纳米磷酸铁锂的制备及电化学性能研究

利用液相沉淀法合成了纳米级磷酸铁,并以此为铁源,通过碳热还原技术制备了粒径均匀的纳米级球形LiFePO4/C正极材料。经热分析(TG-DSC)、X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)以及恒电流充放电测试,研究了纳米磷酸铁及纳米磷酸铁锂材料的结构、形貌以及电化学性能。实验结果表明材料的首次放电比容量达161.8 mAh.g-1(0.1C),库仑效率为98.3%;室温下在0.2C、0.5C、1C、2C及5C倍率充放电其首次放电比容量分别为156.5、144、138.9、125.6和105.7 mAh·g-1,材料具有较好的倍率性能。

Preparation and Electrochemical Properties of Nano-Sized LiFePO4/C

Nano-sized FePO4 was syhthesized by liquid precipitation,and uniform spherical nano-sized LiFePO4/C cathode material was prepared through Carbothermal reduction technology with nano-sized FePO4 as Iron source.The nano-sized FePO4 and nano-sized LiFePO4/C samples were characterized by TG-DSC,XRD,SEM,TEM and galvanostatic charge-discharge test.The results show that the initial discharge specific capacities of the nano-sized LiFePO4/C reach to 161.8 mAh·g-1 at 0.1C rate with coulombic efficiency of 98.3%.At room temperature,the sample delivers initial discharge capacity of 156.5,144,138.9,125.6 and 105.7 mAh·g-1 at 0.2C,0.5C,1C,2C and 5C rates(1C=150 mA·g-1),respectively.The material exhibits excellent rate performance.