This annual symposium, now in its eighth year,
featured a main conference on the latest developments
of small fuel cells for portable applications.
The symposium was hosted by the Knowledge Foundation
Technology Commercialization Alliance, and held
at L’Enfant Plaza Hotel in Washington, D.C.
The symposium was preceded by a special one-day
workshop on “Biofuel Cells and Alternative
Fuel Approaches for Mobile Power Devices.”
The following lectures were presented in the workshop:
“Microbial Biofuel Cells – Recent Technologies,
Prospects and Major Research Issues,” Uwe
Schröder, Institut für Chemie und
Biochemie, University of Greifswald, Germany;
“The Upflow Microbial Fuel Cell for Wastewater
Treatment and Electricity Generation,” Largus
T. Angenent, Washington University; “Development
of Miniaturized Enzymatic and Microbial Fuel Cell
System,” S. (Krish) Krishnamoorthy,
CFD Research Corp.; “Developing High Power
Density and Long Lasting Enzymatic Biofuel Cells,”
Shelley D. Minteer, St. Louis University;
“Promise and Challenge of Enzymatic Fuel
Cells for Medical and Portable Power Applications,”
Christopher A. Apblett, Sandia National
Laboratories; “Biofuel Cell Potential for
Portable Power,” Nick Akers, Akermin
Inc.; and “Hydrogen Generation via Aqueous-Phase
Reforming of Glycerol,” Randy D. Cortright,
Virent Energy Systems Inc.
The pre-conference workshop closed with a presentation
and demonstration by Toby Woolrych and
Damian Thomas of ACTA S.p.A. titled “Making
Renewable Fuel Cells a Reality.”
Symposium on Small Fuel Cells
for Portable Applications
The two-day symposium on small fuel cells for
portable applications was well attended with participants
from all corners of the world. The professional
makeup of the attendees included a spectrum of
scientists, engineers, managers, investors, and
potential users. The conference organization included
24 oral presentations, a panel discussion of the
portable fuel cell industry, a poster session,
and company exhibitions.
Conference attendees were welcomed by Dr. Serge
Pan, director of program development for the
Knowledge Foundation, who invited attendees to
send him suggestions for next year’s conference
and to consider participation in Fuel Cell Durability
and Performance 2006.
Plenary Session
Valri Lightner of the U.S. Department
of Energy (DOE) discussed “The Department
of Energy Polymer Electrolyte Membrane Fuel Cell
Research and Development Activities.” While
DOE has the fuel cell vehicle and hydrogen economy
as their ultimate goal, helping industry introduce
portable fuel cells represents a near-term goal.
She stated that portable targets are already within
range and represent an important step for advancing
fuel cell technology into producing it to the
public. Lightner reviewed the DOE program’s
demanding technical targets for specific power,
power density, energy density, cost and lifetime.
Critical path technical barriers to the hydrogen
economy include >300 mile range hydrogen storage
for $2-3 per gge hydrogen production cost, and
<$50 per kW transportation fuel cell costs.
George Kerchner of Wiley Rein & Fielding
LLP, spoke on “Recent Regulatory Developments
Affecting the Transport of Small Fuel Cells.”
He described advances in regulatory permission
for fuel cell cartridge transport. In January
2007 the UN and ICAO passed new fuel cell entries.
These will allow fuel cells to be introduced to
consumers without hindrances to their use and
transported by consumers worldwide. However, Kerchner
cautioned that some obstacles remain and some
fuels such as NaBH4
were not included. Exceptions enjoyed by lithium-ion
batteries such as class 9 hazardous material classification
and permission for shipping of laptops and power
tools with batteries installed have yet to be
done for fuel cells.
Hydrogen on the Spot, Hydrides
and PEM
George H. Miley, professor at the University
of Illinois, Urbana-Champaign, spoke on “Compact
Regenerative NaBH4/H2O2
Fuel Cells.” He explained that the use of
two high-energy-density fuels, NaBH4
and H2O2,
directly in the fuel cell provides a very high
specific power. Considerable R&D was necessary,
however, to develop new catalysts that promote
the fuel reactions without gas evolution and to
create proper conditions for efficient membrane
transport. Also, initial applications were presented,
including a laptop fuel cell and a UPS unit. Both
units were designed for extended operation times
to capitalize on the high energy density of the
fuels.
Takafumi Sarata, of Seiko Instruments Inc.
reported on “Small Scale Passive Type PEFC
Using Chemical Hydrides.” He discussed the
design of a hydrogen generator using a NaBH4
hydrogen generator system coupled to a fuel cell
such that the cell pressure controls the hydrogen
produce rate. The heart of the control system
involves a unique regulator value actuated by
the pressure difference between the reaction chamber
and atmosphere pressure. The result is a small
portable generator that has the reaction and liquid
chamber unified by passive control achieved through
the differential pressure value.
