By : Knowledge Foundation
Date : 2011
Location : United States US / Boston
In its 13th year, the main focus was "Fuel Cells & Hybrid Devices for Commercial & Military Applications". It is the primary source of information for end-users, developers and manufacturers of portable fuel cell powered devices.
fuel cells, Hybrid portable, Off-Grid, Porous Silicon, Direct Methanol Fuel Cells, DMFC, Solid Oxyde Fuel Cell, SOFC, Proton Exchange Membrane, PEM, Hydrogen, Borohydride, Hybrid, membrane electrode assembly, MEA
With an impressive lineup of speakers from around the world, and industry leaders exhibiting the latest technologies, this year's conference Program topics include:
• Commercial success of small fuel cells: PEM, SOFC, alkaline, direct
borohydride & DMFC
• Advances in fuel development
• Portable fuel cells for military & commercial applications
• Micro fuel cells for mobile electronics
• Hybrid portable power systems
• System integration & balance of plant engineering
• Materials challenges and use of materials-by-design approach
• Role of nanotechnology & nanomaterials
• End-user and OEM perspective on manufacturing & applications
• Safety, durability & reliability
TABLE OF CONTENTS
ADVANCES IN MATERIALS RESEARCH AND COMPONENTS DEVELOPMENT
Advanced In-Situ Characterization Techniques for the Optimization of PEM Fuel Cell Systems
Christopher Hebling, PhD, Head of Dept - Energy Technology, Fraunhofer ISE, Germany*
Due to the separation of the energy converter and the energy storage in PEM fuel cell systems, inhomogeneous in-plane conditions occur since fuel cells always need inlet and outlet ports for educts and products, respectively. The arising gradients in humidity, reactant concentrations, pressure, saturation and temperature can lead to flooding in some regions which can cause high performance losses and accelerated local degradation. To specify the state-of-health of fuel cells and to discriminate the dominant loss mechanisms, electrochemical impedance spectroscopy is a powerful characterization tool. This work presents the analysis of inhomogeneities by conducting impedance spectroscopy on a segmented 7x7 test cell with a novel synchronized 50-channel characterization system. Results from different stacks including a 28-cell Mark 1020ACS from Ballard are discussed with respect of the impedance behaviour of each single cell measured simultaneously by a multi-EIS-high-power system. Obtained data is used to develop an improved in-system diagnostic method. In order to reduce the complexity of the diagnostic tool, two discrete frequencies were chosen instead of performing a complete spectrum. Data of these two-frequency impedance measurements are discussed and compared to cell and stack voltage measurements. An impedance based control strategy that improves stability and efficiency of fuel cell operation compared to traditional designs is proposed.
*In collaboration with: R.Alink, D.Gerteisen, S.Keller, T.Kurz, C.Sadeler
Durability Approach for Air Cooled Stack Integration in a Materials Handling Application
Shanna Knights, Research Manager, Ballard Power Systems, Canada
Ballard’s 1kW FCgen®-1020ACS Air Cooled Stack, originally designed for telecommunications back-up power, is being integrated into a longer life dynamic materials handling application for small fork lift trucks through a collaboration with Plug Power. The U.S. Department of Energy funded the research activities to understand and mitigate failure mechanisms associated with the expected duty cycle, including operation under sub-zero conditions. The dominant failure mechanisms were delineated over time, including Pt dissolution, changes in Pt particle size, cathode corrosion, and membrane degradation. Testing at the stack level provided validation of small scale research diagnostic stress tests and models, enabling durability predictions of various operating strategies and design changes. Freeze related failure mechanisms and start-up under sub-zero conditions were evaluated and mitigation activities determined. The overall approach resulted in an extension of stack durability and increased functionality via integration with system design.
Ultra-Low Platinum Loading High-Performance PEMFCs Using Buckypaper-Supported Electrodes
Wei Zhu, PhD, Director of R&D Department, Bing Energy, Inc.; and
Research Scientist, ECE Dept, FAMU-FSU College of Engineering
The microstructure of the catalyst layer in proton exchange membrane fuel cells (PEMFCs) greatly
influences catalyst (Pt) utilization and cell performance. We demonstrated a functionally graded catalyst layer based on a double-layered carbon nanotube/nanofiber film- (buckypaper) supported Pt composite catalyst to approach an idealized microstructure. The gradient distribution of Pt, electrolyte and porosity along the thickness effectively depresses the transport resistance of proton and gas. A rated power of 0.88 W/cm² at 0.65 V was achieved at 80˚C with a low Pt loading of 0.11 mg/cm² resulting in a relatively high Pt utilization of 0.18 gPt/kW. The accelerated degradation test of catalyst support showed a good durability of buckypaper support because of the high graphitization degree of carbon nanofiber.
Fuel Cell With In-Situ Electrode Activity Management
Andrei Leonida, President, Axiome Advisors
The effect of catalyst poisons in a PEM fuel cell is reversed by the application of an electrical potential of appropriate polarity. Materials that would normally lose their catalytic activity continue to provide stable performance when polarized. A unique, patented fuel cell design that allows the operation under biased conditions was developed and tested. Very stable performance has been documented.
