scholarly journals Impact of MPL on Temperature Distribution in Single Polymer Electrolyte Fuel Cell with Various Thicknesses of Polymer Electrolyte Membrane

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2499
Author(s):  
Akira Nishimura ◽  
Tatsuya Okado ◽  
Yuya Kojima ◽  
Masafumi Hirota ◽  
Eric Hu
Keyword(s):  
Power Generation ◽  
Fuel Cell ◽  
Temperature Distribution ◽  
Polymer Electrolyte ◽  
Polymer Electrolyte Membrane ◽  
Polymer Electrolyte Fuel Cell ◽  
Electrolyte Membrane ◽  
The Impact ◽  
Plane Temperature ◽  
Power Generation Performance

The impact of micro porous layer (MPL) with various thicknesses of polymer electrolyte membrane (PEM) on heat and mass transfer characteristics, as well as power generation performance of Polymer Electrolyte Fuel Cell (PEFC), is investigated. The in-plane temperature distribution on cathode separator back is also measured by thermocamera. It has been found that the power generation performance is improved by the addition of MPL, especially at higher current density condition irrespective of initial temperature of cell (Tini) and relative humidity condition. However, the improvement is not obvious when the thin PEM (Nafion NRE-211; thickness of 25 μm) is used. The increase in temperature from inlet to outlet without MPL is large compared to that with MPL when using thick PEM, while the difference between without MPL and with MPL is small when using thin PEM. It has been confirmed that the addition of MPL is effective for the improvement of power generation performance of single PEFC operated at higher temperatures than normal. However, the in-plane temperature distribution with MPL is not even.

The Effect of Ionomer Thin Films in Ionomer- and Water-Filled Agglomerate Models

2011 ◽  
Author(s):  
Peter Dobson ◽  
Marc Secanell
Keyword(s):  
Thin Film ◽  
Fuel Cell ◽  
Polymer Electrolyte ◽  
Numerical Models ◽  
Polymer Electrolyte Membrane ◽  
Catalyst Support ◽  
Catalyst Layer ◽  
Polymer Electrolyte Fuel Cell ◽  
Electrolyte Membrane ◽  
Perfluorosulfonated Ionomer

The catalyst layer of a polymer electrolyte fuel cell is commonly represented in mathematical models as an agglomerate structure of carbon catalyst-support particles. There are two prevailing assumptions for the structure of the agglomerates. The first is that the pores are filled with perfluorosulfonated-ionomer (PFSI). The second is that the pores are hydrophilic and are flooded only with liquid water during operation. The objective of this work is to develop numerical models for single water-filled and ionomer-filled agglomerates in a cathode catalyst layer of a polymer electrolyte membrane fuel cell (PEMFC), and investigate the properties of oxygen transport, proton transport, and reaction kinetics. The two models provide different solutions for the distribution of oxygen and protons, and produce a different reaction profile within the agglomerate. Previous numerical water-filled ionomer models in the literature have neglected the effect of the ionomer thin film. Therefore, the results obtained for both ionomer and water-filled models could not be easily compared. In this article, the equations developed relate the assumed structure of the agglomerates to the structure of the catalyst layer (CL). Results compare the effect of the thin film thickness in the two different types of agglomerates and relate the phenomena occurring within the agglomerates to overall catalyst layer performance.

scholarly journals The Dissolution Dilemma for low Pt Loading Polymer Electrolyte Membrane Fuel Cell Catalysts

2020 ◽  
Author(s):  
Daniel John Seale Sandbeck ◽  
Niklas Mørch Secher ◽  
Masanori Inaba ◽  
Jonathan Quinson ◽  
Jakob Ejler Sørensen ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Polymer Electrolyte ◽  
Inductively Coupled Plasma ◽  
Polymer Electrolyte Membrane ◽  
Oxidation States ◽  
Metal Loading ◽  
Electrolyte Membrane ◽  
On Line ◽  
Low Pt Loading ◽  
The Impact

Cost and lifetime currently hinder widespread commercialization of polymer electrolyte<br>membrane fuel cells (PEMFCs). Reduced electrode Pt loadings lower costs; however, the impact<br>of metal loading (on the support) and its relation to degradation (lifetime) remain unclear. The<br>limited research on these parameters stems from synthetic difficulties and lack of in situ<br>analytics. This study addresses these challenges by synthesizing 2D and 3D Pt/C model catalyst<br>systems via two precise routes and systematically varying the loading. Pt dissolution was<br>monitored using on-line inductively coupled plasma mass spectrometry (on-line-ICP-MS), while<br>X-ray spectroscopy techniques were applied to establish the oxidation states of Pt in correlation<br>with metal loading. Dissolution trends emerge which can be explained by three particle<br>proximity dependent mechanisms: (1) shifts in the Nernst dissolution potential, (2) redeposition,<br>and (3) alteration of Pt oxidation states. These results identify engineering limitations, which<br>should be considered by researchers in fuel cell development and related fields. <br>

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