Any claims of better than 2x should be viewed through a hugely skeptical eye.
1) 2x would take an electric car from 300 miles range to 600 miles range. That is a pretty radical improvement in energy density that possibly exceeds even hydrocarbons.
2) Automotive is a terribly unforgiving environment for batteries. Heat, cold, and vibration are all the worst. Oh, and don't do something silly like emit toxic fumes or explode when someone ruptures your containment with a 30mph crash.
1) 2x would take an electric car from 300 miles range to 600 miles range. That is a pretty radical improvement in energy density that possibly exceeds even hydrocarbons.
2) Automotive is a terribly unforgiving environment for batteries. Heat, cold, and vibration are all the worst. Oh, and don't do something silly like emit toxic fumes or explode when someone ruptures your containment with a 30mph crash.