Battery technology has still very far to go.

Lithium-based batteries will probably never make their way into airplanes as the primary source of power/propulsion. A Samsung Galaxy Note 7 is dangerous enough to make airlines ban them altogether. Imagine, what would happen if the battery packs, powering a 747 over TPAC routes, would go up in smoke (or rather explosion).

With cars that's pretty much not a problem. In the case your EV starts bursting up in flames, you can stop and get out. Try that at >33,000 ft while flying at cruising speed.