scholarly journals Hybrid Proton-Exchange Membrane Based on Perfluorosulfonated Polymers and Resorcinol–Formaldehyde Hydrogel

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4123
Author(s):  
Alexandra Maria Isabel Trefilov ◽  
Adriana Balan ◽  
Ioan Stamatin
Keyword(s):  
Thermal Stability ◽  
Ionic Conductivity ◽  
Relative Humidity ◽  
Thermo Gravimetric Analysis ◽  
Composite Membranes ◽  
Proton Exchange ◽  
Membrane Electrode ◽  
Gravimetric Analysis ◽  
Resorcinol Formaldehyde ◽  
Exchange Membrane

Organic resorcinol–formaldehyde (RF) hydrogels were introduced into a hybrid cation-exchange membrane in order to enhance its following properties: water uptake, thermal stability, and ionic conductivity. This study was aimed to investigate the modifications induced by the RF organic clusters that form a uniform distributed network within the perflourosulfonated acid (PFSA) matrix. RF concentration was controlled by resorcinol and formaldehyde impregnation time using water or ethanol solvents. The specific morphological and structural properties were characterized by atomic force microscopy, UV–Vis, and Fourier transform infrared spectroscopy. Thermo-gravimetric analysis was employed to study the thermal stability and degradation processes of the composite membranes. Proton conductivity, as a function of relative humidity (RH) at 80 °C, was measured using in-plane four-point characterization technique. Compared to the pristine membrane, the PFSA–RF hybrid membranes showed improved thermal stability at up to 46 °C and higher ionic conductivity for low RF content, especially at low relative humidity, when using ethanol-based solvents. Single fuel cell testing on RF-based membrane–electrode assembly revealed impeccable fuel crossover and power performance at 80 °C and 40% relative humidity, delivering a 76% increase in power density compared to a reference assembled with a pristine membrane and the same catalyst loadings.

Synthesis and Characterization of Poly(ether ketone) Containing Side Sulfonic Acid Group for Proton Exchange Membrane Fuel Cell

2010 ◽  
Vol 658 ◽  
pp. 41-44 ◽  
Author(s):  
Dong Wan Seo ◽  
Young Don Lim ◽  
Soon Ho Lee ◽  
Tae Whan Hong ◽  
Soon Chul Ur ◽  
...  
Keyword(s):  
Proton Exchange Membrane ◽  
Thermo Gravimetric Analysis ◽  
Acid Group ◽  
Proton Exchange ◽  
Valeric Acid ◽  
Gravimetric Analysis ◽  
Co Catalyst ◽  
Ether Ketone ◽  
Exchange Membrane

Poly(ether ketone)s (PEK) containing 25-75 mol % valeric acid were prepared with bisphenol A, 4,4-dichlorobenzophenone and 4,4-Bis(4-hydroxylphenyl)valeric acid using potassium carbonate in DMAc (dimethyl acetami de) at 165 °C. Copolymers containing carboxylacid group were reduced to hydroxy group by BH3 solution 1M in THF and NaBH4 co-catalyst. Sulfonated poly(ether ketone)s (S-PEK) were obtained by reaction of 1,3-propanesultone and the reduced copolymer (PEK-OH) with sodium methoxide. A series of copolymers were studied by 1H-NMR spectroscopy, differential scanning calorimeter (DSC), and thermo gravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymers with water and methanol. The S-PEK membranes exhibited proton conductivities from 1.31  10-3 to 3.52  10-3 S/cm, water swell from 12.70 to 35.50 %, IEC from 0.45 to 0.75 meq/g and methanol diffusion coefficients from 3.65  10-7 to 5.10  10-7 cm2/S at 25 °C.

The Influence of Transient Variations on the Durability of PEM Fuel Cells

2010 ◽  
Author(s):  
Chang-Ching Chen ◽  
Chia-Chi Sung ◽  
Chun-Ting Liao
Keyword(s):  
Ionic Conductivity ◽  
Oxygen Concentration ◽  
Proton Exchange Membrane ◽  
Sudden Change ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Water Flooding ◽  
Membrane Electrode ◽  
Transient Phenomenon ◽  
Exchange Membrane

