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Polymer Membranes for Fuel Cells (PEMFCs). Jack Edelbrock Alexandera Kolberg Timothy Lam Ross Nanopoulos Stacy Yeh. Key Points . History Applications Chemistry Properties of PEM. PEM Materials Problems Future Goals.
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Polymer Membranes for Fuel Cells (PEMFCs) Jack Edelbrock Alexandera Kolberg Timothy Lam Ross Nanopoulos Stacy Yeh
Key Points History Applications Chemistry Properties of PEM PEM Materials Problems Future Goals
INTRODUCTION • What is a fuel cell? • Converts chemical energy into DC electricity • Why the interest? • Clean • Alternative to oil • Efficient http://www.thehydrogencompany.com/Hydrogen-Fuel-Cells/20W---1kW-Systems/21/H-200-PEM-FC-System-(200W).htm
B. Smitha, S. Sridhar, A.A. Khan. Solid polymer electrolyte membranes for fuel cell applications – a review. J. Membrane Sci. 259 (2005) 10-26.
Applications Automobiles Homes/Businesses Small Electronics The Space Program
HISTORY • First developed in 1960 • Oil crisis in late 1960s • The Gemini Space Program • Development of Nafion by DuPont in 1970 • Ballard's use of stacked fuel cells in 1990 Viswanathan, B. (2007). Fuel cells: Principles and applications. (pp. 272-275). Taylor and Francis.
Fuel Cell Mechanisms PEMFC: F. Barbir. PEM Fuel Cells. Elsevier. (2005) 28
Purpose of PEM • Electrolyte • Must conduct protons • Must block electrons • Barrier • Impermeable to gas • Separates reduction and oxidation reactions Fuel Cell Membrane from Mirko Antloga, Chemical Engineering Department, Case Western Reserve University Photo taken by: Alexandera Kolberg
Material Selection Criteria Material Properties • High proton conductivity • Mechanical strength and stability • Chemical and electrochemical stability • Thermal stability • Low oxygen and hydrogen gas permeability Other Factors to Consider: • Hydration • Thickness
Polymer Membrane Materials Hickner, M. (2004). Alternative polymer systems for proton exchange membranes (pems). Chemical Review, 104, 4587-4612. • Perfluorinated polymers • Nafion • Sulfonated hydrocarbons • SPEEK Mikhailenko, S. (2004). Proton conducting membranes based on cross-linked sulfonated poly(ether ether ketone) (speek). Journal of Membrane Science,233, 93-99.
Nafion Kreuer, K. D. (2001). On the development of proton conducting polymer membranes for hydrogen and methanol fuel cells. Journal of Membrane Science,185, 29-39. Xiao-Zi, Y. (2012). Degradation of a PEM fuel cell stack with nafion membranes of different thicknesses. Part II: Exsitu diagnosis. (205 ed., pp. 324-334). Journal of Power Sources.
SPEEK Kreuer, K. D. (2001). On the development of proton conducting polymer membranes for hydrogen and methanol fuel cells. Journal of Membrane Science,185, 29-39. Mikhailenko, S. (2004). Proton conducting membranes based on cross-linked sulfonated poly(ether ether ketone) (speek). Journal of Membrane Science,233, 93-99.
Water Management • Key in performance • In low temperatures, high humidity needed • Increased proton conductivity with higher water uptake1 • Excess leads to membrane swelling • Effects on water level • Contamination by foreign ions • Membrane thickness • Temperature 1. Bose, S., Kuila, T., Nguyen, T. X. H., Kim, N. H., Lau, K. T., & Lee, J. H. (2011). Polymer membranes for high temperature proton exchange membrane fuel cell: Recent advances and challenges. Progress in Polymer Science, 36(6), 813-843. 2. Okada, T. (1999). Theory for water management in membranes for polymer electrolyte fuel cells. Journal of Electroanalytical Chemistry, 465(1), 18-29.
Contamination by Impurities (CO) • Fuel in PEMFC’s must be quite pure • Contamination causes performance loss • Competition in reactions • Blocking active ion exchange site Baschuk, J. J., & Li, X. (2001). Carbon monoxide poisoning of proton exchange membrane fuel cells. International Journal of Energy Research, 25(8), 695-713.
Voltage in Relation to CO Baschuk, J. J., & Li, X. (2001). Carbon monoxide poisoning of proton exchange membrane fuel cells. International Journal of Energy Research, 25(8), 695-713.
Future • Water Management Solutions • Ionic content1 • Thickness • SiO2, TiO21 • Humidification • Silicon oxide2 1. Gubler, L. (2010). Trends for fuel cell membrane development. Desalination, 250, 1034-1037. 2. Zaidi, S. M. J. (2009). Research trends in polymer electrolyte membranes for pemfc. Springer.
Future • Cost • Processing • SPEEK1 • Hyflon2 • High Temperature • H3PO4 doped PBI2 1. Zaidi, S. M. J. (2009). Research trends in polymer electrolyte membranes for pemfc. Springer. 2. Wang, Y., Chen, K. S., & Mishler, J. (2011). A review of polymer electrolyte membrane fuel cells: Technology, applications, and needs on fundamental research. Applied Energy, 88, 981-1007. http://en.wikipedia.org/wiki/File:PolybenzimidPhOester.png
Goals (2015) • Obstacles