scholarly journals Mass Spectrometry of Polymer Electrolyte Membrane Fuel Cells

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Viktor Johánek ◽  
Anna Ostroverkh ◽  
Roman Fiala ◽  
Andrii Rednyk ◽  
Vladimír Matolín

The chemical analysis of processes inside fuel cells under operating conditions in either direct or inverted (electrolysis) mode and their correlation with potentiostatic measurements is a crucial part of understanding fuel cell electrochemistry. We present a relatively simple yet powerful experimental setup for online monitoring of the fuel cell exhaust (of either cathode or anode side) downstream by mass spectrometry. The influence of a variety of parameters (composition of the catalyst, fuel type or its concentration, cell temperature, level of humidification, mass flow rate, power load, cell potential, etc.) on the fuel cell operation can be easily investigated separately or in a combined fashion. We demonstrate the application of this technique on a few examples of low-temperature (70°C herein) polymer electrolyte membrane fuel cells (both alcohol- and hydrogen-fed) subjected to a wide range of conditions.

Author(s):  
A. Jamekhorshid ◽  
G. Karimi ◽  
X. Li

Non-uniform current distribution in polymer electrolyte membrane fuel cells results in local over-heating, accelerated ageing, and lower power output than expected. This issue is very critical when fuel cell experiences water flooding. In this work, the performance of a PEM fuel cell is investigated under cathode flooding conditions. A partially flooded GDL model is proposed to study local current density distributions along flow fields over a wide range of cell operating conditions. The model results show as cathode inlet humidity and/or cell pressure increase the average current density for the unflooded portions of the cell increases but the system becomes more sensitive to flooding. Operating the cell at higher temperatures would lead to higher average current densities and the chance of system being flooded is reduced. In addition, higher cathode stoichiometries prevent system flooding but the average current density remains almost constant.


Author(s):  
Bo Ki Hong ◽  
Sae Hoon Kim ◽  
Chi Myung Kim

To date, the world has been making a massive shift away from fossil fuels towards cleaner energy sources. For the past decade, polymer electrolyte membrane fuel cells (PEMFCs) powered by hydrogen have attracted much attention as a promising candidate for eco-friendly vehicles, i.e. fuel cell electric vehicles (FCEVs), owing to their high power density, high efficiency and zero emission features. Since the world’s first mass production of Tucson ix35 FCEV by Hyundai in 2013, global automotive original equipment manufacturers (OEMs) have focused on commercialising FCEVs. In 2018, Hyundai also unveiled the second generation of the mass-produced FCEV (i.e. Nexo) with improved performances and durability compared with its predecessor. Since then, the global market for PEMFCs for a variety of FCEV applications has been growing very rapidly in terms of both passenger vehicles and medium- and heavy-duty vehicles such as buses and trucks, which require much higher durability than passenger vehicles, i.e. 5000 h for passenger vehicles vs. 25,000 h for heavy-duty vehicles. In addition, PEMFCs are also in demand for other applications including fuel cell electric trains, trams, forklifts, power generators and vessels. We herein present recent advances in how hydrogen and PEMFCs will power the future in a wide range of applications and address key challenges to be resolved in the future.


2014 ◽  
Vol 4 (5) ◽  
pp. 1400-1406 ◽  
Author(s):  
Yuta Nabae ◽  
Mayu Sonoda ◽  
Chiharu Yamauchi ◽  
Yo Hosaka ◽  
Ayano Isoda ◽  
...  

A Pt-free cathode catalyst for polymer electrolyte membrane fuel cells has been developed by multi-step pyrolysis of Fe phthalocyanine and phenolic resin and shows a quite promising fuel cell performance.


