Effect of crystal orientation of Cu current collectors on cycling stability of Li metal anodes

Li metal anodes are plagued by the low coulombic efficiency due to its interfacial instability. Many approaches were proposed to cope with this problem; however, little attention has been given to the current collector of Li anodes. In this study, we investigate the crystal orientation dependence of the cycling stability of Li anodes on single crystal Cu (111), (101), (001) and polycrystalline Cu current collectors. The cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) show that (111) and (001) achieved high current efficiency and low interfacial resistance, while (101) and polycrystalline Cu exhibit low cyclabilities. X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES) analysis revealed that the thickness of solid electrolyte interphase (SEI) varies with Cu crystal orientation, and the SEI is thinnest on the single crystal Cu (111). This tendency explained by the orientation dependence of surface energy of Cu, which corresponds to chemical activity of the s...