Honda‘s next-gen electric motors reduce need for rare-earth metals
Honda and supplier Daido Steel have co-developed new magnets that reduce the need for rare earth metals.
The hot-deformed neodymium magnets are said to be a world’s first for production hybrid vehicles. The magnets do not use any heavy rare earth elements (HREEs), without compromising the necessary heat resistance for use in electric vehicle powertrains.
Heavy rare-earth elements, such as dysprosium and terbium, are typically added to neodymium magnets to improve heat resistance.
“However, major deposits of heavy rare earth elements are unevenly around the world, and also are categorized as rare metals,” Honda said in a statement. “Thus, the use of heavy rare earth carries risks from the perspectives of stable procurement and material costs.”
The Japanese automaker does elaborate on the “resource-related risks,” but the move is undoubtedly aimed at reducing reliance on China. Just a few years ago China threatened to reduce its export quotas to protect the rare metals from “over-exploitation.” Persistent friction between China and Japan, including territory disputes, adds additional pressure to seek alternative technologies.
Daido’s hot deformation method aligns crystal grains on the nanometer scale. The crystal structure is said to be approximately 10 times smaller than can be achieved using a traditional sintering process, helping achieve satisfactory heat resistance.
Honda engineers developed a new motor to accommodate the hot-deformed magnets, tweaking the rotor shape to optimize for the magnets’ particular flux characteristics. The motor achieves all of the necessary torque, power and heat resistance specs for a production vehicle.
Honda plans to use the technology in its redesigned Freed hybrid, a mini MPV sold in Japan and a few other nearby markets. The company promises to continue rolling out the technology to new models in the future.