MODELS OF THE THERMODYNAMIC AND KINETIC BEHAVIOR OF FUEL CELLS AND THEIR USE IN THE RATIONAL DESIGN OF FUEL CELL ELECTRODES

2005 ◽  
Vol 14 (14) ◽  
pp. 529-576
Author(s):  
Ernest G. Cravalho ◽  
Fritz Pierre, Jr.
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Rational Design ◽  
Kinetic Behavior ◽  
Fuel Cell Electrodes

Spontaneous penetration of hydrogen and oxygen through semihydrophobic fuel cell electrodes

1983 ◽  
Vol 48 (2) ◽  
pp. 560-567
Author(s):  
Karel Smrček ◽  
Olga Marholová ◽  
Karel Micka
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Qualitative Agreement ◽  
New Method ◽  
Theoretical Studies ◽  
Fuel Cell Electrodes ◽  
Oxygen Fuel

Spontaneous penetration of hydrogen or oxygen through porous Teflon membranes into water or KOH solution was studied by a new method based on the measurement of the minimum gas overpressure necessary for the penetration at various temperatures. The results were compared with measurements on hydrogen-oxygen fuel cells and are in qualitative agreement with theoretical studies. The penetration of gases into the electrolyte can be prevented by their humidification before introducing them into the cells.

Highly durable fuel cell electrodes based on ionomers dispersed in glycerol

2014 ◽  
Vol 16 (13) ◽  
pp. 5927-5932 ◽  
Author(s):  
Y. S. Kim ◽  
C. F. Welch ◽  
N. H. Mack ◽  
R. P. Hjelm ◽  
E. B. Orler ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Polymer Electrolyte ◽  
Polymer Electrolyte Membrane ◽  
Fuel Cell Electrodes ◽  
Electrolyte Membrane ◽  
Dispersing Medium

A major, unprecedented improvement in the durability of polymer electrolyte membrane fuel cells is obtained by tuning the properties of the interface between the catalyst and the ionomer by choosing the appropriate dispersing medium.

scholarly journals Protonated Phosphonic Acid Electrodes for High Power Heavy-Duty Vehicle Fuel Cells

2021 ◽  
Author(s):  
Katie Lim ◽  
Albert Lee ◽  
Vladimir Atanasov ◽  
Jochen Kerres ◽  
Santosh Adhikari ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Phosphonic Acid ◽  
Heavy Duty ◽  
Perfluorosulfonic Acid ◽  
Phosphonic Acids ◽  
Fuel Cell Electrodes ◽  
Fuel Cell Performance ◽  
Heavy Duty Vehicle ◽  
Anhydrous Proton Conduction

Abstract Fuel cells operating at above 100 °C under anhydrous conditions provide an ideal solution for the heat rejection problem of heavy-duty vehicle applications. Here, we report protonated phosphonic acid electrodes that remarkably improve fuel cell performance. The protonated phosphonic acids are comprised of tetrafluorostyrene phosphonic acid and perfluorosulfonic acid polymers in which a proton of the perfluorosulfonic acid is transferred to the phosphonic acid to enhance the anhydrous proton conduction of fuel cell electrodes. By implementing this material into fuel cell electrodes, we obtained a fuel cell exhibiting a rated power density of 780 milliwatts per square centimeter at 160 °C, with minimal degradation during 2,500 hours of operation, and 700 thermal cycles from 40 to 160 °C under load.

Analogies Between Fuel Cells and Heat Exchangers: From Phenomena to Design Principles

2003 ◽  
Author(s):  
Comas Haynes ◽  
William Rooker ◽  
Vaughn Melbourne ◽  
Jeffery Jones
Keyword(s):  
Fuel Cells ◽  
Heat Exchanger ◽  
Fuel Cell ◽  
Heat Exchangers ◽  
Series Resistance ◽  
Active Regions ◽  
Fuel Cell Electrodes ◽  
Heat Exchanger Design ◽  
Optimal Area ◽  
In Transit

Fuel cells and heat exchangers have numerous similarities. Both technologies are used to produce an “energy-in-transit.” Heat exchangers foster thermal transport (heat) as a result of thermal potential differences between streams; fuel cells foster charge transport across electrodes (current leading to power) as a result of electrochemical/electric potential differences between the reactant streams and fuel cell electrodes. Additional analogs include series resistance formulations, active regions for transport phenomena and pertinent capacity rates. These similarities have motivated the extension of heat exchanger design philosophies to fuel cells development. Pilot simulations have been done wherein solid oxide fuel cell geometries and process settings are being optimized via electrochemical pinch points, electroactive area optimization (patterned after optimal area allocation within heat exchangers), electrode “fins” for diminished polarization, and electrochemical multi-staging (motivated by heat exchanger network concepts). The prevailing theme has been to bridge methodologies from the mature field of heat exchanger design to improve fuel cell design practices.

