Membrane high-temperature PEMs

Dr. Hui has worked on various projects, including chemical sensors, solid oxide fuel cells, magnetic materials, gas separation membranes, nanostruc-tured materials, thin film fabrication, and protective coatings for metals. He has more than 80 research publications, one worldwide patent, and one U.S. patent (pending). He is currently leading and involved in several projects for the development of metal-supported solid oxide fuel cells (SOFCs), ceramic nanomaterials as catalyst supports for high-temperature PEM fuel cells, protective ceramic coatings on metallic substrates, ceramic electrode materials for batteries, and ceramic proton conductors. Dr. Hui is also an active member of the Electrochemical Society and the American Ceramic Society. 

There is increasing interest in preparing Ti02 nanomembranes both for advanced photocatalytic processes in the field of air and water purification, purification of drinking water, novel membrane for high temperature PEM fuel cells,Li-ion batteries,advanced nanoelectrode arrays (NEA) and nanofiltration and pervaporation. ... 

Figure 3.14. Percentage of cell individual voltage drop caused by charger transfer, membrane, and mass transfer resistances at different current densities and 80°C [21]. (Reproduced by permission of ECS—The Electrochemical Society, from Tang Y, Zhang J, Song C, Liu H, Zhang J, Wang H, Mackinnon S, Peckham T, Li J, McDermid S, Kozak P. Temperature dependent performance and in situ AC impedance of high-temperature PEM fuel cells using the Nafion-112 membrane.)...

Numerous works have reported the decrease of hydrated Nafion conductivity at high temperature. Thus, Rikukawa and Sanui [325] observed a maximum in the conductivity of Nafion 115 around 80 °C, and a sudden drop at temperatures above 100 °C. Aric6 et al. [315] also observed a maximum conductivity around 120 °C, as shown in Fig. 6.20, for recast Nafion membranes. This behavior is the consequence of membrane dehydration at temperatures above 100 °C, which limits the use of Nafion in high temperature PEM fuel cells. 

Asensio JA, Smchez EM, G6mez-Romero P (2010) Proton-conducting membranes based on benzimidazole polymers for high-temperature PEM fuel cells. A chemical quest. Chem Soc Rev 39 3210-3239... 

Krishnan P, Park JS, Kim CS (2006) Performance of a poly(2,5-baizimidazole) membrane based high temperature PEM fuel cell in the presence of carbon mmoxide. J Power Sources... 

Coordination polymers containing rotaxane linkers 12CSR5896. Design and synthesis of cross-Hnked poly(benzoxazine)- and polybenzimidazole-based copolymer membranes and their application to an electrolyte membrane for a high-temperature PEM fuel cell 13P77. 

Proton Exchange Membrane Fuel Cells—a selection of PEM fuel cell review paper on various key components and analysis techniques. High temperature PEM fuel cells are also included. 

There have been studies indicating that blends of PBI polymers with pyridine-containing polymers could prove useful in a high-temperature PEM fuel cell. Kallitsis et al. [31] combined commercially supplied w-PBI with an aromatic polyether that contained a pyridine moiety in the main chain (PPyPO) these polymer blends were then soaked in 85% wt PA. Dynamic mechanical analysis of a 75/25 PBl/PPyPO block copolymer showed reasonable mechanical strength and flexibility. The conductivity of this copolymer was not reported, but the conductivity of 85/15 PBI/PPyPO block copolymer was 0.013 S cm at a relatively low PA doping level. Further investigation of these systems is required to prove its utility as a fuel cell membrane. 

Harris TAL, Walczyk D (2006) Development of a casting technique for membrane material used in high-temperature PEM fuel cells. J Manuf Processes 8(1) 19-31... 

BASF Fuel Cell GmbH (2010) Celtec MEAs membrane electrode assemblies for high temperature PEM fuel cells, http //www.basf-fuelcell.com/en/projects/celtec-mea.html... 

Nowadays, common membranes adopted in PEM fuel cell are based on Nation (N212, N115, N117 etc.) however, as discussed above, several alternative PSFA membranes with shorter pendant side chain have been developed [29]. Despite the good performance under conventional operating conditions (60-80 °C), most of them are not suitable for high-temperature PEM fuel cell applications, especially if they are operated at temperatures above 1(X) °C. It is well... 

Pefkianakis EK, Deimede V, Daletou MK et al (2005) Novel polymer electrolyte membrane, containing pyridine and tetramethyl biphenyl units, for application in high temperature PEM fuel cells. Macromoi Rapid Commun 26 1724-1728... 

In the early years, extensive work was carried out to synthetically modify PBI derivatives using different chemical structures of the monomers, i.e., different tetraamine and dicarboxylic acid derivatives, as comprehensively reviewed by Neuse et al. [2]. Since the mPBI membrane was successfully demonstrated as the membrane electrolyte in high temperature PEM fuel cells, much effort has been devoted to the synthesis of various novel PBI derivatives in order to improve the physicochemical properties of the membranes and their durability in fuel cells [9, 10]. This section summarizes the recent synthetic efforts on PBI structure analogues, primarily for applications in the high temperature PEM fuel cells. Table 7.1 lists the chemical structures of PBI variants with modified main chains. 

Steenberg T, Hjuler HA, Terkelsen C et al (2012) Roll-to-roll coated PBI membranes for high temperature PEM fuel cells. Energy Environ Sci 5 6076-6080... 

Voyiatzis GA (2005) Spectroelectrochemical investigation of the ability of PBI-based membranes to be acid doped. Paper presented at symposium on high temperature PEM fuel cells, Rio, Patras, Greece, 13-14 Sept 2005... 

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