Recently, a number of studies have shown that the ionic conductivity of a membrane electrode assembly (MEA) strongly depends on the water retention ability of the proton exchange membrane in the fuel cell. This suggests that water management in the cell is important in achieving high PEMFC performance. Therefore, membrane dehydration, water flooding, and cell durability have become major challenges in PEMFC applications. In this study, we investigated the effect of the transient phenomenon on PEMFC performance using an electrode with an area of 25 cm2. Parameters, including the cell temperature, stoichiometry of the fuel/oxidant, relative humidity of the reactive gas, were used for analyzing the performance of PEMFCs, along with fluid field imaging technologies. The results indicated that the ionic conductivity of the proton exchange membrane has a positive effect on PEMFC performance. PEMFC voltage will cause a sudden change in the current density overshoot phenomenon. This is because the decline in oxygen concentration and the oxygen concentration itself are also affected by the water concentration. This study revealed the relationship between the transient phenomenon and the performance of PEMFCs.

Effect of Modified Nanoclay Composite on Blended PVDF/PEG Electrolyte Membranes for Fuel Cell Applications

2018 ◽  
Vol 17 (03) ◽  
pp. 1760042 ◽  
Author(s):  
P. Bahavan Palani ◽  
K. Sainul Abidin ◽  
R. Kannan ◽  
S. Rajashabala
Keyword(s):  
Fuel Cell ◽  
Water Uptake ◽  
Electrochemical Impedance ◽  
Thermo Gravimetric Analysis ◽  
Composite Membranes ◽  
Proton Exchange ◽  
Chromatographic Technique ◽  
Gravimetric Analysis ◽  
Additive Concentration ◽  
Nanocomposite Membranes

This research work describes the fabrication of polymer blend nanocomposite membranes using the solution casting method. These membranes were fabricated with Poly (Vinylidene Fluoride) (PVdF) as host, Poly (Ethylene Glycol) (PEG) in steps of 2[Formula: see text]wt.% as blending polymer and Montmorillonite (MMT) nanoclay particles in steps of 3[Formula: see text]wt.% which were used as received. The protonated MMT was synthesized through an ion exchange process with column chromatographic technique. The prepared membrane’s performance was investigated using different characterization techniques of Thermo Gravimetric Analysis (TGA), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), water uptake, IEC and electrochemical impedance spectroscopy. Thermal stability was decreased while adding PEG into PVDF but it is controlled with the addition of MMT on PVDF/PEG blend matrix. Moreover, It is noticed that, the increase of water uptake, IEC by the increasing additive concentration of PEG and MMT. XRD studies reveal the increased amorphous phase with uniform exfoliation of nanoclay particles. The highest proton conductivity value of 0.127[Formula: see text]S cm[Formula: see text] is obtained with 9[Formula: see text]wt.% of MMT in the PVdF/PEG/MMT composite membranes at room temperature with 100% Relative Humid (RH) condition and 10 V.% of sulfonation. The blended nanocomposite membranes fulfill the requirements of proton exchange membrane for fuel cell application.

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.

Preparation and Characterization of Sulfonated Poly(ether Sulfone) Using 4,4-Bis(4-Hydroxylphenyl)valeric Acid for Proton Exchange Membrane Fuel Cell Application

2009 ◽  
Vol 620-622 ◽  
pp. 73-76 ◽  
Author(s):  
Dong Wan Seo ◽  
Young Don Lim ◽  
M. S. Islam Mollah ◽  
Soon Ho Lee ◽  
Sang Ho Moon ◽  
...  
Keyword(s):  
Proton Exchange Membrane ◽  
Thermo Gravimetric Analysis ◽  
Proton Exchange ◽  
Valeric Acid ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Fuel Cell Application ◽  
Exchange Membrane ◽  
Sulfonated Poly

Poly(ether sulfone)s (PES) containing 25-75 mol % valeric acid were prepared with bisphenol A, bis(4-chlorophenyl)sulfone and 4,4-Bis(4-hydroxylphenyl)valeric acid using potassium carbonate in DMAc (dimethylacetamide) at 160 °C. Copolymers containing carboxylacid group were reduced to hydroxy group by BH3 solution 1M in THF and NaBH4 co-catalyst. Sulfonated poly(ether sulfone)s (S-PES) were obtained by reaction of 1,3-propanesultone and the reduced copolymer (PES-OH) with potassium t-butoxide. A series of copolymers were studied by 1H-NMR spectroscopy, differential scanning calorimetry (DSC), and thermo gravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymers with water and methanol. The S-PES membranes exhibited proton conductivities from 1.20  10-3 to 3.40  10-3 S/cm, water swell from 12.25 to 31.50 %, IEC from 0.43 to 0.72 meq/g and methanol diffusion coefficients from 3.60  10-7 to 4.90  10-7 cm2/S at 25 °C.

