Facile Synthesis of a Common Na-Ion Battery Cathode Material Na3V2(PO4)2F3 by Spark Plasma Sintering

Abstract

In the pursuit of facile, fast, and efficient methods for the synthesis of various compounds for a variety of applications, spark plasma sintering (SPS) technique is considered to be a powerful and simple tool. Using this technique, a popular cathode material for Na-ion batteries—Na3V2(PO4)2F3—is synthesized and characterized with X-ray diffraction and scanning electron microscopy (SEM), and is electrochemically tested in Swagelok-type cells in a galvanostatic mode. The obtained material is compared with the conventionally synthesized (via a solid-state route) sample. SEM analysis shows 2 times smaller particles in the case of SPS-synthesized material compared with the solid-state-synthesized material which is to be expected from the fast (40 min in total) SPS synthesis that practically excludes grain/particle growth and promotes much faster diffusion, thereby drastically enhancing the reaction kinetics. Electrochemical performance of the SPS-obtained material shows an improvement in decreasing the overpotential and reducing the capacity loss at high C-rates (8C).