Electrochemical and thermal properties of NASICON structured Na3V2(PO4)3 as a sodium rechargeable battery cathode: a combined experimental and theoretical study cathode

Abstract

A combined experimental and computational study on Na3V2(PO4)3 has been carried out to investigate its structural, electrochemical, and thermal properties as a sodium battery cathode. The synthesized material by a sol-gel process was well-indexed to the R-3m space group in the framework of a rhombohedral NASICON structure. Galvanostatic measurements indicate that at 3.4 V vs. Na/Na+, 1.4 Na reversibly reacts with each Na3V2(PO4)3, which corresponds to a specific capacity of 84.8 mAh/g. Moreover, this material shows excellent rate capabilities and good cycling performance. Ex-situ XRD analyzes indicate that this material reacts with Na ions based on a reversible two-phase reaction. Thermal analyzes employing TGA/DSC and In-situ XRD at various temperatures show that this material maintains good thermal stability up to 450oC even in the desodiated state. The promising electrochemical and thermal properties suggest that this material with the well-defined NASICON structure is a promising cathode for large-scale sodium rechargeable batteries.