There's an assumption that batteries go to the rubbish dump at the end of a car's life. But they don't, they typically get employed as stationary storage. For instance, there's a Nissan parts factory in Victoria which relies on a collection of old Leaf batteries for stationary storage.
The batteries we already have can last ridiculously long. A Swasticar battery lasted over 600,000 km - ~40 years of average driving - before needing to be replaced.