earth's crust, low cost, and high gravimetric and volumetric capacities of 820 mAh g −1 and 5855 mAh cm −3 , respectively. [1][2][3] However, the irreversible reactions of Zn metal anodes (ZMAs), and metal anodes in general, remain a problematic issue. [4][5][6] Specifically, it correlates to accumulative dendrite growth/dead Zn and continuous electrolyte decomposition as gaseous hydrogen evolution, resulting in battery short circuit, cell gassing, and electrolyte dry-out. [7,8] Therefore, compromises in the areal capacity and utilization ratio of ZMAs (generally less than 10%) are made to achieve a "reversible" illusion. This greatly reduces the energy density of ZMA-based batteries at the full cell level, which is unsuitable for practical applications. [9,10] Constructing a high-quality solidelectrolyte interphase (SEI) for metal anodes is unambiguously regarded as an essential and favorable strategy for improving the areal capacity and obtaining a tolerable current density. [3,[11][12][13][14] Inorganic components in the SEI, such as the ZnF 2 [3,15,16] LiF, [17][18][19] and NaF [20,21] for Zn, Li, and Na metal anodes, respectively, have been shown to stabilize the interphase and improve reversibility. Specifically, the fluorinated SEI has several intrinsic merits, such as high mechanical modulus,The introduction of inorganic crystallites into a solid-electrolyte interphase (SEI) is an effective strategy for improving the reversibility of the Zn metal anode (ZMA). However, the structure-performance relationship of the SEI is not fully understood because the existing forms of its inorganic and organic components in their pristine states are not resolved. Here, a highly effective SEI is constructed for ZMA using a bisolvent electrolyte and resolved its composition/structure by cryogenic transmission electron microscopy. This highly fluorinated SEI with amorphous inorganic ZnF x uniformly distributed in the organic matrix is largely different from the common mosaic and multilayer SEIs with crystalline inorganics. It features improved structural integrity, mechanical toughness, and Zn 2+ ion conductivity. Consequently, the ZMA exhibits excellent reversibility with an enhanced plating/stripping Coulombic efficiency of 99.8%. The ZMA-based full cell achieves a high Zn utilization ratio of 54% at a practical areal capacity of 3.2 mAh cm −2 and stable cycling over 1800 h during which the accumulated capacity reached 5600 mAh cm −2 . This research highlights the detailed structure and composition of amorphous SEIs for highly reversible metal anodes.