Understanding of Nafion Membrane Additive Behaviors in Proton Exchange Membrane Fuel Cell Conditioning

2018 ◽  
Vol 16 (1) ◽  
Author(s):  
Nana Zhao ◽  
Zhong Xie ◽  
Zhiqing Shi
Keyword(s):  
Fuel Cell ◽  
Large Scale ◽  
Proton Exchange Membrane ◽  
Electrochemical Impedance ◽  
Proton Exchange ◽  
Membrane Electrode ◽  
Production Volume ◽  
Transfer Resistance ◽  
Conditioning Process ◽  
Exchange Membrane

Durability and cost are the two major factors limiting the large-scale implementation of fuel cell technology for use in commercial, residential, or transportation applications. The conditioning cost is usually negligible for making proton exchange membrane fuel cells (PEMFCs) at R&D or demo stage with several tens of stacks each year. However, with industry's focus shifting from component development to commercial high-volume manufacturing, the conditioning process requires significant additional capital investments and operating costs, thus becomes one of the bottlenecks for PEMFC manufacturing, particularly at a high production volume (>1000 stack/year). To understand the mechanisms behind PEMFC conditioning, and to potentially reduce conditioning time or even to eliminate the conditioning process, the conditioning behaviors of commercial Nafion™ XL100 and Nafion® NRE 211 membranes were studied. The potential effects of the membrane additive on fuel cell conditioning were diagnosed using in situ electrochemical impedance spectroscopy (EIS). It was found that the membrane additive led to the significant variation of the charge transfer resistance in EIS during conditioning, which affected the conditioning behavior of the membrane electrode assembly (MEA).

Fabrication of Support Tubular Proton Exchange Membrane For Fuel Cell

2006 ◽  
Vol 4 (4) ◽  
pp. 520-524 ◽  
Author(s):  
Ru-Jun Yu ◽  
Guang-Yi Cao ◽  
Xiu-Qing Liu ◽  
Zhong-Fang Li ◽  
Wei Xing ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Power Density ◽  
Proton Exchange Membrane ◽  
Electrochemical Impedance ◽  
Porous Silica ◽  
Membrane Electrode Assembly ◽  
Proton Exchange ◽  
Membrane Electrode ◽  
Direct Methanol ◽  
Exchange Membrane

The support tubular proton exchange membranes (STPEMs) were fabricated successfully by impregnating porous silica pipe into a solution of perfluorinated resin. The structures of the inner, outer, and cross section of support PEM tube were characterized intensively by scanning electron microscopy observation. In addition, the conductivity and impermeability were measured by electrochemical impedance spectroscopy (EIS) and the bubble method, respectively. Results show that the conductivity of the PEM can reach as low as 1.46S∕m when using the silica pipe of 0.7mm wall thickness. Subsequently, the ST membrane electrode assembly for direct methanol fuel cell (DMFC) and proton exchange membrane fuel cell (PEMFC) applications was prepared first by loading Pt∕C and Pt–Ru∕C catalyst ink onto the outer and inner surfaces of the PEM tube, respectively. The performances of the tubular DMFC and the PEMFC were tested on a self-made apparatus, which shows that the power density of tubular DMFC can reach 10mWcm−2 when 4molL−1 methanol solution flows through the anode at 80°C, and that the power density of tubular PEMFC can reach up to 60mWcm−2 when hydrogen flows at the rates of 20mlmin−1 through the anode at 60°C, both the cathodes adopting air-breathing mode.

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 Pore-Filled Proton-Exchange Membranes with Fluorinated Moiety for Fuel Cell Application

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4433
Author(s):  
Hyeon-Bee Song ◽  
Jong-Hyeok Park ◽  
Jin-Soo Park ◽  
Moon-Sung Kang
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Continuous Process ◽  
Oxidation Stability ◽  
Proton Exchange Membranes ◽  
Proton Exchange ◽  
Cross Linking ◽  
Polymer Backbone ◽  
Transfer Resistance ◽  
Exchange Membrane

