Scientists working at Toyota Research Institute North America have cracked magnesium as a material for batteries.
This is a very big deal as it means lots of advances in battery tech. By using magnesium, which doesn't degrade like lithium-ion, the battery will last longer. On top of that there is no need to create shielding for the electrolyte, like in current lithium-ion batteries, meaning it can be made for cheaper. It'll also be less impactful on the environment.
Of course what most people want is battery life enhancement, which this should offer too as it can be far smaller with way more density. So if you had a similar sized magnesium battery to current lithium-ion, you'd get a lot more life. Magnesium has far more capacity thanks to the number of electrons it has over current offerings.
As batteries become more prevalent, powering our phones and even cars, lithium is becoming more finite and more expensive. It won't last forever or remain affordable so alternatives, that can actually work better anyway, are most welcome and sought by companies.
At the moment this is still in the laboratory developmental phases. The company says we shouldn't expect to see it in our phones and cars for sometime yet as this will need to undergo a lot more development and testing.