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.
Lithium makes more sense when weight is an issue, for example when you have to carry the battery around. Sodium batteries could be good for grid storage if they can be implemented as scale cheaply enough, especially using common materials.