Sodium-Air or Lithium-Air Batteries?

Around the world, developers are working on batteries more and more efficient. A plausible path would see the entry of batteries lithium-air, according to the American company IBM, lithium-air batteries would guarantee electric cars a range of 800 kilometers.

With advantages of this kind, the interest of car manufacturers is strong: the Japanese Toyota has entered into an agreement with the German BMW for the design and development of lithium-air batteries that would allow electric cars to travel at least 500 kilometers for each charge. The first lithium-air battery developed by the Toyota-BMW partner should be equipped on asports car which will be presented next year.

In the automotive landscape, groups of developers are moving in another direction. We are talking about Sodium-Air batteries. Such batteries should have a lower energy density than Lithium-Air batteries. There is talk of a density equal to 1600Wh / kg, a much lower ratio than the theoretical one estimated for Lithium-Air batteries (3450Wh / kg). To give an idea, we recall that the density of lithium-ion batteries is about 200Wh / kg.

If the Sodium-Air battery it seems too underperforming compared to the promises of the Lithium-Air battery, just think of an iPhone or a Tesla Roadster: in perspective, if the battery of theiPhone was replaced with a model sodium-air, the battery life, at the same weight, would be 8-9 times longer. As well as if the Tesla Roadster battery (116 Wh / kg) was replaced with a model sodium-air, the Tesla car would increase its range by 13 times, reaching 5,105 kilometers, enough to cover the entire perimeter of the boot (excluding Sardinia).

Let's recap the densities:
Current lithium battery: 200Wh / kg
Theoretical maximum Lithium-Air batteries: 3450Wh / kg
Estimation for Sodium-Air batteries: 1600Wh / kg

Certainly the batteries that will equip the next generation of electric cars they will be lighter and more efficient, but why should car manufacturers invest in technology sodium-air? The sodium-air batteries compared to "competitors " lithium-air, can be refilled more easily. Furthermore, the sodium it is cheaper and more abundant than the lithium.

Despite the economic advantages of sodium-air batteries, in a short time, we will see the lithium-air batteries. This is because the batteries sodium-air they can only be recharged 8 times. Researchers are working to overcome this limit but for now the heir of the current ones lithium batteries It will be there Lithium-Air battery, more expensive but lighter and more efficient.

Video: How To Make Sodium Metal (October 2020).