溶胶—凝胶法制备钠离子电池正极材料Na3V2（PO4）3

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

为了探究制备优异性能的钠离子电池正极材料Na3V2（PO4）3（NVP）,利用溶胶—凝胶法合成了一种新型改性的碳包覆的磷酸钒钠复合材料。利用X射线衍射（XRD）对样品进行了晶体结构和物相分析;使用傅里叶红外光谱（FTIR）对样品的谱学性质和基团成分进行了分析;采用扫描电镜（SEM）对样品的表观形貌和粒度进行了表征;利用热重分析仪（TGA）对样品的含碳量进行了检测;采用充放电测试系统对材料电化学性能进行了评价。结果显示,样品NVP颗粒大小在13μm且表面被无定形碳包覆（NVP/C）;在2.53.8 V电压范围内1 C倍率下的首次放电容量为110 m Ah/g,为理论容量的93.5%。此外,样品NVP/C在50 C倍率下释放的容量为54m Ah/g,表现出优异的倍率性能。

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 13 μm with amorphous carbon coated on the surface（NVP/C）.It exhibits 110 m Ah/g of initial discharge capacity at 2.53.8 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.