Accelerating the Zn2+ Transport Kinetics in the Pre-Solvated Artificial Protective Layer via Preferential Electrostatic Interactions for Stable Zinc Anode.

Abstract

The intrinsic safety and cost-effectiveness of the aqueous zinc ion batteries hold the potential for grid-scale energy storage. However, the uncontrolled dendrite growth, parasitic reactions, and electrochemical corrosion of the anode due to the random Zn²⁺ transport near the anode hinder its practical applications. Herein, a pre-solvated artificial protective layer (ps-APL) with a nitrogen-containing functional group is constructed by an in situ polymerization strategy to stabilize the Zn anode via boosted Zn²⁺ mass transport kinetics and oriented exposure of the Zn(002) facets. The preferential electrostatic interaction between the nitrogen atoms and Zn²⁺ induces accelerated migration kinetics in the partially solvated protective layer, which homogenizes the ion flux and nucleation sites. Moreover, the optimized adsorption behavior of the polymer on the Zn surfaces facilitates the Zn(002)-orientated deposition, which substantially suppresses the dendrites growth. Consequently, the ps-APL-coated Zn anode delivers a stability for 2200 h at 1 mA cm^-2, enabling an 8.8-time enhancement in comparison to the bare Zn anode. More impressively, the protected Zn anode stably cycles for over 1000 h at a high current density of 5 mA cm^-2, displaying a 10-time enhancement. Consequently, Zn||VO₂ full battery exhibits stable cycling for 2100 cycles with excellent safety at 1 A g^-1.