Dendrite-Free Anodes Enabled by a Composite of a ZnAl Alloy with a Copper Mesh for High-Performing Aqueous Zinc-Ion Batteries

Abstract

Aqueous zinc-ion batteries (ZIBs) have attracted considerable attention because of their low cost, high intrinsic safety, and high volumetric capacity. However, unexpected dendrite growth and side reactions that arise at the Zn anode can severely hinder the mass adoption of ZIBs in practical applications. Herein, we report a dendrite-free ZIB anode via the hybridization of a eutectic ZnAl alloy with a copper mesh (denoted as ZnAl@Cu-mesh). The eutectic structure of the ZnAl alloy is composed of alternating Zn blocks and Al nanoflakes. The Al nanoflakes sacrificially consume the oxygen in the electrolyte to form an Al 2 O 3 /Al shell−core structure, which in turn guides the Zn deposition process by restraining the lateral diffusion of zinc ions and hence reducing the extent of dendrite formation. This process can synergistically reduce the likelihood of Zn passivation, which allows the Zn region to remain electrochemically active for the Zn stripping/plating process. Meanwhile, a copper mesh is used as a scaffold to provide uniform electric field distribution.

Towards Understanding the Corrosion Behavior of Zinc‐Metal Anode in Aqueous Systems: From Fundamentals to Strategies

“…The design of different types of zinc alloys has become a proven strategy to inhibit HER and zinc corrosion. [50,[103][104][105][106][107][108][109][110][111] Compared to pure zinc, the formation of intermetallic phases leads to higher chemical bonding strength between phases, denser arrangement of atoms and lower Gibbs free energy (Figure 13). It increases the hydrogen precipitation overpotential and causes a positive shift in corrosion potential with a decrease in corrosion current density.…”

“…The design of different types of zinc alloys has become a proven strategy to inhibit HER and zinc corrosion [50,103–111] . Compared to pure zinc, the formation of intermetallic phases leads to higher chemical bonding strength between phases, denser arrangement of atoms and lower Gibbs free energy (Figure 13).…”

Stabilizing Zinc Electrodes with a Vanillin Additive in Mild Aqueous Electrolytes

“…Considerable efforts have been dedicated to enhancing Zn anodes, such as constructing hierarchical architectures, − building artificial protective layers, , and formulating electrolytes. − Among them, aqueous electrolyte regulation is a convenient approach to stabilize Zn electrodes . For example, “water-in-salt” highly concentrated aqueous electrolytes have been proposed to reduce the water activity and side reactions. , In addition, designing aqueous–organic hybrid electrolytes by coupling with organic solvents (e.g., dimethyl carbonate, dimethyl sulfoxide, and antisolvents) can modulate the Zn 2+ solvation shell to decrease the number of solvating H 2 O molecules, thus alleviating the generation of byproducts.…”

Surface and Interface Engineering of Zn Anodes in Aqueous Rechargeable Zn‐Ion Batteries

“…Compared to pure metal supports, zincophilic and chemically stable alloy seeds with non-galvanic corrosion, tunable elemental components, and low nucleation barrier have been considered as promising Zn anode supports, and examples include zinc-silver (Zn-Ag), zinc-tellurium (Zn-Te), zinc-tin (Zn-Sn), zinc-copper (Zn-Cu), and zinc-aluminum (Zn-Al) alloys. [65][66][67][68][69][70][71] Some metals such as Ag, Te, and Sn can "in situ" alloy with metallic Zn during the initial Zn plating and then serve as a support that further provides the Zn 2+ ions deposit sites. For example, Xue et al constructed a Ag nanoparticlecovered carbon cloth to realize reversible and dendrite-free Zn anodes for ZIBs (Figure 5A).…”