The next-generation of hybrid-powered Honda vehicles, starting with the all-new Freed to be launched in Japan later this year, will be notable in being the world’s first to utilize a heavy rare earth-free hot-deformed neodymium magnet in their electric motors.
What’s the big deal? You may ask. Why is this even important? Allow us to breakdown the above mumbo-jumbo into English.
The Dangers of Rare Earth
Rare earth elements consist of seventeen different elements. Despite the nomenclature, rare earth elements are not rare in quantity. Anybody who has been following the Bukit Merah and Lynas cases in Malaysia will have at least a passing familiarity of the subject.
In their unprocessed state, rare earth minerals are toxic and radioactive, making the whole process of mining, refining, and recycling these materials both costly and hazardous. Further complicating the already difficult process of sourcing these elements is that majority of the world’s rare earth deposits are found in politically unstable locations.
Don’t worry, they are harmless when contained within your battery packs.
What do Rare Earth Elements do in Hybrid Vehicles?
One of the biggest criticism and concern on hybrid and electric-powered vehicles is that despite their obvious reduction in emissions, they do plenty of indirect damage to the environment. The reason is because the electric motors and traction batteries of these vehicles feature high quantities of rare earth materials in their construction.
Electric motors utilize neodymium magnets to generate motion. These type of magnets boast the highest levels of magnetic force. The heavy rare earth elements of dysprosium and terbium are typically added to neodymium magnets to give them increased heat resistance.
Honda's new rare earth-free magnets.
Daido Electronics Co Ltd is a mass-producer of neodymium magnets utilizing the hot deformation method as opposed to the more typically used sintering method. The hot deformation process is claimed to produce neodymium magnets with superior heat resistance properties.
In collaboration with Honda, Daido was able to further refine its hot deformation process to eliminate the need for using heavy rare earth elements in this component yet retaining a high-level of magnetic strength and heat resistance.
Whilst this latest development did not entirely eliminate the use of rare earth elements in a hybrid vehicle, it could pave the way for further reduction in use of these costly and hazardous materials in other components in the future.
Redesigned rotor for the next-generation Honda i-DCD hybrid drive motor.