• Many electric vehicles (EVs) use the permanent magnetic properties of rare earth metals to make their electric motors as efficient as possible.
• Earlier this year, Tesla announced that it would abandon rare earth metals (such as neodymium) in its engines by an unspecified date, citing supply chain issues and the overall toxicity of obtaining them.
• Experts are exploring how Tesla will accomplish this feat of engineering, and whether it will require some performance trade-offs.

The future of the car is electric. Car companies and governments are moving (although not fast enough for some) from gas-guzzling living to zero-emissions highways and byways. But this future of electric vehicles is not without costs, and one of the biggest – financial and political – is the acquisition of the rare earth metals found in the magnetic motors that power the electric vehicle revolution.

Take neodymium, for example. When combined with elements such as iron and boron, it creates a continuous magnetic field. This magnetic field interacts with the electromagnetic field created by the flow of electrons through the coils of wire in the motor. This amazing piece of engineering is what spins the motor shaft and moves the Tesla EV as efficiently as possible.

earlier this year, Tesla announced its intention To create a new engine completely free of rare earth metals. Previous Tesla cars featured an AC induction motor (hence the tip of the hat to the original motor’s inventor, Nikola Tesla), which required no rare earth metals. But things changed with the Model 3 and its permanent magnet motor. Although the company has reduced the need for rare earth metals by 25 percent since 2017, the Model Y still uses 520 grams of the material, according to Tesla.

That’s all for saying rare earth metals like neodymium (and commonly used additives like dysprosium, terbium and praseodymium) are very important. But as its name suggests, it is not easy to obtain. Although they can technically be obtained from anywhere in the world, China has become a leading single store for rare earth minerals, which could pose a problem if relations between the United States and China go from bad to worse. Fearing this worst-case scenario, the Biden administration Inflation Reduction Act He calls for the production of basic components of electric vehicles locally. Therefore, while phasing out rare earth metals is certainly an engineering challenge, it has the potential to reduce financial and political costs in the long term.

But what other element could fill the magnetic gap? according to WiredThe leading candidate to replace neodymium is ferrite, an iron oxide ceramic compound found in a variety of electronics. This material comes with some serious benefits—corrosion resistance and low cost being the main ones.

But as Wired It is also noted that ferrite has about a tenth of the magnetic strength of neodymium, which means any ferrite magnet It will probably be bigger and heavier than its predecessor. And in the world of electric cars, “bigger” and “heavier” are two words you don’t usually want to hear, especially when searching for every possible mile. It helps in selling technology to the population in general.

It is unlikely that such a solution would be as simple as “making the magnet bigger”, and instead would most likely require a rework of the motor to implement this new neodymium-free design. Even if Tesla can manage a rework without major compromises, the company’s use of rare earth metals only represents a small slice of total global consumption, and these metals will likely remain vital to electronics and electric vehicles in the future.

Darren lives in Portland, has a cat, and writes/edits about science fiction and how our world works. You can find his past stuff at Gizmodo and Paste if you look hard enough.