Paul Osenar of Protonex Technology Corp.
spoke on “Advancements in Sodium Borohydride
Fueling Subsystems for Portable Applications.”
He described a family of fuel cells in the 10-500W
range produced by Protonex, main user at present
being the military. These units generally employ
hydrogen generation from a NaBH4
fuel cartridge, developed in collaboration with
Millennium Cell Inc. A goal is to ultimately develop
an advanced stack with NaBH4 fueling that approaches
1000W/kg. With the present field units and hydrate
cartridges for Army use, ~900WHr/kg has been achieved.
Michael Lefenfeld of SiGNa Chemistry LLC
spoke on “Alkali Metals Plus Silicon Form
Convenient Pure Hydrogen Sources.” SiGNa
is developing a hydrogen generator based on NaSi
reactions with water. Reaction products are H2
and a waste compound equivalent to toothpaste.
However, NaSi reacts violently in air and water,
so SiGNa has developed a protective coating to
give a non-flammable, air stable form. This form
still gives H2 yields
>9% (mass H2/mass
powder), meeting the DOE target for such storage
systems.
Richard M. Mohring, Millennium Cell Inc.,
discussed “Hydrogen Battery Technology for
Portable Applications.” Millennium Cell is
generally focused on portable applications <
500W. They focus on “hydrogen on demand”
generators using NaBH4
and are developing hydrogen battery/fuel cell
platforms based on this with storage along with
application partners. This technology gives impressive
capability, e.g., fuel only energy densities of
~2000 WHr/kg (LH V H2)
and a practical energy density target for military
applications of >600WHr/kg.
Anand S. Chellappa of Intelligent Energy
Inc. spoke on “LPG Fueled Compact PEM Power
System: An Assessment of Practical Issues.”
Intelligent Energy has developed an integrated
membrane reformer to produce H2
from LPG and other related hydrocarbon fuels.
Current systems are for operation in the 100W
to 2kW range. These units offer high purity H2
hydrogen storage from the LPG or other liquid
fuels and a range of sizes. He presented a brief
summary of the wide range of markets for such
systems, and pointed out numerous uses that can
be formed for distributed power units in many
rural areas throughout the world.
Christopher Hebling of the Fraunhofer Institute
for Solar Energy Systems ISE provided an overview
of “Off-Grid Fuel Cell Systems for Outdoor
Use.” They have been developing portable
fuel cells since 1998 for a variety of applications.
The large market for outdoor uses, often in conjunction
with solar cells, presents several challenges
for fuel cells. One is consistent operation in
a wide temperature range. Protection of damage
by pressing and cold start up strategies were
discussed. These include reaction start up using
heating by catalytic H2
combustion.
System Design and Integration
Dr. Prasad Enjeti, Power Electronics
& Fuel Cell Power Systems Laboratory, Department
of Electrical Engineering, Texas A&M University,
spoke on “Design Considerations for a Fuel
Cell Powered DC-DC Converter for Portable Applications.”
Enjeti explained that fuel cells can be considered
as a “soft energy source” whereby stacks
can provide high voltages, but lower output voltage
single cells are most commonly used for portable
applications under 20W. Then coupling with a variable
load on the fuel cell requires a step up DC-DC
converter. He discussed a variety of designs for
converter circuitry including incorporation of
a battery or a super capacitor in parallel with
the fuel cells. The design analysis was compared
successfully with experimental data from a 30W
fuel cell with a boost converter system.
Robert Hockaday of Energy Related Devices
spoke on “MicroFuel Cells Micro Environment.”
He discussed temperature control, heat and water
management issues for micro fuel cells. A key
approach is to employ nano engineering to achieve
organized nano coil electrolyte membrane, composite
electrolytes based on layered and barrier layered
composites. A unique artificial stoma based on
plant systems has been used successfully for humidity
and temperature control in a self-regulating membrane.
Fuel and fuel product management in micro cells
was also discussed along with a description of
recent development of a varied micro stack geometry,
including spiral and cylindrical designs with
a conformal skin.
J. David Carter of the Argonne National
Laboratory spoke on “Development of a Metal-Supported
SOFC.” Carter described SOFC-based portable
power modules under development for direct methanol
or for reforming of hydrocarbons including logistic
fuel diesel and gasoline. The heart of the system
is the TuffCell SOFC design, which uses a multilayer
tape casting, slurry coating foam gas flow fields
and in situ sintering. Repeated units are co-sintered
as building blocks to improve mechanical and electrical
properties. Early testing has been quite successful
and work is continuing to improve performance
to >300mW/cm2
by modifying air and fuel electrodes. The goal
is to transfer this technology for scale-up and
system integration.
