Nucleophilic Substitution Enables Robust Fluorinated Interphase for Low N/P Ratio Zinc Battery

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Aqueous zinc (Zn) batteries are attractive for energy storage due to their safety and sustainability.
• Key challenges hindering commercialization include limited Zn reversibility, electrolyte decomposition, and dendritic growth.

Purpose of the Study:

• To develop a novel chemical strategy to enhance Zn anode stability in aqueous batteries.
• To improve Zn reversibility and cycling performance by preventing electrolyte decomposition and dendrite formation.

Main Methods:

• Utilizing nucleophilic ethoxide ions to induce in situ defluorination of trifluoromethanesulfonate anions.
• Forming a protective fluorinated interphase on the Zn anode surface.
• Evaluating the performance of Zn0.25V2O5/Zn powder batteries with the modified anode.

Main Results:

• The engineered fluorinated interphase demonstrated significant mechanical robustness.
• Substantially improved Zn Coulombic efficiency at various current densities and high Zn utilization rates were observed.
• The modified batteries achieved unprecedented cycling stability, even under demanding low N/P ratios and high areal capacity.

Conclusions:

• The proposed in situ surface modification strategy effectively enhances Zn anode reversibility and stability.
• This approach offers a promising pathway for the commercialization of safe and sustainable aqueous zinc batteries.
• The engineered interphase provides a robust solution to electrolyte decomposition and dendritic growth issues.