Multifunctional Core-Shell Structured Interface Layer Regulate Zn Deposition Behavior and Anti-Polyiodide Ions...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Zinc-iodine (Zn-I₂) batteries offer high voltage and abundant resources but suffer from zinc dendrite growth and polyiodide shuttling.
• These issues limit the practical application and cycle life of Zn-I₂ batteries.

Purpose of the Study:

• To develop a multifunctional interface layer for zinc anodes to overcome the limitations of Zn-I₂ batteries.
• To enhance the stability, efficiency, and lifespan of Zn-I₂ batteries through improved zinc anode performance.

Main Methods:

• A core-shell structured InHCF@ZIF-8 (IHZ) material was synthesized using electrostatic self-assembly.
• The IHZ layer was applied to zinc anodes to investigate its effect on zinc deposition and battery performance.
• Symmetric cells and full Zn-I₂ batteries with the modified anode were tested for cycling stability, rate capability, and self-discharge.

Main Results:

• The IHZ layer induced uniform zinc deposition and homogeneous distribution of the electric field and Zn²⁺ flux via a dual coordination mechanism.
• IHZ effectively suppressed zinc dendrite nucleation and growth by directing horizontal zinc deposition and mitigated self-discharge through electrostatic repulsion of I₃^-.
• Symmetric cells achieved an ultralong cycle life of 6490 h, and Zn-I₂ batteries demonstrated a lifespan exceeding 14800 cycles with excellent capacity and rate capability.

Conclusions:

• The developed InHCF@ZIF-8 interface layer is a promising strategy for stabilizing zinc anodes in Zn-I₂ batteries.
• This approach significantly enhances the cycle life, capacity, and rate performance, paving the way for practical applications of high-energy-density zinc batteries.