Preparation of Na₃V₂（PO₄）₃ Cathode Material for Sodium Ion Batteries by Sol-gel Method

In order to develop Na₃V₂（PO₄）₃（NVP） cathodes with high performance for sodium ion batteries,a modified carbon-coated NVP was synthesized by sol-gel method.The crystal structure and phase analysis of the samples were carried out by X-ray diffraction（XRD）.The spectral characteristics and group compositions,the apparent morphology and particle size,and the carbon content of the materials obtained were analyzed using Fourier transform infrared spectroscopy（FTIR）,scanning electron microscopy（SEM） and thermogravimetric analyzer（TGA）,respectively.The electrochemical properties of the samples were evaluated by charge and discharge test instrument.The results show that the NVP particles have a size of 1~3 μm with amorphous carbon coated on the surface（NVP/C）.It exhibits 110 m Ah/g of initial discharge capacity at 2.5~3.8 V of voltage range and 1 C of rate,which is 93.5% of the theoretical capacity.In addition,the NVP/C could still release a capacity of 54 m Ah/g at 50 C,indicating an excellent rate capability.