Monolithic Phosphate Interphase for Highly Reversible and Stable Zn Metal Anode.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Zinc metal batteries (ZMBs) are a promising next-generation energy storage technology.
• Practical application of ZMBs is hindered by zinc anode dendrites and corrosion.
• Stabilizing the zinc anode is critical for improving battery performance and lifespan.

Purpose of the Study:

• To develop a method for creating a stable monolithic solid-electrolyte interphase (SEI) on zinc anodes.
• To investigate the use of dimethyl methylphosphonate (DMMP) as a high dipole moment solvent for SEI formation.
• To enhance the cycling stability and Coulombic efficiency of zinc metal anodes.

Main Methods:

• A controlled electrolytic method was employed using DMMP-based electrolytes.
• A homogeneous and robust phosphate SEI (Zn3(PO4)2 and ZnP2O6) was formed in situ.
• Electrochemical performance was evaluated using Zn|Zn, Zn|Cu, and V2O5|Zn cells.

Main Results:

• The DMMP-derived SEI effectively stabilized the zinc anode, preventing dendrites and corrosion.
• The zinc electrode demonstrated long-term cycling of 4700 hours and 99.89% Coulombic efficiency in Zn|Cu cells.
• Full V2O5|Zn batteries with a DMMP-H2O hybrid electrolyte retained 82.2% capacity after 4000 cycles at 5 A g-1.

Conclusions:

• The successful construction of a monolithic phosphate SEI provides a new strategy for stabilizing zinc metal anodes.
• This approach opens new avenues for electrolyte design in developing highly reversible and stable ZMBs.
• The findings pave the way for practical and efficient zinc metal battery applications.