“…Possible candidates for this peak include Li 2 CO 3 , LiOH, RO−Li, LiF, Li 3 N, and Li 2 S. 21,41,47,48 However, the absence of matching peaks in the O 1s, F 1s, N 1s, and S 2p spectra at 0 V rules out LiOH, LiF, Li 3 N, and Li 2 S. In agreement with this work, no LiF was observed at the interface between triglyme:LiTFSI solvate ionic liquid and Cu at 0 V, indicating minimal TFSI − degradation. 34 According to the relative atomic composition, the concentration of lithium species is approximately 5 times larger than the CO 3 2− concentration; see Figure S12. Hence, it can be concluded that the Li 1s peak does not exclusively belong to Li 2 CO 3 .…”