Atomic-Level Customization of Zinc Crystallization Kinetics at the Interface for High-Utilization Zn Anodes

ACS Nano. 2024 Feb 13;18(6):4932-4943. doi: 10.1021/acsnano.3c10394. Epub 2024 Jan 29.

Abstract

Understanding the crystallization occurring at the inner interfaces during electrochemical deposition is crucial for achieving a high reversibility in zinc anodes. However, design rules for crystallization kinetics still lack predictive power, particularly at the atomic scale, posing a significant challenge. Herein, we propose a crystal facet terminating agent, LaCl3, which modulates the preferential crystallization orientation of Zn by regulating its growth kinetics through the synergistic adsorption of dual ions. Interface molecular dynamics (MD) simulations and crucial experimental parameters reveal that the strong (002) facet texture of Zn deposits primarily depends on the adsorption of strong inhibitors. Specifically, the high adsorption free energy of Cl- on the Zn (002) facet and the concomitant aggregation of La3+ reduces the growth rate of the Zn (002) facet, thereby favoring its preservation as the final crystal facet. Consequently, this terminating agent enables the Zn anodes to deliver a high cumulative capacity of 12 Ah cm-2 at 40 mA cm-2, 20 mAh cm-2. The Zn||MnO2 full cell, when coupled with a high-mass-loading cathode and limited Zn supply, can maintain a practical areal capacity of 3.39 mAh cm-2. Furthermore, rigorous testing conditions and the successful scaling up to a 0.34 Ah pouch cell further confirm its promising prospects for practical applications.

Keywords: CFTA; Zinc-ion battery; Zn texture; crystal growth kinetics; high-areal-capacity.