Automakers are making nearly continuous improvements to vehicle engines and structures by alloying their steels with an evolving list of special ingredients such as manganese, titanium, chromium, and nickel. But for electric cars, the essential recipe for making the physics work in electric motors and batteries can seem more than a little daunting.
One of the key ingredients in e-motors is neodymium, one of the most critical elements in the rare-earth magnets needed to create the permanent-magnet electric motors that are most common in today?s electric cars. Toyota is aiming to cut reliance on neodymium as it pushes ahead in developing a global electric vehicle.
True to their name, permanent-magnet motors?such as those in the Prius Prime and most EVs and hybrids?incorporate magnets mounted directly on or within the rotor (the rotating component of the motor), while electric current is applied to the windings of the stator (the stationary portion of the motor). Magnets that produce the power needed for EVs are rare-earth magnets, a type that’s lighter and can produce a stronger field (and thus more torque) than old-style ferrite magnets.
There are other motor designs, such as the AC induction motors that Tesla favors in its Model S and Model X or the current-excited motors being designed by some automakers for next-generation EVs (Audi is walking that path for its upcoming e-tron and e-tron Quattro). But production ease and efficiency keep automakers coming back to ...