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Figure 4. Cycling performance of Li-metal batteries and Li-metal morphology after three initial cycles at a different C rate (E/C: electrolyte/cathode ratio and N/P: negative/positive ratio). (A) Li||LiFePO₄ cell performance at 1 C (Li thickness: 300 μm and LiFePO₄ loading: 3-4 mg cm^-2). (B) Li||NCM622 cell performance at 1 C (Li thickness: 300 μm and NCM622 loading: 4-5 mg cm^-2). (C) Li||NCM622 cell performance at 0.5 C (Li thickness: 40 μm and NCM622 loading: ≈12 mg cm^-2). Cross-section SEM images of Li-metal anodes retrieved from the 40 μm Li||NCM622 cells with (D) [Pyr_6,6][FSI, (E) [Pyr_1,12][FSI], and (F) [Pyr_3,3][FSI] containing electrolytes after 100 cycles at 0.5 C. (G) Schematic illustration of the Li-metal stabilization by lithiophobic protective layers on Li tips formed by three different IL cations [Pyr_1,12]⁺, [Pyr_6,6]⁺, and [Pyr_3,3]⁺ (from left to right). This figure is reprinted (adapted) with permission from Jang et al.^[75]. Copyright (2022) Wiley-VCH GmbH.