Protective NaSICON Interlayer between a Sodium-Tin Alloy Anode and Sulfide-Based Solid Electrolytes for...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Sodium batteries face challenges with reactive components, particularly the sodium metal anode and sulfide solid electrolytes.
• The interface between the anode and solid electrolyte is prone to chemical instability, hindering battery performance.

Purpose of the Study:

• To introduce a ceramic interlayer, Na3.4Zr2Si2.4P0.6O12, to protect the sulfide solid electrolyte from the reactive sodium metal anode.
• To evaluate the chemical and electrochemical stability of the anode-separator interface with the ceramic interlayer.

Main Methods:

• Impedance spectroscopy to analyze interface stability.
• X-ray photoelectron spectroscopy (XPS) for surface chemical analysis.
• Scanning electron microscopy (SEM) for morphological characterization.

Main Results:

• The Na3.4Zr2Si2.4P0.6O12 interlayer demonstrates chemical stability with both the sodium metal anode and the sulfide solid electrolyte.
• Impedance analysis indicates an electrochemically stable interface.
• SEM reveals a surface reaction between the ceramic and sulfide, which does not negatively impact performance.

Conclusions:

• The Na3.4Zr2Si2.4P0.6O12 interlayer effectively stabilizes the anode-separator interface in sodium batteries.
• This stabilization is a significant step towards realizing stable sodium all-solid-state batteries.
• The use of brittle ceramics in high-pressure sulfide battery systems remains a challenge.