scholarly journals Simulation of the Dynamic Characteristics of a PEMFC System in Fluctuating Operating Conditions

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3596
Author(s):  
Jiangyan Yan ◽  
Chang Zhou ◽  
Zhihai Rong ◽  
Haijiang Wang ◽  
Hui Li ◽  
...  
Keyword(s):  
External Load ◽  
Proton Exchange Membrane ◽  
Membrane Electrode Assembly ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Cathode Side ◽  
Membrane Electrode ◽  
Transient Pressure ◽  
Gas Channel ◽  
Huge Impact

A greater understanding of the dynamic processes inside the stack is urgently needed to optimize the PEMFC (proton exchange membrane fuel cell). In this study, we examined the gas, water and electrochemical processes inside the stack, studied the physical dynamics of system accessories such as gas supplement, flow and pressure-regulating devices, then used Simulink to build a mathematical model of a complete PEMFC system; a segmented testing platform was built to test the spatial distribution of RH (relative humidity) and pressure, which was used to verify the simulation model; based on this model, the complicated phenomena occurring inside the stack during fluctuating operating states were calculated. Our findings showed that the pressure in the gas channel and exhaust manifolds decreased when the external load increased, changing sharply at the moment of load change. The transient pressure difference between the cathode and anode sides (several kPa) had a huge impact on the MEA (membrane electrode assembly); when the load current increased, RH in cathode and cathode channel increased gradually, and the increasing rate of anode side was bigger than that in cathode side. The influence of variance magnitude and change interval of external load were also studied based on the model.

scholarly journals Exergetic Performance of a PEM Fuel Cell with Laser-Induced Graphene as the Microporous Layer

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6232
Author(s):  
Viorel Ionescu ◽  
Adriana Elena Balan ◽  
Alexandra Maria Isabel Trefilov ◽  
Ioan Stamatin
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Pyrolytic Carbon ◽  
Membrane Electrode Assembly ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Membrane Electrode ◽  
Ohmic Loss ◽  
Microporous Layer

The microporous layer (MPL) constitutes a critical component of the gas diffusion layer within the membrane electrode assembly (MEA) of a proton exchange membrane fuel cell (PEM FC). The MPL plays a fundamental role in various processes during FC operation: control of membrane humidification, heat distribution throughout the MEA, excess water removal from the cathode, and transportation of fuel to the reaction sites. Previously, we investigated the performance of a fuel cell unit employing an MPL based on laser-induced graphene (LIG) produced by the laser pyrolysis of polymeric (polyimide) substrates. The prototype LIG-based unit was tested over the typical range of relative humidity and temperature conditions. The polarization curves observed in that study displayed broad ohmic loss regions and high stability along the concentration loss regions, an interesting electrical behavior that justified developing the present voltage-current density study for the same FC prototype compared to one bearing a commercial pyrolytic carbon black MPL. The same operating conditions as in the first study were applied, in order to properly compare the performance efficiencies between the two systems; these are evaluated by considering the thermodynamic losses influence on the exergy efficiency, to exceed any limitations inherent in the classical energy efficiency analysis.

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...

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.

Advances in Electrochemical Compression of Hydrogen

2014 ◽  
Author(s):  
Jennie M. Moton ◽  
Brian D. James ◽  
Whitney G. Colella
Keyword(s):  
Proton Exchange Membrane ◽  
Electrical Power ◽  
Systems Design ◽  
Membrane Electrode Assembly ◽  
Proton Exchange ◽  
Cost Driver ◽  
Membrane Electrode ◽  
Cost Drivers ◽  
Capital Costs ◽  
Balance Of Plant

This paper evaluates the potential for electrochemical hydrogen compression systems (EHCs) regarding their engineering performance, manufacturability, and capital costs. EHCs could enhance or replace mechanical hydrogen compressors. The physical embodiment of EHCs is similar to that of low temperature (LT) proton exchange membrane (PEM) fuel cell systems (FCSs). They also share common operating principles with LT PEM FCS and with PEM electrolysis systems. Design for Manufacturing and Assembly (DFMA™) analysis is applied to EHCs to identify manufactured designs, manufacturing methods, projected capital costs under mass-production, and cost drivers for both the EHC stack and the balance of plant (BOP). DFMA™ analysis reveals that EHC stack costs are expected to be roughly equal to EHC BOP costs, under a variety of scenarios. (Total EHC system costs are the sum of stack and BOP costs.) Within the BOP, the primary cost driver is the electrical power supply. Within the stack, the primary cost drivers include the membrane electrode assembly (MEA), the stamped bipolar plates, and the expanded titanium (Ti) cell supports, particularly at lower hydrogen outlet pressures. As outlet pressure rises, capital costs escalate nonlinearly for several reasons. Higher pressure EHCs experience higher mechanical loads, which necessitate using a greater number of smaller diameter cells and a greater tie rod mass. Higher pressure EHCs also exhibit a higher degree of back-diffusion, which necessitates using more cells per system.

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
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