球形TiNb_(2)O_(7)的固相法制备和嵌脱锂离子性能研究

Preparation and Li+Intercalation/Deintercalation Performance of Spherical TiNb_(2)O_(7) by Solid-Phase Method

通过湿法研磨和喷雾干燥法制备球形前驱体,采用高温固相法合成球形TiNb_(2)O_(7)材料,并对其进行XRD、SEM表征和电化学性能测试。结果表明,制备的TiNb_(2)O_(7)是由一次颗粒组成的二次球形颗粒,平均粒径约4~6μm,内部存在大量孔隙;以0.1 C在0.8~3.0 V电压下充放电,球形TiNb_(2)O_(7)材料首次放电比容量为316.5 mA·h/g,首次库伦效率为99.7%,1 C倍率下经过100次循环后,容量保持率为82.0%,10 C倍率下的放电比容量为234.7 mA·h/g,具有良好的倍率性能。

The precursor of spherical TiNb_(2)O_(7) was prepared by wet grinding process and spray drying process.The TiNb_(2)O_(7) materials were synthesized by the solid-phase method and characterized by XRD,SEM and electrochemical tests.The results showed that the TiNb_(2)O_(7) materials were secondary particles composed of primary particles with an average size of about 4-6mm and numerous pores inside.The TiNb_(2)O_(7) materials exhibited a high initial specific discharge capacity of 316.5 mA·h/g at 0.1 C rate in 0.8-3.0 V with an initial Coulombic efficiency of 99.7%.Furthermore,TiNb_(2)O_(7) had a good rate capacity,which still reached 82.0%after 100 cycles at 1 C,and had a specific discharge capacity of 234.7 mA·h/g at 10 C.