The University of Connecticut’s (UConn) Center for Clean
Energy Engineering has developed a new manufacturing process for fuel cells
that could make highly efficient, fuel cell-powered vehicles a viable
commercial option in the next 10 years and possibly sooner.
Professor
Radenka Maric developed the breakthrough process, which significantly lowers
production costs while maintaining maximum efficiency. The process is not
limited to hydrogen fuel cells. It can be applied in other industrial
applications to extend the durability and efficiency of larger solid oxide fuel
cells, used to heat and provide electricity to buildings, as well as
lithium-ion batteries currently used in most battery-powered, plug-in, and
hybrid cars.
Hydrogen fuel
cells, also known as Proton Exchange Membrane (PEM) fuel cells, are an
attractive alternative fuel source for vehicles because of their high level of
efficiency, low greenhouse gas emissions, and environmentally friendly
operation. They have no moving parts, and their only emission is water and
heat.
But one of
the primary drawbacks to the widespread use of the cells is that they are
expensive to manufacture because platinum, a rare and expensive metal used as
catalyst material to create energy, is one of the cell’s main components.
At UConn’s
clean energy engineering facility, Maric has developed a prototype
manufacturing process for the fuel cells that uses 10 times less catalyst
material with little waste. The low-temperature process allows for important
industrial controls and flexibility, and can be easily scaled up for mass
production.
“We are
trying to reduce the processing steps, and that is going to reduce the cost of
manufacturing,” says Maric, the Connecticut Clean Energy Fund Professor in
Sustainable Energy in the School
of Engineering’s
Department of Chemical, Materials, and Biomolecular Engineering. “Many times,
an industry starts working on something with the technologies they inherit.
They may make the first generation of products, but they are always looking for
that next generation that is better and cheaper. That is what we are focusing
on—the next generation.”
Maric is
internationally recognized for her work with fuel cells, thin films, and
nanomaterials technology. Prior to coming to Storrs in 2010, Maric was a group leader and
program manager at the National Research Council of Canada’s Institute for Fuel
Cell Innovation. Earlier in her career, she was a senior scientist and team
leader working on material development for fuel cells and batteries at the Japan Fine Ceramics Center
in Nagoya, Japan. Maric has published more
than 150 scientific papers and holds several patents.
In response
to industry demand for lower manufacturing costs, increased durability, and
increased efficiency for fuel cells, Maric created a novel production process
known as reactive spray deposition technology, or RSDT. In the process, small
particles of catalyst material, such as platinum, are shot out of a nozzle in
the form of a gas flame, where they are instantly cooled into atom-sized solids
and sprayed onto the fuel cell membrane in a carefully calibrated fine layer.
The
flame-based dispersion of the catalyst material allows it to bond to the
membrane quickly, eliminating several binding and drying steps necessary in the
current manufacturing process. By applying such a fine layer of catalyst
material and by achieving greater control of the size and saturation rate of
the particles, the RSDT process also limits waste.
The
flexibility and control standards of the process further allow manufacturers to
manage the thickness of the material layers that are applied, which is
important in fuel cell technology. Material layers in fuel cells need to be
thin enough to provide maximum conductivity when used in low-temperature
hydrogen fuel cells, yet thick enough to prevent corrosion and maintain
durability at the high temperatures at which solid oxide fuel cells operate.
The RSDT
process can also be applied in the production of more advanced lithium-ion
batteries. Similar to what it does with hydrogen fuel cells, RSDT’s direct dry
application of the nanocoatings used inside the battery eliminates several
binding steps in the current manufacturing process. Its high level of particle
control and flexibility allows developers to use less material at less cost.
Industry
interest
Several Connecticut companies, including Sonalysts Inc. of Waterford and Proton OnSite of Wallingford,
are currently considering Maric’s production techniques for industrial and
commercial applications.
Researchers
at Sonalysts are helping the U.S. Office of Naval Research find ways to improve
the safety and reliability of lithium-ion batteries through the use of
nanotechnology and advanced thermal management. The company is also
investigating new ways to improve the efficiency of Proton Exchange Membrane
fuel cells by reducing the amount of the required catalyst.
“Professor
Maric’s rapid spray deposition technology offers the potential of performance
and reduction of manufacturing costs for both of these products,” says Armand
E. Halter, vice president of applied sciences at Sonalysts. “Our initial
tasking is directed to investigate the benefits of RSDT to enable catalyst
deposition directly upon high-temperature membranes … at substantially lower
weight loadings. … With good results, we anticipate expansion of this
development work as the program moves forward.”
At Proton
OnSite, a global hydrogen energy and technology company, Katherine Ayers, the
company’s director of research, says she, too, is interested in Maric’s use of
the reactive spray deposition technique.
“Our interest is in the potential for this technology to enable much lower
amounts of expensive catalyst metals, while still providing mild processing
conditions at the membrane surface to avoid damage to the membrane,” says
Ayers. “We also believe this technology has the ability to substantially reduce
labor and scrap, especially due to the short shelf-life of most inks currently
used for electrode processing.”