高密度球形LiFePO_4的合成及性能  

Preparation and characteristic of high-density spherical LiFePO_4

作　　者：雷敏[1] 应皆荣[1] 姜长印[1] 万春荣[1] 

机构地区：[1]清华大学核能与新能源技术研究院,北京102201

出　　处：《电源技术》2006年第1期11-13,共3页Chinese Journal of Power Sources

基　　金：国家自然科学基金资助项目(50002006);清华大学基础研究基金项目(JCqn2005043)

摘　　要：通过控制结晶法制备球形前驱体FePO_4·xH_2O,经过预烧得到高密度的FePO_4,与Li_2CO_3和葡萄糖均匀混合,采用碳热还原法合成锂离子蓄电池正极材料球形磷酸铁锂(LiFePO_4)。用X光衍射和扫描电镜分析对FePO_4和LiFePO_4的结构进行了表征。充放电测试表明LiFePO_4具有3.4V放电电压平台,在0.1mA/cm2电流密度条件下,首次充电比容量为146.9mAh/g,放电比容量为129.7mAh/g。该球形LiFePO4粉末的振实密度高达1.8g/cm3,首次放电比容量高达233.5mAh/cm3,远高于一般非球形LiFePO_4正极材料。The high-density spherical FePO4 powders were obtained by pre-heatiog treatment of the FePO4·xH2O powders which wore prepared using a “controlled crystallization” method. The LiFoPO4 were synthesized by means or carbonthermal reduction method, sintering the FePO4 precursor and Li2CO3 and glucose in inert atmosphere. The FePO4 and LiFePO4 structure were characterized by XRD and SEM. Electrochomical tests of the charge-disctharge process show that the spherical LiFePO4 cathode material has 3.4V flat voltage discharge profile. The cathode material had an initial charge capacity of 146.9 mAh/g and a discharge capacity of 120.7 mAh/g. The product olivilae LiFePO4 has high tap-dcnsity of 1.8 g/cm^3 and high energy.density of 233.5 mAh/cm^3, which is remarkably higher than non-spherical LiFePO4 products.

关 键 词：锂离子蓄电池 正极材料 LIFEPO4 高密度 球形 控制结晶法 

分 类 号：TM912.9[电气工程—电力电子与电力传动]