Several brief oral presentations were then given
to introduce posters. Dr. Mahmut Mat, Nigde
University, Turkey, presented “Hydrogen Storage
in Metal Hydrides.” Dr. David DeVries,
Genesis Fueltech, described his poster on “MEOH
Reformers” and Dr. Tibor Fabian, Stanford
University, introduced work on “A Planar
Air-Breathing H2
PEM Fuel Cell.”
DMFC and DEFC Systems and Components
Hyuk Chang of Samsung Advanced Institute
of Technology presented a paper on “DMFC
for Note PC and Mobile Phone: From Materials to
System.” He discussed Samsung’s development
of DMFC for notebook PCs and mobile phones. Existing
models have demonstrated a good performance. Fuel
cell cartridges have been designed for both attached
and inserted operations. He described Samsung’s
organizational structure for this development
which includes its advanced technology institute,
the industry materials division and the electoral
components division, all of which are supported
by products engineering and mobile energy business
department. Remaining issues for wide use of fuel
cells includes safety, performance under extreme
conditions and interchangeability.
Chao-Yang Wang of the Pennsylvania State
University discussed “A Paradigm Shift in
DMFC Design for Portable Power.” He provided
an overview of the fuel cell research program
at Penn State’s Electrochemical Engine Center.
Present focus is design optimization, innovative
integrations of new materials, MEA improvement,
DMFC durability, and MEA degradation at subzero
storage conditions. In the talk he stressed studies
in membrane development to reduce MeOH crossover
through the membrane. He pointed out that thermal
management strongly affects H2
and MeOH transport as well as MeOH Oxidation Reaction
(MOR) kinetics.
Yasuhiro Goto of Toshiba Corp. spoke on
“DMFC for Mobile Applications at Toshiba.”
He described the Toshiba line of DMFC prototypes
and discussed optimization of the MEA and cells.
Improvements include a carbon nanofiber support
which required low air rates plus nitridation
of catalyst alloys to increase the catalyst activity.
He stressed the advances of being able to instantly
charge a small fuel cartridge without using the
electrical outlet.
Art Homa of NEAH Power Systems presented
a paper on “Latest Developments and Performance
of Silicon-Based DMFCs.” He described the
NEAH development of Methanol-Nitric Electrochemistry
Four Generation High Power densities. This technology
is combined with an industrial concept for producing
multiple fuel cells from one silicon wafer to
reduce manufacturing cost and achieve a compact
design. The evolution of the stack design was
described, giving increasingly higher power units.
Stacks up to 16 cells are now part of NEAH’s
line. These stacks use a compact design incorporating
most of the subsystem components directly in the
unit bulkhead. By reducing individual arrangements
to a minimum, the bulkhead can be designed as
a monolithic unit, providing an interface between
the stack and the cartridge.
Claudio Bianchini of ACTA S.p.A. presented
“First Effective Direct Ethanol Fuel Cell
with Non-Noble Metal Catalysts at both Anode and
Cathode.” He described HYPERMEC™, high
performance metal catalysts, marketed by ACTA
S.p.A. These catalysts are made of Fe, Co and
Ni alone, or in binary and ternary combinations.
Other metals may be added for improvising specific
properties. Efficient operation of a unique direct
ethanol fuel cell was described as an example
of the benefits of these catalysts. When combined
with a HYPERMEC™ MEA, an air breathing ethanol
cell operating at 22°C had an electrical efficiency
of 40 to 45% and provided power densities as high
as 65mW/cm2.
Mohamed Abdou of DuPont Fuel Cells spoke
on “DuPont Direct Methanol (DMFC) Membrane
Electrode Assemblies (MEAs).” He described
DuPont Fuel Cell’s interest in turning the
MEA to fit specific portable/mobile fuel cell
applications. The goal for improved Nafion-based
membranes is to drive the cost down while increasing
cell WHr/e. The GenIV Nafion membrane reduces
flooding vs. the earlier GenII composition. Two
potential failure modes are being studied to increase
lifetime cathode flooding and Ru dissolution.
Jim Balcom of PolyFuel Inc. presented “A
Unique Perspective on Portable Fuel Cell Membrane
Design.” He discussed Polyfuel’s R&D
on a “cascade” of requirements that
must be resolved to achieve effective small size
fuel cells. Work on a hydrocarbon membrane has
focused on reducing the thickness while preventing
excessive crossover. The membrane hydrophobic
properties allow passive return of water to fuel
size.
