JAC Motors, a Volkswagen-backed Chinese automaker, unveiled the first mass-produced EV with a sodium-ion battery through its new Yiwei brand. Although sodium-ion battery tech has a lower density than lithium-ion, its lower costs, simpler and more abundant supplies and superior cold-weather performance could help accelerate mass EV adoption.
Yes, you need to make the puncture proof, they are a fire hazard if stored at home, they degrade over time and if left empty long enough might not even work, etc.
The enginnering part is for sure one of the reasons we don’t see that idea in the wild (yet?).
The fire hazard at home and degradation when stored full or empty (speaking of lithion ion based batteries here) go away if you lean on the rental approach.
Wouldn’t it be nice to save investment and weight by using the required amount of battery capacity while still being able to extend the range of your car easily when needed?