Batteries can be a real drag. They inspire anxiety in cellphone users and drivers alike, always threatening to run out of charge before a plug can be located. In mobile devices and hybrid and battery-electric cars, lithium-ion cells are the standard, despite performance limitations that are apparent to anyone who has used them.
So far though, researchers haven’t been able to come up with a commercially-viable alternative. That’s where Toyota comes in. The Japanese carmaker believes magnesium could yield smaller, longer lasting, and more durable batteries that could be used in everything from phones to cars.
Magnesium is more stable than lithium, which means more of it could be used in a battery, allowing for greater electrical storage capacity, Toyota claims. Lithium’s greater volatility means the metal must be embedded in graphite rods when used in batteries. That reduces the actual amount of lithium, meaning there is less material to be used for storing electricity.
However, magnesium has problems of its own. Research was previously limited because there was no known electrolyte that would work with the metal. Usually a liquid, the electrolyte acts as a medium for transferring electrons between a battery’s electrodes, which is how a battery’s chemical energy is converted into electrical energy.
The solution to that problem came from a different type of energy storage technology. Toyota chemical engineer Rana Mohtadi was researching hydrogen storage materials, and realized that one of the materials she was using could work with a magnesium battery. It’s not too surprising that this crossover happened at Toyota, which has sold millions of hybrid cars, but is now aggressively pursuing hydrogen fuel cells.
Of course, as with any new research, Toyota’s progress with magnesium batteries comes with a few caveats. Success in the lab doesn’t always translate into a commercially viable product, and even when it does, the transition can take time. It could take 20 years of research before magnesium batteries reach consumers’ hands, Toyota has admitted.