Hofmeister Effect-Induced Hydrogel Interphase Engineering for Highly Stable Zn Metal Anodes

Area of Science:

• Materials Science
• Electrochemistry
• Chemical Engineering

Background:

• Zinc battery commercialization is hindered by zinc anode instability, specifically dendrite growth and parasitic reactions.
• Developing stable zinc anodes is crucial for advancing aqueous energy storage systems.

Purpose of the Study:

• To engineer a stable zinc anode interface using the Hofmeister effect.
• To synergistically stabilize zinc deposition and suppress side reactions for improved battery performance.

Main Methods:

• Utilized kosmotropic anions to induce ion-specific "salting-out" effects.
• Constructed a compact hydrogel protective layer via ion enrichment and polymer reorganization.
• Applied interfacial engineering to 3D laser-textured Zn electrodes.

Main Results:

• Achieved enhanced adhesion, suppressed hydrogen evolution, and regulated Zn²⁺ transport.
• Optimized anode demonstrated elevated hydrogen evolution overpotential and reduced corrosion current density (1.67 mA cm^-2).
• Zn||Zn symmetric cells operated stably for over 4500 h; Zn||I₂ full cells showed high capacity (∼198 mAh g^-1) with 92.9% retention after 4500 cycles.

Conclusions:

• Hofmeister-effect-regulated interfacial engineering effectively mitigates kinetic limitations and dendrite formation in zinc anodes.
• The strategy offers a robust approach for developing durable, high-performance aqueous energy storage systems.
• Synergistic integration of interfacial engineering and surface morphology optimization is key for advanced battery technology.