Arnon Blum of Green Fuel Cells, Israel,
discussed “High Energy Direct Oxidation Fuel
Cell Fed by Methanol or Ethylene Glycol for Portable
Applications.” Green.Fuel.Cells is a Ramot/Tel
Aviv University spin-off formed to commercialize
the TAU extensive innovation in the field of fuel
cells. They are working on the fuel cell based
on a new low-cost membrane with high hydraulic
water permeation to simplify water management.
This is combined with a proprietary cathode, which
provides a unique water barrier layer that minimizes
the transport of liquid water outside the cathode.
First application of these cells would be for
0.5-10kW fuel generators, light motor scooters.
Small units are also under development for other
portable applications.
The Portable Fuel Cell Industry:Preparing
for Global Product Introduction
A panel discussion was held on: “The Portable
Fuel Cell Industry: Preparing for Global Product
Introduction”, James D. Balcom served
as moderator and Mohamed Abdou, Shimshon
Gottesfeld, Hyuk Chang, Yasuhiro
Goto, and Valri Lightner were the panelists.
The panel discussed various challenges that must
be faced on the route to wide dissemination of
portable fuel cells. These range from technical
issues to cost and regulations plus the need for
public education to gain acceptance of this radical
new technology. The main market to date has been
the military, although other commercial applications
are emerging. However, the general conclusion
was optimistic since progress has been rapid and
no fundamental blocks are evident.
DMFC and DEFC Systems and Components
Perry Scartozzi of MTI Micro Fuel Cell
spoke on “Development of Micro Fuel Cell
Codes and a Case Study of a Fully Integrated Micro
Fuel Cell Certified to U.S. and Canadian Standards.”
MTI Micro Fuel Cells is specializing in micro-power
(0-5W) and “high” power (5-25W) cells.
An integrated system using a fuel cell power radio-frequency
identification (RFID) reader was described. Considerable
effort was required to qualify the system and
fuel cartridges from Haviland Enterprises relative
to a maze of regulations involving national and
international commission agencies. Testing, e.g.,
cyclic exposure, altitude exposure, electro static
discharge, drop testing, abnormal operation, emission
leakage, and UN/DOT hazardous material shipping
units by FedEx involves a hazardous material surcharge.
Also FedEx was paid to provide the required transferring
for packaging and handling as described.
Larry Markoski of INI Power Systems presented
“Laminar Flow Fuel Cells (LFFC®) –
A New Approach to Overcoming the Technical Hurdles
of DMFCs.” INI is an early stage start-up
company. Their fuel cells, in the 5-100W range
for portable application are distinguished by
eliminating the standard membrane by dual flow
of the fuels using laminar flow of liquids and
a micro porous separator to prevent mixing. Designs
include MEOH with either KMnO4
or air (O2). Commercialization
challenges under study include improved cathode
performance, improved fuel utilization, stack
designs, reduction in size and weight, quantification
of cross-over and short currents and identification
of failure modes. Due to potential advances for
the INI cells, acid electrolytes (e.g. Triflic,
Phosphoric and Sulfuric acid) are under study.
Yu-Min Tsou of E-TEK, a division of PEMEAS
Fuel Cell Technologies, spoke about “Catalysts
and GDE/MEA Advancement for Performance and Cost-Effectiveness.”
E-TEK is a vertically integrated company relative
to fuel cell components, including catalysts,
diffusion layers and full MEAs. Various E-TEK
catalysts were described including high-purity
H/C, Pt/Ru, and various Pt alloys. Advantages
of Pt black-based catalysis was noted; issues
related to and measurements of catalysis dispersion
were discussed.
Douglas R. Sparks of Integrated Sensing
Systems presented “Methanol Concentration
Sensors for DMFCs.” A typical DMFC system
requires sensing and control of MEOH concentration
for optimal performance, especially relative to
the mixing of MEOH and recovered water. After
reviewing various alternatives, ISSYS selected
a density measurement for their sensor. A MEMS
design using a resonant silicon micro tube technology
is used to obtain small size and fast (seconds)
response time. Micromachining methods for manufacturing
sensors were described. Sensor performance is
good over a variety of temperature and impurity
ranges.
Conclusion
In conclusion, this year’s symposium upheld
the series tradition of providing broad insight
into a wide range of technical, business and regulatory
issues. In addition, the pre-conference provided
an area of participants with new insight into
the emerging biofuel cells. Those interested in
more information or a symposium proceeding should
contact the Knowledge Foundation at (617) 232-7400
or knowledgefoundation.com.
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