Sensitivity Analysis of the Impedance Characteristics of Proton Exchange Membrane Fuel Cells

Fuel Cells ◽  
2016 ◽  
Vol 16 (5) ◽  
pp. 547-556 ◽  
Author(s):  
S. M. Rezaei Niya ◽  
R. K. Phillips ◽  
M. Hoorfar
Keyword(s):  
Sensitivity Analysis ◽  
Fuel Cells ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Impedance Characteristics ◽  
Exchange Membrane

scholarly journals Sensitivity Based Order Reduction of a Chemical Membrane Degradation Model for Low-Temperature Proton Exchange Membrane Fuel Cells

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5611
Author(s):  
Ambrož Kregar ◽  
Philipp Frühwirt ◽  
Daniel Ritzberger ◽  
Stefan Jakubek ◽  
Tomaž Katrašnik ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Low Temperature ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Chemical Degradation ◽  
Membrane Degradation ◽  
Radical Species ◽  
Exchange Membrane

The chemical degradation of the perfluorinated sulfonic acid (PFSA) ion-exchange membrane as a result of an attack from a radical species, originating as a by-product of the oxygen reduction reaction, represents a significant limiting factor in a wider adoption of low-temperature proton exchange membrane fuel cells (LT-PEMFCs). The efficient mathematical modeling of these processes is therefore a crucial step in the further development of proton exchange membrane fuel cells. Starting with an extensive kinetic modeling framework, describing the whole range of chemical processes leading to the membrane degradation, we use the mathematical method of sensitivity analysis to systematically reduce the number of both chemical species and reactions needed to efficiently and accurately describe the chemical degradation of the membrane. The analysis suggests the elimination of chemical reactions among the radical species, which is supported by the physicochemical consideration of the modeled reactions, while the degradation of Nafion backbone can be significantly simplified by lumping several individual species concentrations. The resulting reduced model features only 12 species coupled by 8 chemical reactions, compared to 19 species coupled by 23 reactions in the original model. The time complexity of the model, analyzed on the basis of its stiffness, however, is not significantly improved in the process. Nevertheless, the significant reduction in the model system size and number of parameters represents an important step in the development of a computationally efficient coupled model of various fuel cell degradation processes. Additionally, the demonstrated application of sensitivity analysis method shows a great potential for further use in the optimization of models of operation and degradation of fuel cell components.

Dependency of the Power of the Constant Phase Element to Operating Conditions in Proton Exchange Membrane Fuel Cells

2015 ◽  
Author(s):  
Seyed Mohammad Rezaei Niya ◽  
Ryan Phillips ◽  
Mina Hoorfar
Keyword(s):  
Fuel Cells ◽  
Proton Exchange Membrane ◽  
Constant Phase Element ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Impedance Characteristics ◽  
Different Temperatures ◽  
Current Densities ◽  
Constant Phase Elements ◽  
Exchange Membrane

Despite the numerous studies conducted on the constant phase element (CPE) characteristics, they are not fully understood yet. In this paper, the constant phase element required for modeling the impedance characteristics of the proton exchange membrane fuel cells are studied in different operating conditions. The impedance of the cell is measured in different temperatures, anode and cathode relative humidities and potentials (current densities). Then, the powers of the constant phase elements required for modeling the most dominant arc in the measured Nyquist plots are determined, and the values are compared in different operating conditions using the analysis of variance method. It is shown that the CPE power is not related to the temperature and relative humidities; while it changes slightly when the potential or current density changes.

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>

Latest Trends and Challenges In Proton Exchange Membrane Fuel Cell (PEMFC)

2017 ◽  
Vol 10 (1) ◽  
pp. 96-105 ◽  
Author(s):  
Mohammed Jourdani ◽  
Hamid Mounir ◽  
Abdellatif El Marjani
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Total Cost ◽  
Cell Efficiency ◽  
Technical Advances ◽  
Exchange Membrane

Background: During last few years, the proton exchange membrane fuel cells (PEMFCs) underwent a huge development. Method: The different contributions to the design, the material of all components and the efficiencies are analyzed. Result: Many technical advances are introduced to increase the PEMFC fuel cell efficiency and lifetime for transportation, stationary and portable utilization. Conclusion: By the last years, the total cost of this system is decreasing. However, the remaining challenges that need to be overcome mean that it will be several years before full commercialization can take place.This paper gives an overview of the recent advancements in the development of Proton Exchange Membrane Fuel cells and remaining challenges of PEMFC.

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