热处理温度对LiMnPO_(4)/C复合纳米纤维电化学性能的影响  

Effects of different heat treatment temperatures on the electrochemical properties of LiMnPO_(4)/C nanofibers

作　　者：张凯[1] 鲜小红[2] 江奥 ZHANG Kai;XIAN Xiao-hong;JIANG Ao(Department of Architecture and Environmental Engineering,Sichuan Vocational Technical College,Suining 629000,China;Department of Mechanical Engineering,Sichuan Vocational Technical College,Suining 629000,China;College of Materials and Chemistry and Chemical Engineering,Chengdu University of Technology,Chengdu 610059,China)

机构地区：[1]四川职业技术学院建筑与环境工程系,四川遂宁629000 [2]四川职业技术学院机械工程系,四川遂宁629000 [3]成都理工大学材料与化学化工学院,四川成都610059

出　　处：《化学研究与应用》2021年第6期1186-1191,共6页Chemical Research and Application

基　　金：四川省教育厅自然科学基金重点项目(18ZA0430)。

摘　　要：以乙酸锂、乙酸锰、浓磷酸和PVP为原料,采用静电纺丝法制备了LiMnPO_(4)/C纳米纤维锂离子电池正极材料,并研究了煅烧温度对LiMnPO_(4)/C纳米纤维样品形貌、结构和电化学性能的影响。通过X射线粉末衍射(XRD)和扫描电子显微镜(SEM)对其样品进行了结构和形貌表征。结果表明,经700℃焙烧的LiMnPO_(4)/C样品为橄榄石型结构,在SEM下呈直径约为310 nm纤维状。该样品在室温0.2 C倍率下首次放电比容量可达157.3 mAh·g^(-1),循环1000圈后的放电比容量在150 mAh·g^(-1)左右,容量保有率为95.3%,具有较高的循环稳定性。The LiMnPO_(4)/C nanofibers were successfully synthesized by electrospinning at different calcination temperatures.The effect of calcination temperatures on the performance of LiMnPO_(4)was systematically investigated using X-ray diffraction,charge/discharge measurements,cyclic voltammetry and electrochemical impedance spectroscopy tests.The SEM images shows that the LiMnPO_(4)/C sample calcined at 700°C is in the shape of fibers with a diameter of 310 nm.The change of temperature affects the number of lithium ion diffusion pathways and free charges in the LiMnPO_(4)structure.The results suggest that LiMnPO_(4)materials with calcined at 700°C show a high discharge capacity with 157.3,131.8,108.5 and 92 mAh·g^(-1) at 0.2,1,5 and 10 C,and a capacity retention of around 95.3%after 1000 cycles at 0.2 C.

关 键 词：正极材料 纳米纤维 LiMnPO_(4) 静电纺丝法 电化学性能 

分 类 号：O614.1[理学—无机化学]