Decoding the Electrodeposition of Zinc Anode With Dynamic Mixed Nucleation Model for Rechargeable Batteries.

Abstract

Dendrites have posed a significant threat to the cycling life of zinc (Zn) metal batteries in organic electrolyte. The deposition behavior of Zn is largely influenced by the kinetics of electrodeposition, a better understanding of which is crucial but often neglected. In this study, we provide a more refined classification of the electrodeposition and establish a novel mixed nucleation model. By fitting the chronoamperometric curves of the anode under different bias potentials based on mixed nucleation model, the dynamic evolution of the anode nucleation mode over time can be clearly classified. Also, the mixed nucleation model fitting proved that the introduction of antimony (Sb) transformed the electrochemical kinetics of the Zn anode, increasing the nucleation site density and shifting zinc deposition from mostly 3D instantaneous nucleation to uniform progressive nucleation. Consequently, the alloyed Zn exhibits a quasi-2D deposition with predominantly exposed (002) nanocrystalline crystallographic plane. The flat and regular deposition enables excellent performance: steady cycling over 2600 h life at 5 mA cm^-2, 5 mAh cm^-2 in Zn||Zn symmetric cells; dendrite-free zinc plating/stripping at 99.94% coulombic efficiency in SS||Zn asymmetric cell. The mixed nucleation model may provide new insights for the electrodeposition behavior of metal anodes.