Toward an Alkaline MEA for Fuel Cells: Electrolyte, Ionomer, and Electrocatalyst
Paul F. Mutolo, PhD, Associate Director, Cornell Fuel Cell Institute; Senior Research Associate, Energy Materials Center at Cornell, Cornell University*
Abstract not available at time of printing. Please visit www.KnowledgeFoundation.com for the latest Program updates.
*In collaboration with: G.Coates, H.D.Abruña, F.J.DiSalvo
A Modular Hybrid Fuel Cell System with Energy Storage
Prasad Enjeti, PhD, Professor, Power Electronic & Clean Power Research Laboratory; and
Fuel Cell Power Systems Laboratory, Texas A&M University
A modular fuel cell system has many advantages:
(a) is capable of supplying partial load under fault conditions;
(b) is capable of supplying sudden demands in energy. A design example is presented for a 150-W, three-section fuel cell stack and dc-dc converter topology. We will present experimental results obtained on a 150-W, proton exchange membrane (PEM) fuel cell stack.
Highly Efficient Planar Micro-SOFC
Michael Stelter, PhD, Head of Department - Processes and Components, Fraunhofer IKTS, Germany
A detailed development update is given on the mass-producible eneramic® Micro-SOFC system that is being developed at Fraunhofer IKTS. Due to a strictly simplified system and well balanced internal heat and fluid streams a very high net system efficiency of well over 21% has been achieved with off-the-shelf sensors and actuators and operating on commercial fuel. The multilayer approach for the stack and further system components will be shown to be a very cost effective way to manufacture small scale, compact SOFCs. Recent system test results and data will be presented.
Direct JP-8 Fuel Cell for Portable Power
Jeff Bentley, CEO, CellTech Power LLC
CellTech has developed the Liquid Tin Anode SOFC (LTA-SOFC) for direct conversion of fuel to power. The LTA-SOFC is not harmed by sulfur or carbon so it is an ideal power source for operation on military logistics fuel as well as other commonly available hydrocarbon fuels. This talk will review the operating principles of LTA-SOFC and discuss cell, stack and system level progress in portable power.
Fuel Cells Enabling Applications
David Nicholas, Vice President, Adaptive Materials, Inc.
AMI offers high energy density SOFC power sources for military applications in portable power and unmanned vehicles, and will soon offer commercial variants of these products for industrial and leisure markets. We will present recent successes and demonstrations of our power systems in unmanned vehicles with extended duration as well as portable power systems being field tested by the US military.
Thin Film Technology for Portable Gas Batteries
Sascha Kühn, PhD, CEO and CTO, eZelleron GmbH, Germany
Microtubular Solid Oxide Fuel Cells are operational within seconds and allow a higher power density per volume than the larger version. Hence they are a potential technology for automotive, auxiliary and small scale portable power supply devices. The electrolyte layer is the heart of eZelleron’s microtubes and because it is free of pores and still submicrogranular structured the cells show extremely high power densities of more than 1.5 W/cm≤ at 800˚C. Issues of such thin layer SOFC and the way to solve them are presented.
APPLICATION AND COMMERCIALIZATION
Commercialization of Portable Hydrogen
Andrew P. Wallace, Director of the Alternative Energy Research Center, SiGNa Chemistry
SiGNa Chemistry has developed a range of commercial sodium silicide based hydrogen systems for applications requiring 1 to 300 Watts. This work will summarize the lessons learned from manufacturing the first 1,000 cartridges for a particular application.
Fuel Cells and Power Management for Military Applications
Paul Osenar, PhD, President & CEO, Protonex Technology Corporation
Protonex continues to focus on the commercialization of fuel cell systems and power management equipment for high value portable military applications. Within the military, there is a long standing need for advancements in portable and remote power. Simply providing better energy density over traditional batteries has proven not enough to propel rapid deployment. Rather the integration of high-density storage with intelligent power management is resulting in very positive signs to sustained procurement of portable field battery chargers and associated equipment. Our SPM (Soldier Power Manager) devices, M300 battery charger (Reformed Methanol, PEM Fuel Cell) and upcoming developments will be discussed.
Hybrid Power Source Integrating Solar, PEM and Sodioboro Technologies
Paolo Fracas, CEO, GENPORT srl, spin-off of Politecnico de Milano, Italy
Advanced lightweight generators, integrating the long running time of PEMFC, the quick response of batteries, the intermittent availability of solar energy and the high energy density of solid hydrogen, will ensure to extend the power need of electronic-based equipment in many off-grid contests. The hybrid concept extended to chemical storages as well as PV generation opens the door to a great amount of improvements in term of system reliability, long term energy retention and cost effectiveness. Technical challenges concerning this complex system will be illustrated with a specific focus on different hydrogen on demand strategies based on Sodioboro and metal hydrides storages providing experimental and simulation results.
