湿化学法合成LiNiVO_4纳米粉体及其电化学性能  

Preparation and Electrochemical Property of LiNiVO_4 Nanoparticles Synthesized by a Wet Chemical Method

作　　者：曹丽云[1] 黄剑锋[1] 吴建鹏[1] 张国运[1] 贺海燕[1] 邓飞[1] 马小波[1] 

机构地区：[1]陕西科技大学,陕西咸阳712081

出　　处：《稀有金属材料与工程》2007年第1期117-120,共4页Rare Metal Materials and Engineering

基　　金：陕西科技大学博士科研创新基金(ZX05-3)

摘　　要：以NH4VO3,LiCl2和NiCl2等为原料,以氨水为pH调节剂,采用超声凝胶方法制备了LiNiVO4纳米晶。并采用XRD,TEM,IR,DTA和TG等分析手段对产物进行了表征,通过差热分析对其合成活化能进行了研究。发现在超声功率为300W时,于500℃下保温1h,可以合成10nm左右的LiNiVO4微晶颗粒,其合成活化能为47.7kJ/mol。电化学性能测试结果表明,在0.2mA/cm2充放电流密度和3.0V～4.8V电压范围内,首次充电容量为103mAh/g,放电容量为75mAh/g,循环次数达4次后,放电容量还有62mAh/g,明显优于目前所报道的同类材料。Nanocrystalline of LiNiVO4 was prepared by a wet sono-gel process using NH4VO3, LiC12 and NiCl2 as source material and NH4OH as pH controlling additive. The as-prepared particles were characterized by XRD, TEM, DTA and TG analyses. The synthesis mechanism of LiNiVO4 was investigated by DTA analyses. Results showed that the nanometer LiNiVO4 crystallites with the particle size of about 10 nm could be prepared at 500℃ for 1 h when the ultrasonic sonicating power was kept as 300 W. By DTA analysis, the synthesis activation energy of LiNiVO4 was calculated as 47.7 kJ/mol. Electrochemical property tests indicated that the as-repared LiNiVO4 powder had an initial charge capacity of 103 mAh/g and discharge capacity of 75 mAh/g for charge/discharge current density of 0.2 mA/cm^2 and charge/discharge voltage of 3.0 V-4.8 V. The discharge capacity decayd to 62 mAh/g after 4 cycles, inferring a good cycle stability.

关 键 词：LiNiVO4 纳米颗粒 合成活化能 电化学性能 

分 类 号：O614.111[理学—无机化学]