It depends on the future of course, but like how lithium first showed up in phones, then laptops, then larger and larger things - if something comes out to replace lithium in certain use cases, say iron batteries for grid storage, then all that lithium can be recycled back into the mix.

Or if there's an expensive but newer medium that starts going in phones, then tablets, then laptops, then power tools, and so on - all those batteries get recycled back into the lithium pool