Development of NaBH4-Hydrogen Generator for Deep Water Fuel Cell Applications
Martin Blechert, Portable Power Supply Group, Dept High Density Interconnect & Wafer Level Packaging, Technische Universität Berlin, Germany*
A consortium of companies and academia is developing a small fuel cell system for under water and deep-sea applications. The fuel cell features a direct H2O2 supply at the cathode and hydrogen which is produced on demand in a NaBH4 hydrogen reactor. An open concept was implemented to avoid bulky pressure vessels. Therefore reliable performance of all components at a pressure of up to 700 bars had to be demonstrated. The paper describes the design of the hydrogen reactor including thermal management and catalyst stability. A hydrogen rate control system was developed which includes a micro pump, and a bellow system as hydrogen buffer and rate monitor. Long term tests including the reactor and the PEM fuel cell will be presented.
*In collaboration with: R.Hahn, K.Höppner, S.Wagner, W.Fröhlingsdorf, J.Mainert, T.Hahn
Fuel Cell Based Portable Generators: Design and System Integration
Delia Muñoz Alé, Industrial Engineer, Systems Engineering Dept., Hynergreen Technologies S.A., an Abengoa Company, Spain
System requirements that must meet fuel cell based portable generators are not only related to the basic performance in terms of power, weight and autonomy, but also to external restrictions and regulations to comply for most commercial and military applications. The issues in the design and system integration to achieve these goals include every component of the generator and can be grouped in three distinctive areas. Some elements as the fuel cell or the output voltage regulator act as heat sources. Strategies for maintaining a proper temperature at every location are simulated. Another important issue to consider is the electromagnetic compatibility (EMC). In most simple systems where a standard low frequency controller is used, EMC compliance is not hard to reach, but when power conversion for a regulated output or PWM control of valves and fans is used, EMC problems could arise mostly because of radiated interference. EMC can be achieved by suppressing the parasitic antennae created by long wires and by reducing the bandwidth and amplitude of signals that control valves and fans. A third matter is the enhancement of the systems power efficiency. This efficiency relates the output power and the internally consumed power to make the whole system work. This efficiency is increased by the use of optimal valve and fan control algorithms as well as the use of low-power electronic circuits. Unfortunately, the use of these techniques may lead to an increase in electromagnetic emissions and, thus, a compromise between those must be reached.
*In collaboration with: A.Pérez Vega-Leal, Universidad de Sevilla; V.Mesa Velez-Bracho, G.Adame García, Hynergreen
Highly Active Carbon-Based ORR Catalysts for PEMFC
Seong Ihl Woo, PhD, Professor, Dept of Chemical & Biomolecular Engineering; Dept of Chemistry & EEWS; Director, Center for Ultramicrochemical Process Systems, Korea Advanced Institute of Science and Technology (KAIST), Korea*
As an alternative of Pt/C catalysts for oxygen reduction reaction in PEMFC, nitrogen doped carbons having various morphologies and characteristics were prepared. N-doped-CNTs grafted on Fe/C catalyst was synthesized via pyrolysis of dicyandiamide onto Fe2O3/C. Pyrolysis of DCDA at higher temperatures increased the amount of N-doping and it had positive effects on electrochemical properties toward ORRs. Two-dimensional carbon structure, graphene, was modified by N-doping via Hummers method. Around 42% of the catalyst showed the pyridinic-N site which was the most active N-doped structure towards ORRs. For an environmental friendly synthesis method, amino acids were used to prepare N-doped carbon. It also revealed that not only N-doped carbon but N, S-dual doped carbon could also be synthesized.
*In collaboration with: C.H.Choi, S.H.Park, K.R.Lee
Model-Based Analysis of Portable DMFC System Configurations
Ulrike Krewer, PhD, Prof, Max Planck Institute for Dynamics of Complex Technical Systems, Germany
Model-based system analysis and design allows detecting limitations of DMFC system designs at early project stages. This presentation gives a fundamental insight into selected active DMFC system configurations. It elucidates their theoretical capabilities and limitations with a focus on environmental reliability and fuel efficiency. Details on the feasibility envelope for water-autonomous operation and the effect of system design on efficiency are given.
Carbon Nanotube Supported MnO2 Catalysts for Oxygen Reduction Reaction and Their Applications in Small Fuel Cells
Fong Yau (Sam) Li, PhD, Professor of Chemistry, Deputy Director, NUS Environmental Research Institute, National University of Singapore, Singapore
Manganese dioxide materials were tested as alternative cathode catalysts for oxygen reduction reaction (ORR) in air-cathode microbial fuel cells (MFCs). Prepared by solution-based methods, the MnO2 nanoparticles were comprehensively characterized and incorporated into electrodes together with carbon nanotubes (CNTs). The electro-catalytic activities in neutral electrolyte were investigated by cyclic voltammetry (CV). Beta-MnO2 appeared to have the highest catalytic activity due to its structure and better interaction with carbon nanotubes.
Company Description : Includes a PDF file of 18 presentations and the transcript of the speeches given at Fuel Cells Durabilty 4th Edition series.
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