Toward High‐Energy‐Density Initial‐Anode‐Free Lithium‐Metal Batteries via Ultra‐Thin Protective Ion‐Transport‐Promoting Interface Modification and Surface Prelithiation

Abstract Anode‐free lithium‐metal batteries (AFLMBs) are desirable candidates for achieving high‐energy‐density batteries, while severe active Li⁺ loss and uneven Li plating/stripping behavior impede their practical application. Herein, a trilaminar LS‐Cu (LiCPON + Si/C‐Cu) current collector is fabricated by radio frequency magnetron sputtering, including a Si/C hybrid lithiophilic layer and a supernatant carbon‐incorporated lithium phosphorus oxynitride (LiCPON) solid‐state electrolyte layer. Joint experimental and computational characterizations and simulations reveal that the LiCPON solid‐state electrolyte layer can decompose into an in situ stout ion‐transport‐promoting protective layer, which can not only regulate homogeneous Li plating/stripping behavior but also inhibit the pulverization and deactivation of Si/C hybrid lithiophilic layer. When combined with surface prelithiated Li_1.2Ni_0.13Co_0.13Mn_0.54O₂ (Preli‐LRM) cathode, the Preli‐LRM||LS‐Cu full cell delivers 896.1 Wh kg⁻¹ initially and retains 354.1 Wh kg⁻¹ after 50 cycles. This strategy offers an innovative design of compensating for active Li⁺ loss and inducing uniform Li plating/stripping behavior simultaneously for the development of AFLMBs.