A rare earth magnets alternative emerges
Manganese-bismuth may help meet demand of EV sector Metal Tech News - August 18, 2021
Last updated 8/24/2021 at 3:38pm
Researchers at the University of Pittsburgh Swanson School of Engineering are working with Powdermet Inc., an Ohio-based nanomaterials and advanced materials research and development company, to develop manganese-bismuth-based materials as an alternative to rare earths in permanent magnets.
The motors in most electric vehicles made today contain rare earth permanent magnets, which leverage the naturally occurring strong magnetic force offered by rare earths such as neodymium or dysprosium to power EVs down the highway.
EV motors can be made without these permanent magnets by creating magnetism with electric current. These motors, however, draw much more power from the battery pack, which means larger batteries and less range.
"Permanent magnets are used in electric motors because they can produce and maintain a strong magnetic field, even in the presence of an opposing magnetic field, as opposed to electromagnets, which require an electric current," explained Paul Ohodnicki, associate professor of mechanical engineering and materials science at the University of Pittsburg.
Though rare earths are not as uncommon as their name implies, economically viable deposits of this group of 17 elements are somewhat scarce, and the traditional process for separating the notoriously tightly interlocked rare earths into individual elements is complex.
While the United States and Canada each have one rare earths mine, there are currently no North American facilities that can separate concentrates produced at these facilities into the individual rare earths used for permanent magnets and a wide variety of other high-tech applications.
"The green technologies of the future - electric vehicles, wind turbines, wave energy, drones, and more - rely on rare earth permanent magnets not currently available from domestic suppliers, resulting in significant supply chain risk," said Andrew Sherman, founder and chief technology officer of Powdermet.
With many global governments and automakers looking to phase out internal combustion engine cars and trucks in favor of EVs by 2035, there is growing concern about whether there will be enough rare earths available to meet the needs of electric mobility and other uses for powerful permanent magnets.
This has researchers from both the public and private sectors scrambling to develop alternatives.
To foster replacements, the U.S. Department of Energy has provided $200,000 to a Powdermet-led project that hopes to create an electric machine that uses permanent magnets made of more abundant metals instead of rare-earth metals.
This funding will allow Powdermet to commercialize manganese-bismuth-based permanent magnetic materials developed at DOE's Ames Laboratory Critical Materials Institute.
"Powdermet is tremendously excited to bring our 25 years of nanostructured powder processing experience to rapidly scale production of rare earth-free magnet technology developed at CMI," said Sherman.
Powdermet is collaborating with a University of Pittsburgh research team led by Ohodnicki, which believes the magnets could help facilitate the rapid transition to electric mobility.
"Using alternative materials such as MnBi-based permanent magnets, developed at the Ames Laboratory, to create a permanent magnet instead of rare-earth metals like neodymium and dysprosium would make electric vehicles more affordable, accessible, and sustainable, and would help the U.S. become a leader in the EV market," he said.
The Pitt team will use world-leading motor design software to benchmark an electric motor design that takes advantage of these novel magnetic materials.
University of Pittsburg and Powdermet are both members of Advanced Magnetics for Power & Energy Development, a research consortium led by Ohodnicki and co-director Brandon Grainger that brings together expertise from several universities, national labs, and industry partners.
"This partnership with Powdermet is a great example of the kind of foundational research and development work we can do when we collaborate with our partners from various engineering disciplines, and we're excited by the potential impact on the future of EVs," said Grainger, who is part of the Pitt team working on the manganese-bismuth magnet project.