Tailored Covalent Organic Framework Interphase Layer for High‐Performance Anode‐Free Lithium Metal Batteries

ABSTRACT Anode‐free lithium (Li) metal batteries represent a promising candidate for high‐energy‐density energy storage, yet their practical implementation is hampered by the poor reversibility and kinetics of Li plating/stripping reactions, leading to limited areal capacity and rate capability. Here, we report a tailored covalent organic framework (COF) material as an efficient interphase layer for high‐performance anode‐free Li metal batteries. The abundant nitrogen‐containing functional groups in this COF interphase layer serve as favourable adsorption sites to homogenize Li + flux, and its well‐defined porous architecture further induces dense and uniform Li growth at high areal capacity up to 20 mAh cm −2 , suppressing Li dendrite growth and parasitic reactions. The resulting COF‐Cu/LiFePO 4 anode‐free batteries with a practical areal capacity of 4.1 mAh cm −2 exhibited decent rate capability of 3 C, indicating the potential in high‐energy‐density and high‐rate batteries. Our results unveiled tailored COF materials as a promising platform for interfacial engineering of high‐performance anode‐free Li metal batteries.