Author(s):  
Erman Çelik ◽  
İrfan Karagöz

Polymer electrolyte membrane fuel cells are carbon-free electrochemical energy conversion devices that are appropriate for use as a power source on vehicles and mobile devices emerging with their high energy density, lightweight structure, quick startup and lower operating temperature capabilities. However, they need more developments in the aspects of reactant distribution, less pressure drops, precisely balanced water content and heat management to achieve more reliable and higher overall cell performance. Flow field development is one of the most important fields of study to increase cell performance since it has decisive effects on performance parameters, including bipolar plate, and thus fuel cell weight. In this study, recent developments on conventional flow field designs to eliminate their weaknesses and innovative design approaches and flow field architectures are obtained from patent databases, and both numerical and experimental scientific studies. Fundamental designs that create differences are introduced, and their effects on the performance are discussed with regard to origin, objective, innovation strategy of design besides their strength and probable open development ways. As a result, significant enhancements and design strategies on flow field designs in polymer electrolyte membrane fuel cells are summarized systematically to guide prospective flow field development studies.


Author(s):  
Vinaykumar Konduru ◽  
Ezequiel Medici ◽  
Jeffrey S. Allen

Understanding the water transport in the Porous Transport Layer (PTL) is important to improve the operational performance of polymer electrolyte membrane fuel cells (PEMFC). High water content in the PTL and flow channel decreases the transport of the gas reactants to the polymer electrolyte membrane. Dry operating conditions result in increased ohmic resistance of the polymer electrolyte membrane. Both cases result in decreased fuel cell performance. Multi-phase flow in the PTL of the fuel cell is simulated as a network of pores surrounded by the solid material. The pore-phase and the solid-phase of the PTL are generated by varying the parameters of the Weibull distribution function. In the network model, the mass transfer takes place in the pore-phase and the bulk heat transfer takes place in the both the solid-phase and liquid phase of the PTL. Previous studies have looked at the thermal and mass transport in the porous media considering the pore size distribution. In the present study, the sensitivity of the thermal and mass transport to the different arrangements of the solid-phase is carried out and the effect of different solid-phase distributions on the thermal and liquid transport in PTL of PEM fuel cell are discussed.


Author(s):  
Sang Hern Seo ◽  
Chang Sik Lee

Water management is very important for polymer electrolyte membrane fuel cell because the fuel cell performance is decreased by flooding phenomena generated by liquid water in the cathode channels. In addition, the proton conductivity and water transport of membrane could become different by hydration contents of membrane. This study is observed water transport phenomena of cathode channels with a polymer electrolyte membrane fuel cell according to various operating conditions. In order to obtain the water images, the transparent fuel cell consists of polycarbonate window of the cathode end plate and gold coated stainless steel as the flow field and current collector of the cathode. To investigate the effects of operating conditions on the water transport, experiments were conducted under various operating conditions such as cell temperature, cathode flow rate and cathode backpressure. As operating time elapsed, it is observed that the water droplet formation, growth, coalescence and removal occurred in the cathode channel. It can be known that the high cathode flow rate prevents water flooding by removal of water in the cathode flow channel. Also, the quantity of water droplet was increased by the high cathode backpressure.


Author(s):  
Yeping Peng ◽  
Ghasem Bahrami ◽  
Hossein Khodadadi ◽  
Alireza Karimi ◽  
Ahmad Soleimani ◽  
...  

Purpose The purpose of this study is simulation of of polymer electrolyte membrane fuel cell. Proton-exchange membrane fuel cells are promising power sources for use in power plants and vehicles. These fuel cells provide a high level of energy efficiency at low temperature without any pollution. The convection inside the cell plays a key role in the electrochemical reactions and the performance of the cell. Accordingly, the transport processes in these cells have been investigated thoroughly in previous studies that also carried out functional modeling. Design/methodology/approach A multi-phase model was used to study the limitations of the reactions and their impact on the performance of the cell. The governing equations (conservation of mass, momentum and particle transport) were solved by computational fluid dynamics (CFD) (ANSYS fluent) using appropriate source terms. The two-phase flow in the fuel cell was simulated three-dimensionally under steady-state conditions. The flow of water inside the cell was also simulated at high-current density. Findings The simulation results suggested that the porosity of the gas diffusion layer (GDL) is one of the most important design parameters with a significant impact on the current density limitation and, consequently, on the cell performance. Originality/value This study was mainly focused on the two-phase analysis of the steady flow in the fuel cell and on investigating the impacts of a two-phase flow on the performance of the cell and also on the flow in the GDL, the membrane and the catalyst layer using the CFD.


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