Rechargeable Sodium-Ion Battery: High-Capacity Ammonium Vanadate Cathode with Enhanced Stability at High Rate

Area of Science:

• Materials Science
• Electrochemistry
• Computational Chemistry

Background:

• Sodium-ion batteries (SIBs) are a promising alternative to lithium-ion batteries due to sodium's abundance.
• Developing high-performance cathode materials is crucial for advancing SIB technology.

Purpose of the Study:

• To evaluate ammonium vanadate as a cathode material for SIBs.
• To investigate the structural and electrochemical properties of NH4V4O10 using density functional theory (DFT) calculations.
• To optimize electrode preparation for enhanced SIB performance.

Main Methods:

• Experimental synthesis and characterization of ammonium vanadate cathode.
• Density functional theory (DFT) calculations for structural and property analysis.
• Electrochemical testing including capacity, cycle life, and rate capability measurements.

Main Results:

• Ammonium vanadate exhibits high capacity (190 mAh g(-1)), long cycle life, and good rate capability.
• DFT calculations predicted sodium arrangements and properties, aligning well with experimental data.
• Carbon-coated ammonium vanadate on Al current collectors showed superior electrochemical performance.

Conclusions:

• Ammonium vanadate is a viable and high-performing cathode material for SIBs.
• The combination of experimental and computational approaches provides valuable insights into material behavior.
• Optimized electrodes demonstrate sustained performance without expensive electrolyte additives.