Cu‐Modified Ti3C2Cl2 MXene with Zincophilic and Hydrophobic Characteristics as a Protective Coating for Highly Stable Zn Anode

Abstract Zn anode is a promising candidate for aqueous batteries, but suffers from the dendrite growth and side reaction issues, leading to short cycling life and unsatisfactory reversibility. Herein, a Cu‐modified Ti 3 C 2 Cl 2 MXene (Cu‐MXene) with high zincophilic and hydrophobic property is prepared with a one‐step molten salt etching method. Serving as a protective coating on Zn anode, the Cu‐MXene can provide massive nucleation sites and uniformize the charge distribution, leading to homogenous Zn deposition. Moreover, the hydrophobic coating can prevent the Zn anode from the aqueous electrolyte, beneficial for suppressing the side reactions such as hydrogen evolution reaction and corrosion. Therefore, the stable and reversible Zn plating/stripping is achieved for the Zn anode coated by the Cu‐MXene, which delivers an extended cycling life of over 1000 h with a low polarization within 120 mV at 10 mA cm −2 , and a high coulombic efficiency of over 99.6% for 1100 cycles, indicating excellent stability and reversibility of Zn stripping/plating. The practical full cell coupled with NaV 3 O 8 ·1.5H 2 O cathode also displays stable performance for 1000 cycles. The proposed Cu‐MXene coating reveals a promising prospect for designing highly stable Zn anode, which can also be extended to other energy storage systems based on metal anodes.