Low-Temperature Brazing Strategy for High Voltage Na₄MnCr(PO₄)₃ Cathode-Based Solid-State Sodium-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• All-solid-state sodium-ion batteries (ASSIBs) offer enhanced safety and energy density potential.
• High-voltage cathodes in ASSIBs face challenges with slow charge transfer and chemical instability at the cathode-electrolyte interface.

Purpose of the Study:

• To achieve high energy density in Na4MnCr(PO4)3-based ASSIBs.
• To overcome interface limitations between high-voltage cathodes and solid electrolytes.
• To develop a simple and effective strategy for improving ASSIB performance.

Main Methods:

• A simple low-temperature brazing strategy was employed.
• In situ generation of a secondary phase at the cathode-electrolyte interface.
• Characterization of Na4MnCr(PO4)3-based ASSIBs.

Main Results:

• High energy density ASSIBs were successfully fabricated using Na4MnCr(PO4)3.
• The in situ generated secondary phase facilitated close contact and rapid charge transfer.
• Interface side reactions were effectively reduced by modifying the interface electric field.

Conclusions:

• The low-temperature brazing strategy enables high-performance Na4MnCr(PO4)3-based ASSIBs.
• This approach significantly improves interfacial properties, addressing key limitations in ASSIB development.
• The strategy offers valuable insights for advancing other high-energy all-solid-state battery technologies.