摘要
以柠檬酸作为分散剂,采用胶凝胶法制备锂离子电池正极材料磷酸铁锂,采用X射线衍射光谱法(XRD),扫描电子显微镜法(SEM)和电化学手段对目标材料进行了结构表征和性能测试。考察了碳改性过程中蔗糖加入量、后期煅烧时间及金属离子Zr4+掺杂改性对合成材料充放电性能的影响。结果表明,合成产物为橄榄石型磷酸亚铁锂,碳改性和Zr4+离子能有效控制颗粒长大,提升材料的电化学性能;加入60%蔗糖,掺杂锆离子,650℃烧结18 h制备的磷酸亚铁锂的可逆性好,0.2C放电比容量达到162 mAh·g-1。
Doped LiFePO4 cathode material for lithium batteries was prepared by sol-gel method using citric acid as dispersing agent.The crystal stucture and electrochemical performance were characterized by XRD,SEM and electrochemical performance test.The effects of amount of sucrose in carbon modification process,post-calcination time and the metal ions Zr4＋ doped charge-discharge on the performance of LiFePO4/C cathode material were investigated and the causes were also analyzed.The results demonstrated that the product was the olivine-type lithium iron phosphate,carbon modification and Zr4＋ ions could effectively control the grain growth,improved the electrochemical properties of the material.The sample exhibited a capacity of 162 mAh·g-1 at 0.2C rate and good reversibility when they were prepared by adding 60 % sucrose,sintering at 650 ℃ for 18 h.
出处
《广东化工》
CAS
2012年第11期69-70,42,共3页
Guangdong Chemical Industry
基金
中山市科技局课题(20103A276)
关键词
磷酸铁锂
电化学性能
溶胶凝胶
lithium iron phosphate
electrochemical properties
sol-gel
