Here is a pretty good overview of measures that the industry is taking to make sure that electric vehicle batteries will be recycled completely and efficiently. Battery recycling dramatically lowers the lifecycle pollutant footprint of electric vehicles because a large part of the overall footprint comes from extracting rare earth metals and manufacturing new batteries.  If we can recover those metals through recycling cost-effectively, then that part of the process can be negated in future generations of vehicles.  Since the developed world has a good track record with traditional lead-acid vehicle batteries, 99% recovery, I don’t see why it would be different for more advanced, lithium ion EV batteries.