Advancing Fuel Cells Technology via Analogous Heat Exchanger Design Principles

2002 ◽  
Author(s):  
Comas Haynes ◽  
Vaughn Melbourne ◽  
William Rooker
Keyword(s):  
Fuel Cells ◽  
Heat Exchanger ◽  
Fuel Cell ◽  
Heat Exchangers ◽  
Series Resistance ◽  
Active Regions ◽  
Fuel Cell Electrodes ◽  
Heat Exchanger Design ◽  
Area Optimization ◽  
In Transit

Fuel cells and heat exchangers have numerous similarities. Both technologies are used to produce an “energy-in-transit.” Heat exchangers foster thermal transport (heat) as a result of thermal potential differences between streams; fuel cells foster charge transport across electrodes (current leading to power) as a result of electrochemical/electric potential differences between the reactant streams and fuel cell electrodes. Additional analogs include series resistance formulations, active regions for transport phenomena and pertinent capacity rates. These similarities have motivated the extension of heat exchanger design philosophies to fuel cells development. Pilot simulations have been done wherein solid oxide fuel cell geometries and process settings are being optimized via electrochemical pinch points, electroactive area optimization (patterned after optimal UA allocation within heat exchangers), and electrode “fins” for diminished polarization. The prevailing theme has been to bridge methodologies from the mature field of heat exchanger design to improve fuel cell design practices.

Highly proton conductive membranes based on carboxylated cellulose nanofibres and their performance in proton exchange membrane fuel cells

2019 ◽  
Author(s):  
Valentina Guccini ◽  
Annika Carlson ◽  
Shun Yu ◽  
Göran Lindbergh ◽  
Rakel Wreland Lindström ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Surface Charge ◽  
Proton Exchange Membrane ◽  
Membrane Surface ◽  
Proton Exchange ◽  
Membrane Thickness ◽  
Fuel Cell Performance ◽  
Cellulose Nanofibres ◽  
Exchange Membrane

The performance of thin carboxylated cellulose nanofiber-based (CNF) membranes as proton exchange membranes in fuel cells has been measured in-situ as a function of CNF surface charge density (600 and 1550 µmol g<sup>-1</sup>), counterion (H<sup>+</sup>or Na<sup>+</sup>), membrane thickness and fuel cell relative humidity (RH 55 to 95 %). The structural evolution of the membranes as a function of RH as measured by Small Angle X-ray scattering shows that water channels are formed only above 75 % RH. The amount of absorbed water was shown to depend on the membrane surface charge and counter ions (Na<sup>+</sup>or H<sup>+</sup>). The high affinity of CNF for water and the high aspect ratio of the nanofibers, together with a well-defined and homogenous membrane structure, ensures a proton conductivity exceeding 1 mS cm<sup>-1</sup>at 30 °C between 65 and 95 % RH. This is two orders of magnitude larger than previously reported values for cellulose materials and only one order of magnitude lower than Nafion 212. Moreover, the CNF membranes are characterized by a lower hydrogen crossover than Nafion, despite being ≈ 30 % thinner. Thanks to their environmental compatibility and promising fuel cell performance the CNF membranes should be considered for new generation proton exchange membrane fuel cells.<br>

Employment Effects of Hydrogen and Fuel Cells: Phase 1 Report, Fuel Cell Electric Vehicles

2018 ◽  
Author(s):  
Marianne Mintz ◽  
Catherine Mertes ◽  
Eric Stewart ◽  
Stephanie Burr
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Electric Vehicles ◽  
Phase 1 ◽  
Employment Effects ◽  
Fuel Cell Electric Vehicles
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