A Na(+) Superionic Conductor for Room-Temperature Sodium Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Chemistry

Background:

• Lithium-ion batteries dominate electronics and energy storage but face lithium availability challenges.
• Sodium-based batteries offer a low-cost alternative with potential for all-solid-state designs.
• Developing solid electrolytes with high room-temperature ionic conductivity is crucial for solid-state battery success.

Purpose of the Study:

• To discover and characterize a new sodium superionic conductor for all-solid-state sodium batteries.
• To evaluate the ionic conductivity of the novel material at room temperature.
• To demonstrate the feasibility of a solid-state sodium-sulfur cell using the developed conductor.

Main Methods:

• Synthesis of a novel sodium superionic conductor with a NASICON structure (Na3.1Zr1.95Mg0.05Si2PO12).
• Measurement of ionic conductivity at room temperature.
• Fabrication and testing of a room-temperature solid-state sodium-sulfur cell.

Main Results:

• The synthesized material, Na3.1Zr1.95Mg0.05Si2PO12, exhibits a high room-temperature ionic conductivity of 3.5 × 10⁻³ S cm⁻¹.
• Successful fabrication of a functional room-temperature solid-state sodium-sulfur cell was achieved.
• The novel conductor demonstrates suitability for all-solid-state sodium battery applications.

Conclusions:

• A novel sodium superionic conductor with NASICON structure has been identified.
• The material possesses high ionic conductivity, essential for solid-state electrolytes.
• This development represents a significant step towards practical all-solid-state sodium batteries.