scholarly journals Effect of Stratification of Cathode Catalyst Layers on Durability of Proton Exchange Membrane Fuel Cells

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2975
Author(s):  
Zikhona Nondudule ◽  
Jessica Chamier ◽  
Mahabubur Chowdhury
Keyword(s):  
Fuel Cells ◽  
Proton Exchange Membrane ◽  
Electrochemical Impedance ◽  
Catalyst Layer ◽  
Cost Effective ◽  
Proton Exchange ◽  
Membrane Electrode ◽  
Potential Cycling ◽  
Catalyst Layers ◽  
Exchange Membrane

To decrease the cost of fuel cell manufacturing, the amount of platinum (Pt) in the catalyst layer needs to be reduced. In this study, ionomer gradient membrane electrode assemblies (MEAs) were designed to reduce Pt loading without sacrificing performance and lifetime. A two-layer stratification of the cathode was achieved with varying ratios of 28 wt. % ionomer in the inner layer, on the membrane, and 24 wt. % on the outer layer, coated onto the inner layer. To study the MEA performance, the electrochemical surface area (ECSA), polarization curves, and electrochemical impedance spectroscopy (EIS) responses were evaluated under 20, 60, and 100% relative humidity (RH). The stratified MEA Pt loading was reduced by 12% while maintaining commercial equivalent performance. The optimal two-layer design was achieved when the Pt loading ratio between the layers was 1:6 (inner:outer layer). This MEA showed the highest ECSA and performance at 0.65 V with reduced mass transport losses. The integrity of stratified MEAs with lower Pt loading was evaluated with potential cycling and proved more durable than the monolayer MEA equivalent. The higher ionomer loading adjacent to the membrane and the bi-layer interface of the stratified catalyst layer (CL) increased moisture in the cathode CL, decreasing the degradation rate. Using ionomer stratification to decrease the Pt loading in an MEA yielded a better performance compared to the monolayer MEA design. This study, therefore, contributes to the development of more durable, cost-effective MEAs for low-temperature proton exchange membrane fuel cells.

scholarly journals On the Effect of Anion Exchange Ionomer Binders in Bipolar Electrode Membrane Interface Water Electrolysis

2021 ◽  
Author(s):  
Britta Mayerhöfer ◽  
Konrad Ehelebe ◽  
Florian Dominik Speck ◽  
Markus Bierling ◽  
Johannes Bender ◽  
...  
Keyword(s):  
Proton Exchange Membrane ◽  
Water Electrolysis ◽  
Membrane Electrode Assembly ◽  
Proton Exchange ◽  
Membrane Electrode ◽  
Bipolar Electrode ◽  
Electrode Interface ◽  
Exchange Membrane ◽  
Electrode Membrane ◽  
Pem Water Electrolyzer

Bipolar membrane|electrode interface water electrolyzers (BPEMWE) were found to outperform a proton exchange membrane (PEM) water electrolyzer reference in a similar membrane electrode assembly (MEA) design based on individual porous...

Novel Proton Exchange Membrane for High Temperature Fuel Cells

1997 ◽  
Vol 496 ◽  
Author(s):  
M. Bhamidipati ◽  
E. Lazaro ◽  
F. Lyons ◽  
R. S. Morris
Keyword(s):  
Thermal Stability ◽  
Fuel Cells ◽  
High Temperature ◽  
Electrochemical Performance ◽  
Proton Exchange Membrane ◽  
Research Effort ◽  
Analysis Data ◽  
Proton Exchange ◽  
Temperature Conductivity ◽  
Exchange Membrane

ABSTRACTThis research effort sought to demonstrate that combining select phosphonic acid additives with Nafion could improve Nafion's high temperature electrochemical performance. A 1:1 mixture of the additive with Nafion, resulted in a film that demonstrated 30% higher conductivity than a phosphoric acid equilibrated Nafion control at 175°C. This improvement to the high temperature conductivity of the proton exchange membrane Nafion is without precedent. In addition, thermal analysis data of the test films suggested that the additives did not compromise the thermal stability of Nafion. The results suggest that the improved Nafion proton exchange membranes could offer superior electrochemical performance, but would retain the same degree of thermal stability as Nafion. This research could eventually lead to portable fuel cells that could oxidize unrefined hydrocarbon fuels, resulting in wider proliferation of fuel cells for portable power.

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