锂离子电池LiFePO_4/C复合正极材料的合成及表征  

Synthesis and Characterization of LiFePO_4/C Composite Cathode Material for Lithium-ion Battery

作　　者：韩恩山[1] 冯智辉[1] 魏子海[1] 许寒[1] 

机构地区：[1]河北工业大学化工学院应用化学系,天津300130

出　　处：《精细石油化工进展》2007年第12期1-4,8,共5页Advances in Fine Petrochemicals

摘　　要：以葡萄糖为碳源,采用共沉淀法合成了橄榄石型LiFePO_4/C复合正极材料。利用X射线衍射、原子吸收、扫描电镜以及电化学测试等方法对合成材料进行了结构表征和性能测试。结果表明,在pH值为8时,在较宽温度范围内,LiFePO_4都能形成单一的橄榄石型晶体结构,碳的加入使LiFePO_4/C颗粒粒径减小并大大提高了放电比容量和循环性能。其中在650℃下焙烧制得的产物结构完整,表面形貌较好,粒径分布均匀。在室温及0.05 C倍率下,合成材料的首次放电比容量为161.2 mAh/g,循环10次后,未见明显衰减;当电流加倍时仍表现出良好的循环性能。Olivine - type LiFePO4/C composite cathode materials were synthesized with glucose as carbon source by co- precipitation method. The crystal structure and the electrochemical performance were characterized by XRD, AAS, SEM, and electrochemical performance testing. The results showed that LiFePO4 was single phase olivine - type structure within wide temperatures under pH 8 .The addition of the carbon reduced the LiFePO4/C particle size and enhanced greatly discharge capacity and cycle performance. The material calcined at 650℃ had a complete olivine structure, uniform surface morphology, better particle - size distribution.The initial discharge capacity was 161.2 mAh/g at room temperature and 0.05 C charge- discharge rate. There was no obvious capacity fading after 10 cycles. The LiFePO4/C had excellent cycle performance even at 0.1 C rate.

关 键 词：锂离子电池 复合正极材料 共沉淀法 

分 类 号：TM912[电气工程—电力电子与电力传动]