BY AMY MAST AND NICOLE CASAL MOORE
Jeff Sakamoto (left), Anna Stefanopoulou (right)
Two new Department of Energy grants that total $5.4 million will let University of Michigan engineering researchers work on “transformational” engine and battery projects. Their efforts could lead to efficiency gains in cars and trucks, the electrical grid, and beyond.
The grants are part of $125 million in funding that the Department of Energy’s Advanced Research Projects Agency – Energy, also known as ARPA-E, recently doled out to 41 groups across the nation. The projects were chosen because they “advance US energy security and help achieve climate goals,” according to an ARPA-E statement. The agency announced the grants in conjunction with the COP21 United Nations climate negotiations, which started Monday in Paris.
“The ARPA-E projects selected today highlight how American ingenuity can spur innovation and generate a wide range of technology options to address our nation’s most pressing energy issues,” said U.S. Energy Secretary Ernest Moniz. “As we look beyond COP21, the energy technologies the Department of Energy invests in today will provide the solutions needed to combat climate change and develop a global low-carbon economy in the future.”
The U-M project leaders are Jeff Sakamoto, an associate professor of mechanical engineering; and Anna Stefanopoulou, a professor of mechanical engineering. Both are affiliated with U-M’s Energy Institute.
Sakamoto receives $3.5 million to search for a battery construction method that can eclipse lithium-ion batteries, the current industry standard. While widely used, lithium-ion batteries are fragile, flammable, temperature-sensitive and not rechargeable. They are also relatively expensive to manufacture.
“I have been working on Li-ion batteries for nearly 20 years. It’s a great technology, but transitioning society away from fossil fuels will require more advanced batteries, especially for vehicle electrification,” Sakamoto said.
The batteries he envisions, which would be nonflammable, could be used in cars and trucks, as well as in the electrical grid. Better grid-scale batteries could make solar and wind power more feasible because they could provide storage when it’s cloudy or when the air is still.
Like many energy storage researchers, Sakamoto has been exploring solid-state batteries, which don’t include liquid electrolyte. Liquid electrolyte contributes to many of the lithium-ion battery’s limitations. His APRA-E proposal aims for an inexpensive, highly efficient solid-state battery that is tough and safe enough to power a vehicle.
His approach, however, comes with a twist. Many researchers feel that new electrolytes must be developed to meet the conductivity threshold required for a true battery breakthrough. With the recent discovery of a promising ceramic electrolyte, Sakamoto posits that existing materials are fine, and what’s really needed is a groundbreaking design and manufacturing process. He’ll work with researchers from U-M, Ford Motor Company, Oak Ridge National Laboratory, the Army Research Laboratory, Solid Power, and the University of Rochester.
Stefanopoulou receives $1.9 million to develop technologies for highly efficient and responsive small automobile engines.
“Modern engines are becoming smaller and smaller with high levels of dilution for efficiency,” Stefanopoulou said. “But the lack of extra muscle makes them slower to respond than their bigger counterparts. If we improve the responsiveness of small engines, then we can push for more efficient cars at low cost.”
Proposed U.S. regulations would require that vehicles double their fuel efficiency in the next decade.
To get small and diluted combustion engines to perform more like their larger cousins, Stefanopoulou has plans to help them “breathe” faster. An engine’s response depends on its ability to take in fresh air and convert it to power.
Her method will augment traditional turbocharging to provide frugal yet instant air flow control while utilizing stored energy from regenerative braking and exhaust energy in a small 48V battery shared with start-stop functionality, Stefanopoulou said. The application would be futuristic low-cost, small, ultra-clean hybrid cars.
Stefanopoulou is a professor of mechanical engineering and director of the U-M Automotive Research Center.