摘要
采用固液结合法制备了LiFePO4正极材料。首先以共沉淀法制得了FePO4前驱体,再以葡萄糖作为碳源通过固相碳还原法制得目标产物LiFePO4。运用XRD和SEM对材料进行物理表征,恒流充放电和循环伏安测试对材料的电化学性能进行分析。结果表明,以固液结合法制备的材料结构单一,颗粒微细,粒径分布均匀,振实密度约为1.40g·cm-3,在室温0.1C下材料的放电比容量为156.8mAh·g-1,1.0C下放电比容量为126.2mAh·g-1,样品在1.0C下经过20次循环后,容量为120.4mAh·g-1,其容量保持率为95.4%。该法制备的材料既实现了液相法制备材料形貌可控的优点,又具备了碳还原与碳包覆同时作用的特点,材料的形貌,振实密度,和电化学性能均得到显著改善。
The cathode material LiFePO4 was synthesized via a solid-liquid combination method.The precursor of FePO4 was prepared by co-precipitation method at first, then put glucose as the carbon source, the target product LiFePO4 is prepared by solid carbon reduction method. And the physical properties of the synthesized materials are studied by XRD and SEM, the electrochemical performances are investigated by using galvanostatie charge/discharge tests and cyclic vohammetry. The result shows： the material prepared by solid-liquid combination method has single struture, fine particles,uniform particle size and its tap density is about 1.40g＂ cm3. The discharge specific capacity of the material reaches 156.8 mAh ＂g-~ at 0.1C rate, and 126.2mAh ＂g-~ at 1.0C rate, room temperature. After 20 cycles,the discharge specific capacity is 120.4 mAh .g-1 at 1.0C rate and its capacity retention rate is 95.4%. Not only the prepared material has the advantages of liquid phase that the morphology controllable,but also make carbon reduction and carbon coated work at the same time .This method significantly improves the moroholoav.the tan densitv and the electrochemical properties of the material.
出处
《化学工程师》
CAS
2013年第9期1-4,7,共5页
Chemical Engineer
基金
国家级大学生创新实验项目(12HGG12)
关键词
锂离子电池
正极材料
磷酸铁锂
固液结合法
lithium ion battery
cathode material
lithium iron phosphate
solid-liquid combination method
