I don't think that the scrappage stage of EV's has even been considered. Where do you pile up old batteries and how do you achieve an environmentally safe disposal.
When I worked with EDF they had a plan worked up with Nissan to re-purpose end of life EV batteries into grid storage arrays, packing loads of them into shipping containers to allow storage of solar-generated electricity. It wouldn't matter that the batteries were less efficient than they needed to be for an EV because they weren't going anywhere.
The idea was sound, the problem was that they couldn't get enough end of life batteries because they were lasting far longer than the predicted lifespan. It was thought that after 10 years or so the batteries would be no good for use in cars, turns out they were hopelessly pessimistic and the actual life of vehicle batteries is turning out to be far longer.
