Midstream: Accumulation and in-use stocks

The figure illustrates that lithium's in-use stock grows faster than that of any other material in this analysis, expanding from 154 thousand tonnes in 2020 to 4.1 million tonnes in 2050. At the same time, its composition shifts dramatically. Battery-grade lithium, already the dominant stream in 2020, accounts for over 90% of total in-use stock by mid-century. In contrast, industrial-grade and specialty streams peak at approximately 290 thousand tonnes and 50 thousand tonnes, respectively, during the 2040s before declining in absolute terms. Lithium's in-use stock is therefore not only expanding but also becoming overwhelmingly concentrated in a single application.

This transformation has important implications for circularity. On one hand, this rapidly growing battery stock represents an enormous future secondary resource that, unlike lithium dispersed in glass or ceramics, is recoverable in principle. On the other hand, very little of this material is available for recovery today. Battery-grade lithium entering service now typically remains in use for an average of nine years, with specific applications potentially having longer lifetimes. As a result, lithium is accumulating a significant circularity asset on a timeline that is structurally misaligned with the emerging supply constraint identified in the supply-demand balance analysis. Material only becomes available for recovery at meaningful scale during the 2030s, by which point the model projects the supply gap to be well established.

Because so much of lithium's future secondary supply is being embedded in products entering service today, the design of those products will largely determine what can be recovered in the decades that follow. Design decisions made during the deployment phase therefore influence the recoverability of material that will become available precisely when the projected supply constraint is most acute.