Intrinsic Zinc in Brass Enables Lithium Anode Dendrite‐Free

Abstract Brass foil, composed of copper (Cu) and zinc (Zn), is a commercialized low‐cost Cu‐based matrix with lithiophilic properties. However, brass has never been employed as a current collector of lithium (Li) metal anode to suppress formation of Li dendrite. Here, we show that brass foil is directly utilized as a current collector for Li metal anodes. It exhibits a stable repeated Li plating and stripping for more than 400 h (200 cycles) with a low overpotential (∼0.018 V) and a capacity of 1 mAh cm−2 at a current density of 1 mA cm−2 in a symmetric cell, as well as a higher average Coulombic efficiency of 97.2 % for more than 120 cycles with a capacity of 1 mAh cm−2 at a current density of 0.5 mA cm−2. Thanks to the lithiophilicity of homogeneous Zn in brass, the nucleation overpotential of Li is effectively reduced and Li is uniformly deposited on the current collector without dendrite formation. Our investigation might inspire the ancient brass to apply to lithium‐ion battery.