Looks like the created cell is 614 Wh/L from the above comment. Gasoline is ~2.2kWh/L [0]. So my take is that even with the created cell the density is not going to be an issue with car or grid batteries -- only <4 times the size even at this non-theoretical cell. Who knows how the packs will be configured though as I am sure airflow will be a design consideration when making larger packs.
[0] This uses the 3kWh/kg that was provided above and a density of gasoline of .75g/mL
units
You have: 0.7429 g/mL * 3 kWh/kg
You want: kWh/L
* 2.2287
[0] This uses the 3kWh/kg that was provided above and a density of gasoline of .75g/mL