> a back of the envelope estimate for the energy density would be something like 600-700 Wh/kg.

https://www.google.com/search?q=current+tesla+battery+energy... says Tesla batteries are currently in the range of 270-290Wh/kg

Is that accurate to you?

As in this is roughly at least twice as good as current technology? Seems too good to be true. When can we expect to see it hit consumer cars? 5 years? 10 years?