Tracking the evolution of lithium in giants using asteroseismology: Super-Li-rich stars are almost exclusively young red-clump stars.

We report novel observational evidence on the evolutionary status of lithium-rich giant stars by combining asteroseismic and lithium abundance data. Comparing observations and models of the asteroseismic gravity-mode period spacing $\Delta\Pi_{1}$, we find that super-Li-rich giants (SLR, A(Li)~$> 3.2$~dex) are almost exclusively young red-clump (RC) stars. Depending on the exact phase of evolution, which requires more data to refine, SLR stars are either (i) less than $\sim 2$~Myr or (ii) less than $\sim40$~Myr past the main core helium flash (CHeF). Our observations set a strong upper limit for the time of the inferred Li-enrichment phase of $ 40$~Myr post-CHeF) generally have low lithium abundances (A(Li)~$ $~A(Li)~$> 1.0$~dex), shows a wide range of evolutionary states.