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.

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

Platinum Dissolution in Proton Exchange Membrane Fuel Cell Under Mechanical Vibrations

2011 ◽  
Author(s):  
Georgiy Diloyan ◽  
Parsaoran Hutapea
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Automotive Application ◽  
Cathode Side ◽  
Accelerated Test ◽  
Mechanical Vibrations ◽  
Platinum Dissolution ◽  
Exchange Membrane

One of the factors that affect the performance of proton exchange membrane fuel cells (PEMFC) is the loss of electrochemically active surface area of the Platinum (Pt) based electrocatalyst due to platinum dissolution and sintering. The intent of the current research is to understand the effect of mechanical vibrations on the Pt particles dissolution and overall PEMFC performance. This study is of great importance for the automotive application of fuel cells, since they operate under a vibrating environment. Carbon supported platinum plays an important role as an electrocatalyst in PEMFC. Pt particles, typically a few nanometers in size, are distributed on both cathode and anode sides. Pt particle dissolution and sintering is accelerated by a number of factors, one of which is potential cycling during fuel cell operation. To study the effect of mechanical vibrations on Pt dissolution and sintering, an electrocatalyst (from cathode side) was analyzed by SEM/EDS (Energy Dispersive Spectroscopy). The performance, dissolution and sintering of the Pt particles of 25 cm2 electrocatalyst coated membrane were studied during a series of tests. The experiment was conducted by running three accelerated tests. Each test duration was 300 hours, with different parameters of oscillations: one test without vibrations and remaining two tests under vibrations with frequencies of 20 Hz and 50 Hz (5g of magnitude) respectively. For each of the three tests a pristine membrane was used. The catalyst of each membrane was analyzed by ESEM/EDS in pristine state and in degraded state (after 300 hours of accelerated test). In order to specify the same area of observation on a catalyst before and after accelerated test, a relocation technique was used.

Modeling of Proton Exchange Membrane Fuel Cell (PEMFC) Performance by Using Genetic Algorithm-Polynomial Neural Network (GA-PNN) Hybrid System

2012 ◽  
Author(s):  
Mehdi Mehrabi ◽  
Sajad Rezazadeh ◽  
Mohsen Sharifpur ◽  
Josua P. Meyer
Keyword(s):  
Neural Network ◽  
Genetic Algorithm ◽  
Fuel Cell ◽  
Relative Humidity ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Cathode Side ◽  
Data Set ◽  
Polynomial Neural Network ◽  
Exchange Membrane

In the present study, a genetic algorithm-polynomial neural network (GA-PNN) was used for modeling proton exchange membrane fuel cell (PEMFC) performance, based on some numerical results which were correlated with experimental data. Thus, the current density was modeled in respect of input (design) variables, i.e., the variation of pressure at the cathode side, voltage, membrane thickness, anode transfer coefficient, relative humidity of inlet fuel and relative humidity of inlet air. The numerical data set for the modeling was divided into train and test sections. The GA-PNN model was introduced with 80% of the numerically-validated data and the remaining data was used for testing the appropriateness of the GA-PNN model by means of two statistical criteria.

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