [14][15][16], polybenzoxazoles (PBO) [17,18] and polybenzothiazoles (PBT) [19,20] have also been investigated for possible use as PEMs. Nevertheless, there are still unresolved application issues with these membranes due variously to low proton conductivity under low humidity conditions, and poor stability during long-term operation.…”

Section: Introductionmentioning

confidence: 99%

Water Soluble Polymers as Proton Exchange Membranes for Fuel Cells

2012

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Abstract:The relentless increase in the demand for useable power from energy-hungry economies continues to drive energy-material related research. Fuel cells, as a future potential power source that provide clean-at-the-point-of-use power offer many advantages such as high efficiency, high energy density, quiet operation, and environmental friendliness. Critical to the operation of the fuel cell is the proton exchange membrane (polymer electrolyte membrane) responsible for internal proton transport from the anode to the cathode. PEMs have the following requirements: high protonic conductivity, low electronic conductivity, impermeability to fuel gas or liquid, good mechanical toughness in both the dry and hydrated states, and high oxidative and hydrolytic stability in the actual fuel cell environment. Water soluble polymers represent an immensely diverse class of polymers. In this comprehensive review the initial focus is on those members of this group that have attracted publication interest, principally: chitosan, poly (ethylene glycol), poly (vinyl alcohol), poly (vinylpyrrolidone), poly (2-acrylamido-2-methyl-1-propanesulfonic acid) and poly (styrene sulfonic acid). The paper then considers in detail the relationship of structure to functionality in the context of polymer blends and polymer based networks together with the effects of membrane crosslinking on IPN and semi IPN architectures. This is followed by a review of pore-filling and other impregnation approaches. Throughout the paper detailed numerical results are given for comparison to today's state-of-the-art Nafion ® based materials.

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“…[1] At intermediate-T fuel cell membranes, the polymeric base (in most cases a chemically stable polymer from the class of polybenzimidazoles (PBI)) is mixed with a minor amount of a sulfonated or phosphonated polymer where the sulfonated polymer acts as acidic macromolecular ionical crosslinker for the basic polymer, which improves the mechanical and chemical stability of the membrane markedly, compared to the pure basic polymer. [2] In the last step the base-excess blend membrane is doped with phosphoric acid which acts as the proton-conductor in the membrane in an intermediate-T fuel cell (T=100-220°C). In this contribution the acid-base concept is extended to anion-exchange membranes (AEM).…”

Section: Jochen Kerres (University Of Stuttgart) Bmentioning

confidence: 99%

International experts meet in Germany to discuss trends in anion exchange membranes

Germer¹

2014

Fuel Cells Bulletin

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Ion exchange membranes are used in various applications like fuel cells, electrolyzers, or batteries. During the last years, alkaline anion exchange membranes attracted more and more attention. Very promising is their application in fuel cells due to the fact that less cost intensive non-noble metal catalysts can be employed in alkaline environment. Therefore, alkaline membranes and their applications were the main topic of the "Workshop on Ion Exchange Membrane Applications", which was held in Bad Zwischenahn (Germany) on June 17 th -18 th 2014.19 talks were given by membrane specialists from academic research facilities and professionals from producing industry. Besides the scientific agenda, the social program and excursion to the NEXT ENERGY laboratories were well used for establishing and cultivating contacts between researchers and industrial representatives.The workshop was organized by the NEXT ENERGY -EWE Research Centre for Energy Technology (Germany) in collaboration with the Korea Institute of Science and Technology -KIST (South Korea) and the Jagiellonian University of Krakow (Poland). "Due to the success of the first two events we already started to plan the follow up event for 2015. We like to establish a sequel of annual events that will keep the focus on anion exchange membranes to promote their application," stated Dr. Dirk Henkensmeier (KIST, South Korea), co-organizer of the event.The next "Workshop on Ion Exchange Membranes for Energy Applications" (EMEA2015) will take place in Bad Zwischenahn, Germany, on June 22 nd -24 th 2015. Detailed information will be published on www.next-energy.de/EMEA2015.html in the near future. In order to give an impression of the program of the past workshop, this feature article presents four excerpts of the scientific talks by courtesy of the respectively named authors.

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Properties, degradation and high temperature fuel cell test of different types of PBI and PBI blend membranes

Cited by 208 publications

References 48 publications

Hydrocarbon proton conducting polymers for fuel cell catalyst layers

Hydrocarbon proton conducting polymers for fuel cell catalyst layers

Water Soluble Polymers as Proton Exchange Membranes for Fuel Cells

International experts meet in Germany to discuss trends in anion exchange membranes

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