Fig. 2.

Cross-section SEM images of the Li layer plated on the Cu current collector after 3 and 20 cycles under 2 mA cm⁻²–10 mAh cm⁻² conditions for the Li||Cu cells (A and B) without and (C and D) with LiNO₃. (Insets) Enlarged images of the corresponding cross-sections of the Li layers. (E) N 1s XPS spectra at various depths of the plated Li layer on the Cu current collector after three cycles under 2 mA cm⁻²–10 mAh cm⁻² conditions for the Li||Cu cell with LiNO₃.