Lithium ion batteries use a zeolite cathode which have atomic sized pores that safely 'stores' the metallic lithium[1]. Issue with sodium is unlike lithium sodium increases in size when reduced. That tends to damage the cathode.
For ion batteries the cathode is the big technological challenge. Has to be cheap, manufacturable, stable, conductive, and hold as high a percentage of lithium as possible.
[1] There are lithium batteries with bulk lithium cathodes. But they are hazardous.
yea but a major battery maker now has sodium ion batteries that are comparable to the lithium ones that Tesla uses in China and will be using in future cars from now on.
