By comparison, a regular regional jet probably has around 40 MWh of energy in jet fuel.
It would really suck to have to go through security after your first flight whenever you are connecting.
Even if the batteries could be made entirely inert, the ability to deliver a plane sized slug of kinetic energy to a building of your choice retains most of the danger.
Even if that could be avoided, a plane must remain operational enough throughout all flights to avoid falling out of the sky.
It would take a large bomb to take out a whole bus load of passengers, a very small one to put safety critical systems of a plane out of action.
As much as I would appreciate this happening, I don't think electric planes are going to make it happen.
Nit: a lithium ion battery fire isn't a lithium fire, it's the electrolyte. Lithium ion batteries don't use elemental lithium. Thankfully.
Gasoline on the other hand …
Plus, depending on the battery chemistry, that material could also create a serious fire; it is a lot of stored energy either way.
So, I would not wait for it