Dendrite‐Free Reverse Lithium Deposition Induced by Ion Rectification Layer toward Superior Lithium Metal Batteries

Considerable endeavors are developed to suppress lithium (Li) dendrites and improve the cycling stability of Li metal batteries in order to promote their commercial application. Herein, continuous zinc (Zn) nanoparticles‐assembled film with homogenous nanopores is proposed as a modified layer for separator via a scalable method. The in situ formed LiZn alloy film during initial Li plating can serve as a Li+ ion rectification and lithiophilic layer to regulate the nucleation and reverse deposition of Li. When applied in Li|LiFePO4 full cells with traditional carbonate‐based electrolyte, the modified separator enables outstanding cycling stability of up to 350 cycles without capacity loss at a large rate of 5 C (3.4 mA cm−2) and a remarkable reversible capacity of 144 mAh g−1 after 120 cycles at a commercial mass loading as high as 19.72 mg cm−2. The excellent electrochemical performances are ascribed to the dendrite‐free reverse Li deposition induced by modified layer by means of its lithiophilic property for regulating homogeneous Li nucleation on the separator as well as its well‐distributed nanopores for homogenizing Li+ ion flux and enhancing electrolyte wetting. A zinc nanoparticles‐assembled film with even nanopores is modified on the surface of the separator to rectify Li+ ion flux and promote the dendrite‐free reverse lithium (Li) deposition. When applied in Li|LiFePO4 full cells with traditional carbonate‐based electrolyte, the modified separator enables outstanding cycling and rate performances at a cathode mass loading over 19.72 mg cm−2.