Enhanced Performance of Zn Electrodes Coated with Heterogeneous Nanoparticle-Based Interphase Layer Deposited via a Direct Precipitation Reaction

Abstract

Zn ion batteries have suffered from various problems, such as hydrogen gas evolution (HER), passivation of corrosion byproduct, and dendritic growth of Zn metal. Moreover, these critical issues are generally correlated with each other and the sluggish desolvation kinetics of Zn ion is one of the important causes of them. Herein, a concept of heterogeneous nanoparticle-based interphase layer (HeNIL) composed of zincophilic aluminum fluoride and hydrophilic aluminum oxide with nanodomains is firstly introduced for multifunctional protective layer of Zn metal to effectively prevent the parasitic side reactions, facilitated ion desolvation kinetics, and suppressing dendritic growth. HeNIL could enable well-balanced ion transfer process with accelerated desolvation process, ascribed to dynamic interaction between hydrated Zn ion and HeNIL. As a result, HeNIL coated Zn metal symmetric cell exhibits an enhanced lifetime over 1000 h utilizing 2.5 mAh cm^-2, and Zn/MnO₂ full cell demonstrates splendid capacity retention of 90.1% after 200 cycles using high areal high areal capacity (4.6 mAh cm^-2) positive electrode. This work primally provides unique guidance of design utilizing HeNIL for improving ion transfer kinetics and realizing long-life Zn metal batteries.

Keywords: aqueous zinc‐ion battery; desolvation kinetics; electrode–electrolyte interface; heterogeneous nanoparticle‐based interphase layer; interfacial stability; solid–electrolyte interphase.