Beyond lithium: sodium and solid state batteries for EVs

Read my latest update on batteries, for Yale Environment 360.

https://e360.yale.edu/features/energy-storage-sodium-solid-state  

In brief:

Lithium ion batteries have been king for portable applications (phones, laptops, drones and cars) for decades. They're still king, and still improving. In particular, the cheaper formulations (lithium iron phosphate or LFP) are more heat stable so can be packed together tighter, can be charged up to 100% more easily and some in a zip of just 10 minutes. These now account for more than half of EV batteries and will likely stay the leader for a long while.

But two new technologies are challenging lithium ion's dominance, from either end of the cost spectrum. 

Sodium batteries should in principle be cheaper and easier to source than lithium (sodium is in the salty ocean after all); they're bulkier and less energy dense, but their performance is on the rise. Watch for sodium ion battery cars coming out of China soon. And for sodium batteries in stationary applications, like storing solar energy for the grid to use after dark.

Meanwhile progress is being made on solid state batteries, which are still lithium based but swap out the liquid (flammable) electrolyte in lithium ion batteries for a solid polymer or ceramic, allowing for more energy dense electrodes like metal lithium. Watch for these in robotics applications and luxury cars around 2030, which is coming up fast.

My own car, a Kona EV, apparently uses an NMC battery of an unusual type. I had no idea when I bought it. Seems like our next car will likely be LFP or maybe even sodium -- the latter of which might be well suited to Canadian winters.

Let's wait and see!