Low-humidity proton exchange membrane fuel

C.H. Park, C.H. Lee, M.D. Guiver, Y.M. Lee, Sulfonated hydrocarbon membranes for medium-temperature and low-humidity proton exchange membrane fuel cells (PEMFCs). Progress in Polymer Science 2011, 36(11), 1443-1498. 

Lee, H.-S., Roy, A., Lane, O., McGrath, J. E., Synthesis and characterization of poly(arylene ether sulfone)-h-polybenzrtnidazole copolymers for high temperature low humidity proton exchange membrane fuel cells. Polymer 2008,49,5387—5396. 

Chao, W. K., Lee, C. M., Tsai, D. C., Chou, C. C., Hsueh, K. L., and Shieu, F. S. Improvement of the proton exchange membrane fuel cell (PFMFC) performance at low-humidity conditions by adding hygroscopic y-Al203 particles into the catalyst layer. Journal of Power Sources 2008 185 136-142. 

A. M. Kannan, L. Cindrella, and L. Munukutla. Functionally graded nanopo-rous gas diffusion layer for proton exchange membrane fuel cells under low relative humidity conditions. Electrochimica Acta 53 (2008) 2416-2422. 

Kreuer KD (2005) Choosing the protogenic groups in PEMS for high temperature, low humidity operation. Conference on advances in materials for proton exchange membrane fuel ceU systems. Pacific Grove, 20-23 Feb 2005... 

A major goal of the research in proton exchange membrane fuel cells is the development of high-temperature membranes that may operate at 120 °C and low humidity. One route are multi-block copolymers with completely disulfonated PAES and naphthalene polyimide oligomers [107]. 

Proton Exchange Membrane Fuel Cells High-Temperature, Low-Humidity Operation... 

High-temperature proton exchange membrane fuel cells (HT-PEM fuel cells), which use modified perfluorosulfonic acid (PFSA) polymers [1—3] or acid-base polymers as membranes [4—8], usually operate at temperatures from 90 to 200 °C with low or no humidity. The development of HT-PEM fuel cells has been pursued worldwide to solve some of the problems associated with current low-temperature PEM fuel cells (LT-PEM fuel cells, usually operated at <90 °C) these include sluggish electrode kinetics, low tolerance for contaminants (e.g. carbon monoxide (CO)), and complicated water and heat management [4,5]. However, operating a PEM fuel cell at >90 °C also accelerates degradation of the fuel cell components, especially the membranes and electrocatalysts [8]. 

There are two major challenges for membrane scientists with regard to proton exchange membrane fuel cells (1) PEMEC membranes that conduct protons under high-temperature and low-humidity conditions and (2) DMFC membranes that are highly conductive but act as barriers to methanol. 

Good mechanical properties of the membranes are one of the necessary requirements for their effective nse in proton exchange membrane fuel cell (PEMFC) applications. The membranes require a tensile stress at a maximum load over 20 MPa and elongation at break over 20% in a low humidity with the general trend of a lower maximum stress for the higher lEC. 

Discover and develop proton exchange membranes (PEMs) capable of extended fuel cell operation at higher temperatures of 120 to 150°C, at low relative humidity (RH), and without leachable components... 

The BPSH block copolymer membranes performed much better as proton exchange membranes for fuel cells than the random copolymers with similar lEC, especially in terms of proton conductivity at low humidity (on the order of mS/cm at 80 °C and 30 % RH, lEC =1.5 meq/g). 

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