The discovery was based on an idea from a researcher working on hydrogen storage materials for fuel cells at the Toyota Research Institute of North America, and not someone from the hybrid or electric vehicle teams.

It solves a key issue with lithium-based batteries. Because lithium is unstable and can ignite when exposed to air, the element’s ions are embedded into graphite rods for electrodes in batteries. Although this is stable, it limits the amount of energy which can be stored.

Magnesium is more stable, but Toyota says research had been limited by the lack of a magnesium-friendly electrolyte. This latest discovery highlights a non-corrosive boron-based electrolyte system which could underpin the use of magnesium in next-generation batteries. Toyota is sharing the findings to accelerate development.

“We were able to take a material that was only used in hydrogen storage and we made it practical and very competitive for magnesium battery chemistry,” said Rana Mohtadi, whose idea led the discovery.