Waste products from the steel industry can make electric cars more sustainable

Boel Ekergård is one of several researchers at University West who are investigating how ferrite from Swedish mines can replace rare earth metals in electric car engines.

As the market for electric cars is seeing explosive growth, discussions about their climate impact have spurred the need for research and development. In 2019, University West started a new research team focusing on magnetic metals in electric motors for the transport sector. Boel Ekergård is one of the team’s four researchers and two doctoral students will soon be hired.

Why are alternative materials needed for electric car motors?

“Since today’s electric car motors often contain rare earth metals that may have been extracted in mines under dubious conditions, car manufacturers are looking for other materials. They need to be able to show that the materials in the cars are sustainable from several considerations,” says Ekergård. “The supply of the rare earth metals is very limited, which means they are expensive.”

How can waste products from the steel industry be used in electric motors?

“The steel industry produces large amounts of ferrite residues, which currently are not used to a great extent. But after processing, ferrite is a magnetic metal that can be used in electric motors in the same way as rare earth metals. Since ferrite has a lower power density than the earth metals, more material is needed to produce the same motor power. An electric motor built of ferrite is about twice as big, which of course also makes it heavier. But the fact is that the electric motor accounts for only a small part of the car’s total weight.”

Why is ferrite still an option if the electric engine becomes heavier?

“In addition to having large volumes of ferrite in Sweden, it is a cheaper and more sustainable alternative. We are now investigating how to develop highly efficient electric motors with ferrite and how they can be designed to provide optimal efficiency at the lowest possible weight. We will build and test full-scale electric motors in a lab environment and probably also in a car.”

Will car drivers notice any difference if the electric engine is made of ferrite?

“It depends on the type of driving experience you want. Several of today’s electric car models have extremely fast motors that can, for example, accelerate from 0–100 km per hour in three seconds. In that case, having a light motor with materials that have a higher power density than ferrite is an advantage."

"But the majority of drivers do not need such powerful motors, and for them ferrite works fine as a material. Even if the motor becomes bigger and weighs more, it produces more power than normal driving requires. This is, of course, a trade-off for car manufacturers: What is most important – motor weight or material sustainability?”

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The research project is being conducted by University West in close collaboration with Volvo Cars, NEVS and Uppsala University.

Contact: Boel Ekergård, Associate Professor, University West. E-mail: boel.ekergard@hv.se. Tel. +46 (0)520-22 32 75.