The problem for small cars is that while the specific energy (J/kg) is better than lithium ion the energy density (J/L) is most likely lower. In small cars the

The problem for small cars is that while the specific energy (J/kg) is better than lithium ion the energy density (J/L) is most likely lower. In small cars the volume occupied by the battery is a significant constraint. But it's good to see some competition, at least it will be if it works.