TBH, on the car side I tend to view the current craze for the hybrid as a triumph of marketing and legislation over basic physics. At the end of the day all the power to drive the car has to come from the petrol or diesel engine. The only difference is that some of the time the power to drive from the car comes from the batteries but that pwer has to have been put into the batteries by the ICE. Just like if I pay for something with a credit card, my bank balance does not change but when the statement becomes payable my bank balance does change.
Against that the hybrid has to lug around a lot more weight, has to be more expensive to manufacture and as the batteries will have a finite life in terms of time and/or cycles will have periodic big replacemnet costs.
In the case of the pure electric cars at the moment I suppose that for someone who only does short trips they might be practical but you will still need to either own or hire a different car for any longish journey. Same problem as the hybrid as regards bettery life cycle. Not emmision free as they just move the emmisions from the tailpipe of the car to the chimney of the power station except possibly in France as they have a fair bit of nuclear.
But lets say that new battery technology, nanowire, ultra capaciter or whatever, becomes available, and it probably will. The electric car should now be practical as should the electric light aircraft, provided enough money is thrown at it.
However I can see one huge potential snag both for cars and aircraft. For it to be pracical the batteries have to have really high energy storage capacity. What happens when you do any physical damage to such a battery? That energy is going to go somewhere and not in any controlled manner.