Schottky-Orbital Coupling Drives Ion-Electron Transfer: Triggering Stable Fast-Charging in MnV-Based Phosphate...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Sodium Manganese Vanadium Phosphate (Na4MnV(PO4)3) is a promising cathode material due to its cost-effectiveness and high voltage.
• Practical application is limited by structural distortions during multiple electron transfers and low electronic conductivity.

Purpose of the Study:

• To address the limitations of Na4MnV(PO4)3 by designing a Schottky and 3d-orbital coupling strategy.
• To enhance electrode kinetics and structural stability for improved sodium-ion battery performance.

Main Methods:

• A Schottky and 3d-orbital coupling design paradigm was employed.
• In-situ generation of metallic Ni2P particles in contact with semiconducting phosphate particles.
• Theoretical calculations and experimental validation.

Main Results:

• The developed Schottky-orbital coupling mediated Na4MnV(PO4)3 (SOMV) cathode demonstrated continuous multistep redox and a reversible capacity of 143.9 mAh g-1 at 0.1 C.
• The Ni2P/Na4MnV(PO4)3 interface induced a built-in electric field, facilitating ion-electron transfer.
• Achieved remarkable rate capability (82.5 mAh g-1 at 30 C) and fast-charging performance (88.5 mAh g-1 in 26 s).
• Exhibited excellent long-term cycling stability with 75.0% capacity retention after 10,000 cycles at 30 C.

Conclusions:

• The Schottky and 3d-orbital coupling effectively enhances the electrochemical performance of Na4MnV(PO4)3.
• This synergistic engineering approach provides a universal paradigm for improving ion-electron transfer in battery materials.
• The SOMV cathode represents a significant advancement in sodium-ion battery technology.