Ionic conductivity of proton exchange membranes

Beattie, Paul; Orfino, Francesco P.; Basura, Vesna I.; Zychowska, Kristi; Ding, Jianfu; Chuy, Carmen; Schmeisser, Jennifer; Holdcroft, Steven

doi:10.1016/s0022-0728(01)00355-2

Cited by 149 publications

(104 citation statements)

References 40 publications

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“…However, the high methanol permeability through the extensively-studied Nafion membrane remains to be a serious obstacle to their widespread application. The high methanol crossover from the anode to the cathode through the membrane not only wastes fuel and decreases the power density, but also reduces the DMFC lifetime [50]. In this section, various membranes based on acid-base interactions, which suppress methanol crossover while offering acceptable proton conductivity and power density, are discussed.…”

Section: Acid-base Membranes For Dmfcsmentioning

confidence: 99%

Novel Blend Membranes Based on Acid-Base Interactions for Fuel Cells

2012

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Fuel cells hold great promise for wide applications in portable, residential, and large-scale power supplies. For low temperature fuel cells, such as the proton exchange membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs), proton-exchange membranes (PEMs) are a key component determining the fuel cells performance. PEMs with high proton conductivity under anhydrous conditions can allow PEMFCs to be operated above 100 °C, enabling use of hydrogen fuels with high-CO contents and improving the electrocatalytic activity. PEMs with high proton conductivity and low methanol crossover are critical for lowering catalyst loadings at the cathode and improving the performance and long-term stability of DMFCs. This review provides a summary of a number of novel acid-base blend membranes consisting of an acidic polymer and a basic compound containing N-heterocycle groups, which are promising for PEMFCs and DMFCs.

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Section: Acid-base Membranes For Dmfcsmentioning

confidence: 99%

Novel Blend Membranes Based on Acid-Base Interactions for Fuel Cells

2012

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“…O uso de eletrólitos sólidos se tornou comum em pilhas a combustível, sobretudo com o desenvolvimento do copolímero Perfluorosulfônico/PTFE estabilizado, produzido pela DuPontTM sob o nome comercial de NAFION® [12]. Outros polímeros também são muito estudados como alternativa para uso como eletrólito sólido [13].…”

Section: Polímeros Sólidos Como Eletrólitounclassified

“…Diversos autores [11,13,15] estudaram a condutividade protônica de certos polímeros, em especial o NAFION®, em função de sua condição de hidratação, usando a técnica de impedância.…”

Section: Condutividade Protônicaunclassified

Preparação e uso de polímeros sólidos como eletrólito em sensores de hidrogênio

Corrêa

Gomes

2013

Matéria (Rio J.)

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A detecção de hidrogênio permeado através de estruturas metálicas é tema de grande relevância, tendo em vista monitorar e controlar os danos que o hidrogênio causa nos metais, em especial o aço. Existem diversas tecnologias aplicadas à montagem destes sensores como, por exemplo, os sensores eletroquímicos.Muito usados em pilhas a combustível, membranas poliméricas vêm sendo empregadas como alternativa ao eletrólito líquido em sensores eletroquímicos por diversas razões, como: resistência à deterioração e durabilidade. Existem diversos tipos que possuem as características para este fim, porém o mais empregado é o Nafion®. A principal característica destes polímeros é sua condutividade protônica causada pela dissociação das moléculas de água presentes em sua estrutura. Sendo assim, a sua condutividade é fortemente dependente da quantidade de água contida no material. A temperatura é outra variável que pode influenciar na condutividade protônica.Foi feita uma revisão destas variáveis e das técnicas que podem ser empregadas na preparação de polímeros para se obter as propriedades desejáveis. A análise inicia com a discussão do método de preparação, limpeza inicial, hidratação e acondicionamento do polímero hidratado. Com este trabalho espera-se obter uma diretriz para a preparação de um polímero para uso como eletrólito sólido, suas características e propriedades e assim, aplicá-lo ao desenvolvimento de um sensor eletroquímico de hidrogênio.Palavras-chave: hidrogênio, sensores, polímeros condutores de prótons, eletrólitos sólidos. ABSTRACTThe permeated hydrogen detection through a metal membrane is essential to monitoring and control of hydrogen damage, especially in steels. Among several sensors technologies available, the electrochemical sensors are widely used.Solid polymer electrolytes (SPE), used in Solid Polymer Electrolyte Fuel Cells (SPEFC), can be an alternative to replace liquid electrolyte in electrochemical sensor, due its chemical and mechanical stability. There are several polymers used in this application, although the standard one is Nafion®. The most important characteristic of a SPE is the proton conductivity, caused by water molecules dissociation in the structure of the polymer. Consequently, the conductivity is highly dependent on membrane humidification conditions. Temperature can also influence the proton conductivity.In this work, we review the SPE characterization and its treatment techniques. We discuss also preparation, hydration and storage of a polymer to be employed in construction of a hydrogen electrochemical sensor.

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“…[9][10][11] The BAM3G membranes have been demonstrated for about 15 000 h of cumulated lifetime in a wide variety of Ballard fuel cell hardware, and their cost has been reduced to $55-160 m À2 . In fuel cell systems, the BAM3G membranes exhibited superior performances to both Nafion and Dow membranes at the current densities above 650 mA cm À2 .…”

Section: Introductionmentioning

confidence: 99%

Degradation mechanism of polystyrene sulfonic acid membrane and application of its composite membranes in fuel cells

Xing

et al. 2002

Phys. Chem. Chem. Phys.

153

100

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The lifetime behavior of a H 2 /O 2 proton exchange membrane (PEM) fuel cell with polystyrene sulfonic acid (PSSA) membrane have been investigated in order to give an insight into the degradation mechanism of the PSSA membrane. The distribution of sulfur concentration in the cross section of the PSSA membrane was measured by energy dispersive analysis of X-ray, and the chemical composition of the PSSA membrane was characterized by infrared spectroscopy before and after the lifetime experiment. The degradation mechanism of the PSSA membrane is postulated as: the oxygen reduction at the cathode proceeds through some peroxide intermediates during the fuel cell operation, and these intermediates have strong oxidative ability and may chemically attack the tertiary hydrogen at the a-carbon of the PSSA; the degradation of the PSSA membrane mainly takes place at the cathode side of the cell, and the loss of the aromatic rings and the SO 3 À groups simultaneously occurs from the PSSA membrane. A new kind of the PSSA-Nafion composite membrane, where the Nafion membrane is bonded with the PSSA membrane and located at the cathode of the cell, was designed to prevent oxidation degradation of the PSSA membrane in fuel cells. The performances of fuel cells with PSSA-Nafion101 and PSSA-recast Nafion composite membranes are demonstrated to be stable after 835 h and 240 h, respectively.

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Ionic conductivity of proton exchange membranes

Cited by 149 publications

References 40 publications

Novel Blend Membranes Based on Acid-Base Interactions for Fuel Cells

Novel Blend Membranes Based on Acid-Base Interactions for Fuel Cells

Preparação e uso de polímeros sólidos como eletrólito em sensores de hidrogênio

Degradation mechanism of polystyrene sulfonic acid membrane and application of its composite membranes in fuel cells

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