ИСТИНА

The expanding demand for electric vehicles has quadrupled the price of lithium since 2014. This led to a great interest to sodium-ion batteries, which are cheaper. Chemical similarity of lithium to sodium allows using it in rechargeable batteries. Thus, the up-to-date challenge is to obtain high energy density material, which can be used for industrial applications. One of the promising cathode materials Na3V2(PO4)3 with NASICON structure has attracted much attention to sodium-ion batteries among various cathode materials because of its high theoretical energy and power density and excellent thermal stability. [1].The NASICON structure features a highly covalent three-dimensional framework that generates large interstitial spaces which sodium ions may rapidly diffuse through. Carbon-coated Na3V2(PO4)3 electrodes show flat plateaus at 3.4 and 1.6 vs. Na+/Na. Discharge capacities in these cases correspond to 2 and 1 Na ions per formula respectively. The replacement of one vanadium with different metals, more often on transition metals, shows increase of amount intercalation sodium in structure, as in case with Mn2+/Mn3+ but with low stability cycling. Another problem of previously reviewed NASICON materials is dissymmetry of charge/discharge curve.