Oriented Zinc Metal Anode Based on Directional Recognition and Assembly.

Abstract

The practical application of aqueous zinc batteries are highly limited by unsatisfied Zn anodes for the unavoidable dendrite growth and side reactions. Crystal orientation engineering is an effective way to overcome these inherent drawbacks. However, how to achieve Zn plating with manipulated crystallographic orientation is still a great challenge. Herein, a uniform (002)-oriented Zn metal anode is reported based on a directional cation recognition and crystal assembly strategy. The activated layered double hydroxide (Act-LDH) exhibits favorable adsorption energy with Zn2+ and high lattice matching with Zn (002) plane, which can be served as directional recognition layer to anchor Zn2+ and regulate crystallographic orientation of Zn as well. As demonstration, Zn crystals with ultrahigh ratio of (002)/(100) plane of 15.7 are assembled parallelly on horizontal Act-LDH, in which high CE of 99.85% maintains over 18000 cycles. The symmetric battery with (002)-oriented Zn shows stable plating/stripping process over 1650 and 420h at 1mAcm-2 /0.5mAhcm-2 and 10mAcm-2 /5mAhcm-2 , respectively, which is 9 and 12 times higher than unoriented polycrystalline Zn. Moreover, as-assembled full battery displays high specific capacity of 120mAhg-1 at 2Ag-1 over 1800 cycles.