Polarity governed selective amplification of through plane proton shuttling in proton exchange membrane fuel cells

2017 ◽  
Vol 19 (11) ◽  
pp. 7751-7759 ◽  
Author(s):  
Manu Gautam ◽  
Mruthyunjayachari Chattanahalli Devendrachari ◽  
Ravikumar Thimmappa ◽  
Alagar Raja Kottaichamy ◽  
Shahid Pottachola Shafi ◽  
...  

Polarity governed amplification of fuel cell performance in graphene oxide-based proton exchange membrane fuel cells.

2020 ◽  
Vol 261 ◽  
pp. 114277 ◽  
Author(s):  
Likun Wang ◽  
Stoyan Bliznakov ◽  
Rebecca Isseroff ◽  
Yuchen Zhou ◽  
Xianghao Zuo ◽  
...  

Author(s):  
Y. Zhou ◽  
G. Lin ◽  
A. J. Shih ◽  
S. J. Hu

Proton exchange membrane (PEM) fuel cells are favored in many applications due to their simplicity and relatively high power density. However, there has been a lack of understandings of the fundamental mechanisms of assembly and manufacturing induced phenomena and their influence on performance and durability. This paper presents a comprehensive analysis of assembly pressure induced phenomena in PEM fuel cells using multi-physics based modeling. A finite-element-based structural and mass-transfer model was developed by integrating mechanical deformation, mass transfer resistance, and electrical contact resistance to study the effects of assembly pressure and the fuel cell overall performance. Contact resistance, inhomogeneous deformation of membrane and GDL, electrochemical analysis were simulated. The fuel cell performance was predicted and an optimal assembly pressure was identified through this multi-physics model. Results show that PEM fuel cell performance first increases gradually to a maximum and then decreases with further assembly pressure increase. The influence of temperature and humidity on cell performance was also investigated.


2019 ◽  
Author(s):  
Valentina Guccini ◽  
Annika Carlson ◽  
Shun Yu ◽  
Göran Lindbergh ◽  
Rakel Wreland Lindström ◽  
...  

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>


2021 ◽  
Vol 514 ◽  
pp. 230574
Author(s):  
Yannick Garsany ◽  
Robert W. Atkinson ◽  
Benjamin D. Gould ◽  
Rachel Martin ◽  
Laetitia Dubau ◽  
...  

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