Enclosure/Open Cathode Fuel Cell Mathematical Model for Analyzing System Performance Under Arctic Conditions

2012 ◽  
Author(s):  
Samantha M. Miller ◽  
Marc Secanell
Keyword(s):  
Mathematical Model ◽  
Fuel Cell ◽  
Energy Transport ◽  
High Efficiency ◽  
Coupled System ◽  
Membrane Electrode Assembly ◽  
Operating Conditions ◽  
Membrane Electrode ◽  
Power Sources ◽  
Fuel Cell Stack

Polymer electrolyte fuel cells (PEFC) provide the option of a remote power source with high efficiency and minimal green-house gases, NOx, SOx and particulate matter. To protect the PEFC stack from the environment in which remote power sources are required, an actively controlled enclosure to provide optimal temperature and relative humidity to the open-air cathode PEFC stack is studied. A mathematical model of a transient, non-isothermal, lumped parameter, open-cathode fuel cell stack is developed and coupled with an enclosure model. The open-cathode fuel cell stack mathematical model includes characterization of the cathode channel, the anode channel and the membrane electrode assembly (MEA). The transient mass and energy transport equations for the coupled system are solved to determine the optimal operating conditions for the PEFC stack within the enclosure.

Fuel Cell-Based MEMS Power Source

2008 ◽  
Author(s):  
Saeed Moghaddam ◽  
Eakkachai Pengwang ◽  
Kevin Lin ◽  
Rich Masel ◽  
Mark Shannon
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Hydrogen Generation ◽  
Control Mechanism ◽  
Membrane Electrode Assembly ◽  
High Energy ◽  
High Energy Density ◽  
Membrane Electrode ◽  
Mems Devices ◽  
Power Sources

The increasing demand for high energy density power sources driven by advancements in portable electronics and MEMS devices has generated significant interest in development of micro fuel cells. One of the major challenges in development of hydrogen micro fuel cells is the fabrication and integration of auxiliary systems for generation and delivery of fuel to the membrane electrode assembly (MEA). In this paper, we report the development of a millimeter-scale (3×3×1 mm3) micro fuel cell with on-board fuel and control system. Hydrogen is generated in the device through reaction between water and a metal hydride. The device incorporates a new control mechanism for hydrogen generation that occupies only 50 nL volume (less than 0.5% of the total device volume). More importantly, the control mechanism is self-regulating and does not consume any power, enabling the micro fuel cell to operate passively, similar to a battery.

Lightweight System Design Optimization of High Reliability Compact Air Independent PEMFC Power Systems for Aerial and Space Vehicles

2016 ◽  
Author(s):  
Robert Utz ◽  
Bob Wynne ◽  
Scott Ferguson ◽  
Mike Miller ◽  
Bob Sievers ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Energy Density ◽  
Power Systems ◽  
System Design ◽  
High Reliability ◽  
Pem Fuel Cell ◽  
Operating Conditions ◽  
Membrane Electrode ◽  
Fuel Cell Stack ◽  
Continuous Power

Demand has increased for high reliability mobile power systems for space and aerial vehicles in military, scientific, and commercial applications. Batteries have traditionally supplied power in these applications, but the desire to extend mission duration and expand vehicle capabilities would require an energy density increase that is difficult for batteries to achieve. The use of pure hydrogen and oxygen reactants with high efficiency membrane electrode assemblies and novel design concepts for the fuel cell stack bipolar plates and balance of plant (BOP) components has the potential to meet the desired system energy density. This paper reviews subsystem and integrated testing of a lightweight PEM fuel cell system design for implementation into an aerial vehicle or space mission. The PEM fuel cell stack is designed for optimum efficiency at 2 kWe of power during standard operation with the capacity to provide over 5 kWe of continuous power. The passive flow control and water management subsystems provide the gas flow and humidification necessary for efficient operation and remove excess water produced by the stack under all operating regimes. Work is in progress to test the fully integrated system under expected operating conditions for potential lightweight PEMFC applications.

scholarly journals Highly conductive anion exchange membranes based on polymer networks containing imidazolium functionalised side chains

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ebrahim Abouzari-Lotf ◽  
Mohan V. Jacob ◽  
Hossein Ghassemi ◽  
Masoumeh Zakeri ◽  
Mohamed Mahmoud Nasef ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Anion Exchange ◽  
Polymer Networks ◽  
Chemical Properties ◽  
Membrane Electrode Assembly ◽  
Operating Conditions ◽  
Membrane Electrode ◽  
Anion Exchange Membranes ◽  
Polyamide 66 ◽  
Syndiotactic Polypropylene

AbstractTwo novel types of anion exchange membranes (AEMs) having imidazolium-type functionalised nanofibrous substrates were prepared using the facile and potentially scalable method. The membranes’ precursors were prepared by graft copolymerization of vinylbenzyl chloride (VBC) onto syndiotactic polypropylene (syn-PP) and polyamide-66 (PA-66) nanofibrous networks followed by crosslinking with 1,8-octanediamine, thermal treatment and subsequent functionalisation of imidazolium groups. The obtained membranes displayed an ion exchange capacity (IEC) close to 1.9 mmol g–1 and ionic (OH-) conductivity as high as 130 mS cm–1 at 80 °C. This was coupled with a reasonable alkaline stability representing more than 70% of their original conductivity under accelerated degradation test in 1 M KOH at 80 °C for 360 h. The effect of ionomer binder on the performance of the membrane electrode assembly (MEA) in AEM fuel cell was evaluated with the optimum membrane. The MEA showed a power density of as high as 440 mW cm−2 at a current density is 910 mA cm−2 with diamine crosslinked quaternized polysulfone (DAPSF) binder at 80 °C with 90% humidified H2 and O2 gases. Such performance was 2.3 folds higher than the corresponding MEA performance with quaternary ammonium polysulfone (QAPS) binder at the same operating conditions. Overall, the newly developed membrane was found to possess not only an excellent combination of physico-chemical properties and a reasonable stability but also to have a facile preparation procedure and cheap ingredients making it a promising candidate for application in AEM fuel cell.

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.

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