Toyota Halves Rare Earth Metal Content in EV Motors

Toyota Motor Corp. says it has developed magnets for electric motors that require as little as 50% as much rare earth metals.​​

The carmaker aims to introduce the technology in electric power steering systems in the first half of next decade. Applications in drive motors for electrified vehicles are expected to start within 10 years.

Toyota calls the magnets the world’s first “neodymium-reduced, heat-resistant” units. The technology eliminates the need for other costly rare-earth metals such as terbium and dysprosium.

A portion of the neodymium is replaced with lanthanum and cerium. These are also rare earth metals but cost only 5% as much as neodymium.

Toyota says it has developed a way to suppress the deterioration of coercivity (the ability to maintain magnetization) and heat resistance, a characteristic typically is achieved by using neodymium, terbium and dysprosium.

The new magnets are able to maintain the performance of current units by using a layered, high-performance neodymium grain surface and applying an optimized amount of lanthanum and cerium, Toyota says. The magnet grains also are only 10% the size of previous designs. The grains are more precisely placed, which maximizes performance and reduces the amount required. 

As sales of electrified vehicles increases, the demand for neodymium could soon outpace supply unless today’s chemistries are changed, Toyota warns. Terbium and dysprosium, found primarily on China and other potentially volatile areas, already are in short supply.

Toyota, which been developing the reduced-rare earth content technology for several year, plans to outsource production of the new magnets to suppliers. The carmaker expects electrified vehicles to account for half of its sales volume by 2030.