scholarly journals Tension-Torsion Fatigue Tests on the proton Exchange membrane Nafion 115, used in fuel cells

2021 ◽  
Vol 2 (5) ◽  
pp. 6840-6849
Author(s):  
Gonzalo Mariano Domínguez Almaraz ◽  
Luis Miguel Torres Duarte ◽  
Christian Jesús Torres Pacheco
Keyword(s):  
Fuel Cells ◽  
Relative Humidity ◽  
Polymeric Material ◽  
Torsion Angle ◽  
Proton Exchange Membrane ◽  
Fatigue Loading ◽  
Fatigue Tests ◽  
Proton Exchange ◽  
Exchange Membrane ◽  
Fatigue Endurance

Fatigue tests under tension-torsion have been carried out on the membrane Nafion 115 (Perfluorosulfonic acid, PFSA). This polymeric material is a main component to construct fuel cells, used as proton exchange membrane. These membranes undergo mechanical loading of tension and torsion during its industrial life. A self-designed machine has been constructed to obtain the fatigue endurance on this polymeric material under tension-torsion and the following conditions: one magnitude for the torsion angle, five initial tensile stresses, room temperature, and environmental relative humidity, and frequency of 1.6 Hz. The experimental results show that fatigue endurance decreases with the increase of tensile stress when the torsion angle remains constant, as well as temperature and relative humidity (both taken at environmental conditions). Fracture surfaces were analyzed by SEM, in order to investigate the principal trends of crack initiation and propagation under this modality of fatigue loading.   Se han realizado ensayos de fatiga bajo tensión-torsión en la membrana Nafion 115 (ácido perfluorosulfónico, PFSA). Este material polimérico es un componente principal para la construcción de pilas de combustible, utilizado como membrana de intercambio de protones. Estas membranas se someten a cargas mecánicas de tensión y torsión durante su vida industrial. Se ha construido una máquina de diseño propio para obtener la resistencia a la fatiga de este material polimérico bajo tensión-torsión y en las siguientes condiciones: una magnitud para el ángulo de torsión, cinco tensiones iniciales de tracción, temperatura ambiente y humedad relativa ambiental, y frecuencia de 1,6 Hz. Los resultados experimentales muestran que la resistencia a la fatiga disminuye con el aumento de la tensión de tracción cuando el ángulo de torsión se mantiene constante, así como la temperatura y la humedad relativa (ambas tomadas en condiciones ambientales). Las superficies de fractura fueron analizadas por SEM, con el fin de investigar las principales tendencias de iniciación y propagación de grietas bajo esta modalidad de carga de fatiga.

scholarly journals Ameliorated Performance of Sulfonated Poly(Arylene Ether Sulfone) Block Copolymers with Increased Hydrophilic Oligomer Ratio in Proton-Exchange Membrane Fuel Cells Operating at 80% Relative Humidity

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1871 ◽  
Author(s):  
Ae Kim ◽  
Mohanraj Vinothkannan ◽  
Kyu Lee ◽  
Ji Chu ◽  
Sumg Ryu ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Relative Humidity ◽  
Proton Conductivity ◽  
Proton Exchange Membrane ◽  
Exchange Capacity ◽  
Proton Exchange ◽  
Arylene Ether ◽  
Poly Condensation ◽  
Exchange Membrane ◽  
Sulfonated Poly

We designed and synthesized a series of sulfonated poly(arylene ether sulfone) (SPES) with different hydrophilic or hydrophobic oligomer ratios using poly-condensation strategy. Afterward, we fabricated the corresponding membranes via a solution-casting approach. We verified the SPES membrane chemical structure using nuclear magnetic resonance (1H NMR) and confirmed the resulting oligomer ratio. Field-emission scanning electron microscope (FE-SEM) and atomic force microscope (AFM) results revealed that we effectively attained phase separation of the SPES membrane along with an increased hydrophilic oligomer ratio. Thermal stability, glass transition temperature (Tg) and membrane elongation increased with the ratio of hydrophilic oligomers. SPES membranes with higher hydrophilic oligomer ratios exhibited superior water uptake, ion-exchange capacity, contact angle and water sorption, while retaining reasonable swelling degree. The proton conductivity results showed that SPES containing higher amounts of hydrophilic oligomers provided a 74.7 mS cm−1 proton conductivity at 90 °C, which is better than other SPES membranes, but slightly lower than that of Nafion-117 membrane. When integrating SPES membranes with proton-exchange membrane fuel cells (PEMFCs) at 60 °C and 80% relative humidity (RH), the PEMFC power density exhibited a similar increment-pattern like proton conductivity pattern.

Perfluorosulfonyl Imide versus Perfluorosulfonic Acid Ionomers in Proton‐Exchange Membrane Fuel Cells at Low Relative Humidity

ChemSusChem ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 590-600 ◽  
Author(s):  
Huu‐Dat Nguyen ◽  
Regis Porihel ◽  
Jean‐Blaise Brubach ◽  
Emilie Planes ◽  
Priscillia Soudant ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Relative Humidity ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Perfluorosulfonic Acid ◽  
Exchange Membrane

scholarly journals Patterned Membranes for Proton Exchange Membrane Fuel Cells Working at Low Humidity

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1976
Author(s):  
Oliver Fernihough ◽  
Holly Cheshire ◽  
Jean-Michel Romano ◽  
Ahmed Ibrahim ◽  
Ahmad El-Kharouf ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Relative Humidity ◽  
Proton Exchange Membrane ◽  
Active Surface ◽  
Proton Exchange ◽  
Cathode Side ◽  
Membrane Electrode ◽  
Active Surface Area ◽  
Power Performance ◽  
Exchange Membrane

High performing proton exchange membrane fuel cells (PEMFCs) that can operate at low relative humidity is a continuing technical challenge for PEMFC developers. In this work, micro-patterned membranes are demonstrated at the cathode side by solution casting techniques using stainless steel moulds with laser-imposed periodic surface structures (LIPSS). Three types of patterns, lotus, lines, and sharklet, are investigated for their influence on the PEMFC power performance at varying humidity conditions. The experimental results show that the cathode electrolyte pattern, in all cases, enhances the fuel cell power performance at 100% relative humidity (RH). However, only the sharklet pattern exhibits a significant improvement at 25% RH, where a peak power density of 450 mW cm−2 is recorded compared with 150 mW cm−2 of the conventional flat membrane. The improvements are explored based on high-frequency resistance, electrochemically active surface area (ECSA), and hydrogen crossover by in situ membrane electrode assembly (MEA) testing.

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