They're already working on recycling centers for that, and also developing new technologies that don't rely on lithium. I've seen some sodium ones mentioned, but the scale isn't there yet to make them reasonable for smaller applications like cars. Like any new technology, will get there eventually.
Circling back to the solar discussion, I'm surprised we haven't looked at molten salt as a viable large-scale option in places like Arizona. Since they just use mirrors, you don't have to worry about solar panel manufacturing. Also, the molten salt retains most of its heat overnight so it can generate power 24 hours a day. I'm sure there are plenty of reasons why, I just haven't read any good reasons yet.