摘要
采用水热法制备纳米片状钛酸锂前驱体,再经煅烧制备纳米片状钛酸锂。分别研究了在不同的水热时间(0,1,3,7和14 h)下制备钛酸锂前驱体,再将前驱体在不同温度(350,500和700℃)下煅烧对产物钛酸锂性能的影响。通过SEM、TEM、XRD等表征了产物的结构和形貌,最终产物为含有微量TiO2的尖晶石型纳米片状钛酸锂Li4 Ti5 O12(LTO),很好地继承了前驱体的形貌。将钛酸锂组装成锂离子半电池测试其电池性能,结果表明当水热时间7 h制备的前驱体再经500℃煅烧2 h后,所得到的钛酸锂在0.5C(1C=175 mA/g)下首次放电比容量高达174.6 mAh/g;在20C下的放电比容量为144.1 mAh/g,仍保持为0.5C条件下的82.5%,在20C下进行循环测试,500次后容量保持率为94.6%,说明制备的纳米片状钛酸锂具有良好的倍率性能和循环寿命。
Nanosheet lithium titanate precursor was prepared by hydrothermal method,and then calcined to prepare nanosheet lithium titanate.In this work,the effects of different hydrothermal time(0,1,3,7 and 14 h)of the lithium titanate precursor and different calcination temperatures(350,500 and 700℃)during the preparation of the precursor were studied,respectively.The structures of the products were investigated by scanning electron microscope(SEM),transmission electron microscope(TEM)and X-ray diffraction(XRD),while the electrochemical properties were explored by assembling them into half-coin cells.The phases of all samples are spineltype Li4Ti5O12(LTO)with trace of TiO2.The morphology of the nanosheet precursor is also inherited to Li4Ti5O12(LTO).When the precursor is prepared by the hydrothermal method for 7 h and calcined at 500℃for 2 h,the first discharge specific capacity of the obtained LTO is 174.6 mAh/g at 0.5C(1C=175 mA/g)and the discharge capacity is 144.1 mAh/g with the capacity retention of 94.6%after 500 cycles at 20C,which indicates a superior rate performance of the nanosheet LTO.
作者
冯言华
张祥昕
林长新
薛熙来
陈素晶
张易宁
FENG Yanhua;ZHANG Xiangxin;LIN Changxin;XUE Xilai;CHEN Sujing;ZHANG Yining(College of Chemical Engineering,Fuzhou University,Fuzhou 350000,China;Key Laboratory of Optoelectronic Materials Chemistry and Physics,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences,Fuzhou 350002,China)
出处
《电子元件与材料》
CAS
CSCD
北大核心
2020年第11期33-39,共7页
Electronic Components And Materials
基金
中国科学院洁净能源创新研究院合作基金项目(DNL180308)
福建省引导性项目(2018H0042)
福建省STS计划配套项目(2019T3017)。
关键词
水热法
纳米片状
钛酸锂
锂离子电池
hydrothermal method
nanosheet
lithium titanate(LTO)
lithium ion battery
