Material Optimization Engineering toward xLiFePO₄·yLi₃V₂(PO₄)₃ Composites in Application-Oriented Li-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium iron phosphate (LFP) exhibits slow Li-ion diffusion kinetics, limiting its use in high-power energy storage.
• Vanadium substitution in LFP is explored to improve power capacity and overall battery performance.

Purpose of the Study:

• To fabricate and optimize xLiFePO₄·yLi₃V₂(PO₄)₃ (xLFP·yLVP) composite electrode materials.
• To evaluate the electrochemical performance and potential of the 5LFP·LVP composite for Li-ion batteries.

Main Methods:

• Fabrication of xLFP·yLVP composites using a spray-drying method.
• Characterization of material properties including energy density and compacted density.
• Electrochemical testing of 5LFP·LVP||LTO Li-ion pouch cells under various current loads and cycling conditions.

Main Results:

• The 5LFP·LVP composite demonstrated excellent Li-ion storage capacity (413.6 W·h·kg^-1) and machining capability (1.82 g·cm^-3).
• The 5LFP·LVP||LTO pouch cell retained 75% capacity after 300 cycles at 400 mA with high Coulombic efficiency.
• Significant capacity retention (60.3%) was observed at 1200 mA after 300 cycles, with a low fading rate of 0.15% per cycle.

Conclusions:

• The 5LFP·LVP composite is identified as an optimal material for enhancing Li-ion battery performance.
• The developed composite offers a promising pathway for application-oriented Li-ion batteries with improved energy storage capabilities.
• This study provides a scientific basis for the accelerated development of xLFP·yLVP composites.