What's the turnaround for the aircraft though? If they can't turn around an aircraft in 15-30 min, we'll need more aircraft or prices will skyrocket (no pun).
Any sensible proposal for electric systems for commercial aircraft is going to aim for batteries to be safely swappable in 10-15 minutes. (Though they can still make delays from unexpected diversions to airports without a stock of batteries worse)
Hmmm... I wonder. Let's say they design the aircraft around an existing battery (size/weight). If later technology allows for a lighter battery, would they they have to add the weight back in order to keep the cg correct?
And then charge overnight and be used as energy storage for the time they're not in use. As flight times are very predictable, they should be a good use case for battery storage.
Supercapacitors could solve that, but unfortunately they currently have much less density even than batteries. Apparently graphene supercaps may solve that, but not at the moment.