Proton-exchange membrane fuel cells (PEMFCs) are the heart of promising hydrogen-fueled electric vehicles, and should lower their price and further improve durability. Therefore, it is necessary to enhance the performances of the proton-exchange membrane (PEM), which is a key component of a PEMFC. In this study, novel pore-filled proton-exchange membranes (PFPEMs) were developed, in which a partially fluorinated ionomer with high cross-linking density is combined with a porous polytetrafluoroethylene (PTFE) substrate. By using a thin and tough porous PTFE substrate film, it was possible to easily fabricate a composite membrane possessing sufficient physical strength and low mass transfer resistance. Therefore, it was expected that the manufacturing method would be simple and suitable for a continuous process, thereby significantly reducing the membrane price. In addition, by using a tri-functional cross-linker, the cross-linking density was increased. The oxidation stability was greatly enhanced by introducing a fluorine moiety into the polymer backbone, and the compatibility with the perfluorinated ionomer binder was also improved. The prepared PFPEMs showed stable PEMFC performance (as maximum power density) equivalent to 72% of Nafion 212. It is noted that the conductivity of the PFPEMs corresponds to 58–63% of that of Nafion 212. Thus, it is expected that a higher fuel cell performance could be achieved when the membrane resistance is further lowered.

scholarly journals MOF Derived Catalysts for Oxygen Reduction Reaction in Proton Exchange Membrane Fuel Cell

2018 ◽  
Vol 778 ◽  
pp. 275-282
Author(s):  
Noaman Khan ◽  
Saim Saher ◽  
Xuan Shi ◽  
Muhammad Noman ◽  
Mujahid Wasim Durani ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Membrane Electrode Assembly ◽  
Reduction Reaction ◽  
Proton Exchange ◽  
Membrane Electrode ◽  
Nitrogen Doped ◽  
Nitrogen Doped Carbon ◽  
Exchange Membrane

Highly porous ZIF-67 (Zeolitic imidazole framework) has a conductive crystalline metal organic framework (MOF) structure which was served as a precursor and template for the preparation of nitrogen-doped carbon nanotubes (NCNTs) electrocatalysts. As a first step, the chloroplatinic acid, a platinum (Pt) precursor was infiltrated in ZIF-67 with a precise amount to obtain 0.12 mg.cm-2 Pt loading. Later, the infiltrated structure was calcined at 700°C in Ar:H2 (90:10 vol%) gas mixture. Multi-walled nitrogen-doped carbon nanotubes were grown on the surface of ZIF-67 crystals following thermal activation at 700°C. The resulting PtCo-NCNTs electrocatalysts were deposited on Nafion-212 solid electrolyte membrane by spray technique to study the oxygen reduction reaction (ORR) in the presence of H2/O2 gases in a temperature range of 50-70°C. The present study elucidates the performance of nitrogen-doped carbon nanotubes ORR electrocatalysts derived from ZIF-67 and the effects of membrane electrode assembly (MEA) steaming on the performance of proton exchange membrane fuel cell (PEMFC) employing PtCo-NCNTs as ORR electrocatalysts. We observed that the peak power density at 70°C was 450 mW/cm2 for steamed membrane electrode assembly (MEA) compared to 392 mW/cm2 for an identical MEA without steaming.

Evaluation of the corrosion behavior of a TiN-coated 316L SS bipolar plate using dynamic electrochemical impedance spectroscopy

2018 ◽  
Vol 42 (17) ◽  
pp. 14394-14409 ◽  
Author(s):  
S. Pugal Mani ◽  
Bhavana Rikhari ◽  
Perumal Agilan ◽  
N. Rajendran
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Fuel Cell ◽  
Impedance Spectroscopy ◽  
Corrosion Behavior ◽  
Proton Exchange Membrane ◽  
Electrochemical Impedance ◽  
Bipolar Plate ◽  
Proton Exchange ◽  
Exchange Membrane ◽  
Dynamic Electrochemical Impedance Spectroscopy

In the present investigation, the corrosion behavior of TiN-coated 316L SS was evaluated for use in a proton-exchange membrane fuel cell using dynamic electrochemical impedance spectroscopy (DEIS).

Multidimensional nanostructured membrane electrode assemblies for proton exchange membrane fuel cell applications

2019 ◽  
Vol 7 (16) ◽  
pp. 9447-9477 ◽  
Author(s):  
Guoliang Wang ◽  
Liangliang Zou ◽  
Qinghong Huang ◽  
Zhiqing Zou ◽  
Hui Yang
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Recent Progress ◽  
Proton Exchange ◽  
Membrane Electrode ◽  
Membrane Electrode Assemblies ◽  
Electrode Assemblies ◽  
Exchange Membrane

This review highlights the recent progress in multidimensional nanostructured membrane electrode assemblies for PEMFCs and DMFCs.

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