Eliminating electron localization by molecular array induces uniform zinc deposition enabling stable zinc anode

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Zinc anodes are crucial for rechargeable batteries but suffer from dendrite formation and instability.
• Current electrolyte additives often focus on ion transport, neglecting anode surface regulation.
• Controlling the zinc anode's surface state is key to achieving uniform zinc deposition.

Purpose of the Study:

• To design and investigate vanillin acetate as a functional electrolyte additive for stabilizing zinc metal anodes.
• To elucidate the mechanism by which vanillin acetate regulates zinc anode surface and deposition behavior.
• To evaluate the electrochemical performance of zinc anodes modified with vanillin acetate in symmetrical and full batteries.

Main Methods:

• Design and synthesis of vanillin acetate as an electrolyte additive.
• Electrochemical characterization of zinc anodes using cyclic voltammetry and electrochemical impedance spectroscopy.
• Assembly and testing of Zn||Zn symmetrical cells and NH4V4O10||Zn full cells.
• Analysis of zinc deposition morphology and surface chemistry.

Main Results:

• Vanillin acetate molecules form compact layers on the zinc anode, modulating ion transport and electron distribution.
• The additive promotes uniform Zn2+ deposition, effectively suppressing dendrite formation.
• Zn||Zn symmetrical batteries show extended cycle life over 2000 h and 800 h under different current densities.
• NH4V4O10||Zn full batteries maintain 87.43% capacity after 2000 cycles at a high loading.

Conclusions:

• Vanillin acetate serves as an effective electrolyte additive for stabilizing zinc anodes by regulating surface states.
• This strategy significantly enhances the reversibility and cycle life of zinc metal batteries.
• The findings offer valuable insights for developing high-performance zinc-based energy storage systems.