Research on Controllable Synthesis and Growth Mechanism of Sodium Vanadium Fluorophosphate Nanosheets.

Abstract

Background: Sodium vanadium fluorophosphate is a sodium ion superconductor material with high sodium ion mobility and excellent cyclic stability, making it a promising cathode material for sodium-ion batteries. However, most of the literature and patents report preparation through traditional methods, which involve complex processes, large particle sizes, and low electronic conductivity, thereby limiting development progress.

Objective: Aiming at the limitation of high cost and poor performance of vanadium sodium fluorophosphate cathode material, the low temperature and high-efficiency nano preparation technology was developed.

Methods: This study uses a homogenizer with high dispersion and shear force to directionally control the collision of sodium vanadium fluorophosphate nanoparticles with higher specific surface energy during the initial nucleation stage, forming nanosheet structures.

Results: The growth mechanism of these nanosheets was analyzed using SEM, XRD, AFM, and DFT simulation. Results indicate that the crystal surfaces with higher surface energy undergo directional collisions in the early nucleation stage, gradually reducing the surface energy and stabilizing the system, resulting in sodium vanadium fluorophosphate nanosheets.

Conclusion: Due to the larger specific surface area and pore structure, these nanosheets exhibit excellent rate performance and cycle stability, making them suitable for application and promotion in the field of fast-charging energy storage.