Anode‐free lithium‐metal batteries employ in situ lithium‐plated current collectors as negative electrodes to afford optimal mass and volumetric energy densities. The main challenges to such batteries include their poor cycling stability and the safety issues of the flammable organic electrolytes. Here, a high‐voltage 4.7 V anode‐free lithium‐metal battery is reported, which uses a Cu foil coated with a layer (≈950 nm) of silicon–polyacrylonitrile (Si‐PAN, 25.5 µg cm−2) as the negative electrode, a high‐voltage cobalt‐free LiNi0.5Mn1.5O4 (LNMO) as the positive electrode and a safe, nonflammable ionic liquid electrolyte composed of 4.5 m lithium bis(fluorosulfonyl)imide (LiFSI) salt in N‐methyl‐N‐propyl pyrrolidiniumbis(fluorosulfonyl)imide (Py13FSI) with 1 wt% lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) as additive. The Si‐PAN coating is found to seed the growth of lithium during charging, and reversibly expand/shrink during lithium plating/stripping over battery cycling. The wide‐voltage‐window electrolyte containing a high concentration of FSI− and TFSI− facilitates the formation of stable solid‐electrolyte interphase, affording a 4.7 V anode‐free Cu@Si‐PAN/LiNi0.5Mn1.5O4 battery with a reversible specific capacity of ≈120 mAh g−1 and high cycling stability (80% capacity retention after 120 cycles). These results represent the first anode‐free Li battery with a high 4.7 V discharge voltage and high safety. 4.7 V Cu@Si‐PAN/LiNi0.5Mn1.5O4 anode‐free Li batteries with a reversible specific capacity of ≈120 mAh g−1 and high capacity retention of 80% after 120 cycles are reported. With the nonflammable F‐rich ionic liquid electrolyte and the seeding Si‐PAN layer (950 nm), an enhanced safety and high‐voltage anode‐free Li battery without dendritic Li growth is demonstrated.