Designing Dendrite‐Free Zinc Anodes for Advanced Aqueous Zinc Batteries

Abstract

Zn metal has been regarded as the most promising anode for aqueous batteries due to its high capacity, low cost, and environmental benignity. Zn anode still suffers, however, from low Coulombic efficiency due to the side reactions and dendrite growth in slightly acidic electrolyte. Here, the Zn plating/stripping mechanism is thoroughly investigated in 1 M ZnSO 4 electrolyte, demonstrating that the poor performance of Zn metal in mild electrolyte should be ascribed to the formation of a porous by-product (Zn 4 SO 4 (OH) 6 •xH 2 O) layer and serious dendrite growth. To suppress the side reactions and dendrite growth, a highly viscoelastic polyvinyl butyral (PVB) film, functioning as an artificial solid/electrolyte interphase (SEI), is homogeneously deposited on the Zn surface via a simple spin-coating This article is protected by copyright. All rights reserved.2 strategy. This dense artificial SEI film not only effectively blocks water from the Zn surface but also guides the uniform stripping/plating of Zn ions underneath the film due to its good adhesion, hydrophilicity, ionic conductivity, and mechanical strength. Consequently, this side-reaction-free and dendrite-free Zn electrode exhibits high cycling stability and enhanced Coulombic efficiency, which also contributes to enhancement of the full-cell performance when it is coupled with MnO 2 and LiFePO 4 cathodes.

Pencil Drawing Stable Interface for Reversible and Durable Aqueous Zinc‐Ion Batteries

“…Owing to the change of pH value in the near surface of electrode, the Zn could be severely corroded as well as wrecked by dendrite formation. [ 45 ] However, only one characteristic peak of such byproduct at 12.1° displays in the cycled Zn–G electrode. Comparatively speaking, fewer byproducts are occurred on the surface of Zn–G than that of bare Zn, which is mainly due to the uniform electric field and highly reversible procedures during repeated cycling.…”

An In‐Depth Study of Zn Metal Surface Chemistry for Advanced Aqueous Zn‐Ion Batteries

“…Zn corrosion, and hydrogen evolution, which significantly compromise the Coulombic efficiency (CE), cycling stability, and practical implementation of Zn metal batteries. [2] According to our previous study, [3] fresh Zn metal is highly unstable in mild electrolyte and generates a loose Zn 4 SO 4 (OH) 6 •xH 2 O layer that cannot block the electrolyte to stop side reactions, including the hydrogen evolution, which easily causes battery swelling. It is well known that there is a dense Zn 5 (CO 3 ) 2 (OH) 6 passivation layer on the Zn metal surface due to its oxidation by contact with oxygen and moisture in the air.…”

Synergistic Manipulation of Zn2+ Ion Flux and Desolvation Effect Enabled by Anodic Growth of a 3D ZnF2 Matrix for Long‐Lifespan and Dendrite‐Free Zn Metal Anodes

“…designed a polymeric interphase layer composed of polyamide and Zn(TfO) 2 , which can not only regulate Zn deposition, but also protect the surface of the deposited Zn from the electrolyte. [ 16 ] Besides, constructing coating layers including metal–organic frameworks (MOFs), [ 17 ] nanoporous CaCO 3 , [ 18 ] poly(vinyl butyral), [ 19 ] ZnO, [ 20 ] ZnS, [ 21 ] carbon black, [ 22 ] indium‐based compounds [ 23 ] and TiO 2 /PVDF composite [ 24 ] have also been proved to be effective in delaying Zn dendrite formation and improving electrochemical performance. However, these protective layers may be cracked during long‐term cycling especially at high current densities due to the drastic volume change during Zn deposition/stripping.…”