ICE engines only manage to turn ~15% of the stored energy in gasoline into actual work. A bit of googling suggests that jet engines are about 35% efficient. Stored electricity is much more efficiently turned into mechanical work... Electric engines have 75-90% efficiency. So, you get a lot more work or unit of stored energy.
That factor 6 already seems to include the efficiency of the engine. Pure chemical energy density of kerosene is 12000 W/kg, 24x the new battery's energy densitiy.
