Engineered Crystalline Heterostructure Interphase Enabling Dendrite-Free Sodium Metal Anodes with Long-Term Stability

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Sodium-ion batteries (SIBs) are promising for energy storage.
• Stable sodium metal anodes (SMAs) are crucial for SIB advancement.
• Dendritic growth and uneven plating hinder SMA practical use.

Purpose of the Study:

• To design a stable artificial interphase for sodium metal anodes.
• To address dendrite formation and improve Na stripping/plating.
• To enhance the performance of sodium-ion batteries.

Main Methods:

• Fabrication of a triphasic heterojunction artificial interphase via in situ reaction of Ag3PO4 and sodium metal.
• Characterization of the Ag2Na/Ag/Na3PO4 interphase composition and structure.
• Electrochemical testing of symmetric and full cells with the engineered anode.

Main Results:

• The Ag2Na/Ag/Na3PO4 interphase effectively regulated ion transport and suppressed dendrites.
• The Na/Ag3PO4 anode showed low nucleation overpotential (27 mV) and stable cycling (>1600 h).
• A full pouch cell achieved high energy density (425.5 Wh kg-1).

Conclusions:

• The triphasic heterojunction artificial interphase is a viable strategy for stable SMAs.
• This interfacial engineering enhances ionic conductivity and electronic conductivity.
• The developed anode shows significant potential for high-energy SIBs.