Synthesis and Characterization of Sulfonated Polyimide Based Membranes for Proton Exchange Membrane Fuel Cells

2013 ◽  
Vol 10 (4) ◽  
Author(s):  
Sabit Adanur ◽  
Hai Zheng
Keyword(s):  
Fuel Cells ◽  
Proton Exchange Membrane ◽  
Mechanical Stability ◽  
Exchange Capacity ◽  
Proton Exchange ◽  
Membrane Electrode ◽  
Scanning Calorimetry ◽  
Hydrogen Flow ◽  
Sulfonated Polyimide ◽  
Exchange Membrane

Sulfonated polyimide (SPI) based membranes for proton exchange membrane fuel cells (PEMFC) have been synthesized by using a one-step high temperature polymerization method. The membranes were characterized with Fourier transform infrared spectra (FTIR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC); water uptake, ion-exchange capacity, proton conductivity and mechanical stability were tested. The results showed that the membranes had good thermal and mechanical stability and exhibited good performance when they were assembled into membrane electrode assemblies (MEAs). Fuel cell testing was performed. The SPI copolymer based MEA was tested under different hydrogen flow rates to compare with the commercially available Nafion® based MEA.

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.

Highly stable nanostructured membrane electrode assembly based on Pt/Nb2O5nanobelts with reduced platinum loading for proton exchange membrane fuel cells

Nanoscale ◽  
2017 ◽  
Vol 9 (20) ◽  
pp. 6910-6919 ◽  
Author(s):  
Yachao Zeng ◽  
Xiaoqian Guo ◽  
Zhiqiang Wang ◽  
Jiangtao Geng ◽  
Hongjie Zhang ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Proton Exchange Membrane ◽  
Membrane Electrode Assembly ◽  
Proton Exchange ◽  
Membrane Electrode ◽  
Exchange Membrane ◽  
Platinum Loading

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.

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