Electrodeposited ZnO/Zn(OH)2 Nanosheets as a Functional Interface for Dendrite-Free Lithium Metal Anodes

Abstract

Modifying the current collector is a promising strategy to enable Li metal anodes with minimal Li consumption. Herein, a scalable electrodeposition method is introduced to construct 3D ZnO/Zn(OH)₂ nanosheets on Cu foil (ZOH NSs–Cu foil). Cu(OH)₂ nanowires are first formed via anodization, followed by electroconversion of Cu²⁺ and Zn²⁺ ions. DFT calculations reveal that the ZOH NSs–Cu foil exhibits high Li adsorption energy, imparting strong lithiophilicity and lowering the Li nucleation overpotential. The 3D nanosheet structure provides a large electrochemically active surface, reducing the effective current density. Furthermore, ZOH NSs–Cu foil exhibits low charge transfer resistance and promotes a Li₂O/LiF-rich solid electrolyte interphase (SEI) layer, further reducing interfacial resistance. SEM analysis and simulations confirm uniform Li deposition on ZOH NSs–Cu foil. In asymmetric cells (1 mAh cm⁻² at 1 mA cm⁻²), ZOH NSs–Cu foil supports stable cycling for over 400 cycles. Furthermore, a full cell coupling a LiFePO₄ (LFP) cathode with a Li@ZOH NSs–Cu foil anode retains high capacity with ≈100% Coulombic efficiency over 350 cycles at 1 C, even at an N/P ratio of ≈1.9. This binder-free, scalable approach offers precise Li deposition control and excellent electrochemical performance, advancing the practical application of Li metal anodes.