溶胶-凝胶法制备LiFePO_4粉体及其电化学性能研究  

Preparation and Electrochemical Properties of LiFePO_4 Powder Prepared by Sol-gel Method

作　　者：吴朝阳[1] 赵胜利[1] 孙为[1] 

机构地区：[1]河南科技大学材料学院,河南洛阳471003

出　　处：《热加工工艺》2013年第10期60-62,66,共4页Hot Working Technology

基　　金：国家自然科学基金项目(20203006);河南省教育厅自然科学计划项目(2006430005);国家重大基础研究计划项目(ZM200103B01);河南科技大学人才科研基金项目(04015)

摘　　要：通过溶胶-凝胶法并结合热处理工艺制备LiFePO4粉体,采用XRD、SEM及恒电流充放电技术等方法,研究了煅烧时间对LiFePO4粉体结构、形貌及电化学性能的影响。结果表明:以聚丙烯酸(PAA)、硝酸铁、硝酸锂和磷酸二氢铵为原料,在一定温度下合成了稳定的溶胶和凝胶,经650℃煅烧得到LiFePO4粉体。随着煅烧时间的延长,粉体颗粒逐渐增大,晶型趋于完整;煅烧16 h获得的LiFePO4颗粒大小均匀,晶型完整且没有明显团聚现象。1C倍率下首次放比电容量达到140 mAh/g,经100次循环后仍高于130 mAh/g,容量保持率高达93%,表现出良好的充放电稳定性。LiFePO4 powder was synthesized by sol-gel and heating treatment process. The influences of sintering time on the mierostrueture, morphology and electrochemical performance were explored by XRD, SEM and galvanostatic charge-discharge. The results show that the stable sol and gel were prepared by PAA, FeNO3, LiNO3 and NH4H2PO4 in water solution. The LiFePO4 can be obtained under sintering at 650 ℃. With the increase of calcination time, LiFePO4 particle becomes larger and the crystal structure is more integrity. The LiFePO4 powder prepared by heating treatment gel at 650 ℃ for 16 h exhibits uniform distribution, high crystallinity, low agglomeration and high electrochemistry performance. The first discharge capacity reaches 140 mAh/g at the rate of 1C, and the capacity remains 130 mAh/g after 100 cycles. The capacity retention ratio reaches 93%, which can prove that LiFePO4 has stable cycle performance.

关 键 词：LIFEPO4 结构 溶胶-凝胶 电化学性能 

分 类 号：TB383[一般工业技术—材料科学与工程]