Effect of Li+ Addition during Initial Stage of Electrodeposition Process on Nucleation and Growth of Zn

Abstract

Zn negative electrodes are expected to be used in next-generation batteries. However, irregular shape evolution, such as mossy structures, limits its practical applications. Cationic additive species are useful in suppressing this, and Li+ is a promising species. To identify the effect of Li+ on the nucleation and growth of Zn, this study analyzed the Zn aggregation behavior during electrodeposition with Li+ at the initial stage via experimental methods and theoretical calculations using density functional theory and kinetic Monte Carlo simulations. The results suggest that Li+ affected the surface diffusion of Zn adatoms, changing the nucleation and growth during the initial stage of deposition. Li+ allows Zn adatoms to diffuse rapidly owing to the mitigation of the solvation effect on surface diffusion by forming rigid solvation of Li+ in the vicinity of the surface. This results in two-dimensional nucleation of the Zn(0001) facet, which is supported by the X-ray diffraction measurements. Li+ mitigates protrusion as the initial structure of the mossy structure. This analysis provides valuable insight into the control of the behavior of Zn adatoms and their nucleation and growth.