Site-Selective Adsorption on ZnF2/Ag Coated Zn for Advanced Aqueous Zinc-Metal Batteries at Low Temperature.

ABSTRACT

Metallic Zn as a promising anode material of aqueous batteries suffers from severe parasitic reactions and notorious dendrite growth. To address these issues, the desolvation and nucleation processes need to be carefully regulated. Herein, Zn foils coated by ZnF2-Ag nanoparticles (ZnF2-Ag@Zn) are used as a model to modulate the desolvation and nucleation processes by hybrid surfaces, where Ag has a strong affinity to Zn adatoms and ZnF2 shows an intense adsorption to H2O. This selective adsorption of different species on ZnF2 and Ag reduces the mutual interference between two species. Therefore, ZnF2-Ag@Zn exhibits the electrochemical performance much better than ZnF2@Zn or Ag@Zn. Even at -40 °C, the full cells using ZnF2-Ag@Zn demonstrate an ultralong lifespan of 5000 cycles with a capacity retention of almost 100%. This work provides new insights to improve the performance of Zn metal batteries, especially at low temperatures.