LiFePO_4锂电池正极材料的Li_(0.5)La_(0.5)TiO_3包覆改性  

Li_(0.5)La_(0.5)TiO_3 Coating for LiFePO_4 Cathode Material of Li-ion Battery

作　　者：高亮 张敏刚[1] 郝豫宝 闫时建[1] 郭锦 李英杰[1] GAO Liang;ZHANG Min-gang;HAO Yu-bao;YAN Shi-jian;GUO Jin;LI Ying-jie(Taiyuan University of Science and Technology,Taiyuan 030024,China)

机构地区：[1]太原科技大学,太原030024

出　　处：《太原科技大学学报》2018年第4期281-287,共7页Journal of Taiyuan University of Science and Technology

基　　金：山西省科技平台建设项目(2015091011);晋城市科技计划项目(201501004-21);太原市科技计划项(110153)

摘　　要：研究了以快离子导体Li_(0.5)La_(0.5)TiO_3(LLTO)包覆的LiFePO_4正极材料的锂离子电池的电化学性能。采用溶剂热法制备锂电池正极材料LiFePO_4,再采用溶胶凝胶法制备的LLTO粉体对LiFePO_4进行包覆,包覆量为LiFePO_4质量分数的1%~4%.通过进行充放电测试、交流阻抗测试及循环伏安测试,研究了不同包覆量对电池的充放电比容量、循环性能及可逆性的影响。发现当LLTO含量为3 wt%,2 C、5 C时,充放电时相对于没有包覆LLTO的电池正极材料的比容量分别提高29.7%、31.6%,30次循环之后,容量损失率减小4.13%,循环伏安曲线上氧化还原峰之间的电位差仅为0.117 V,以3 wt%的LLTO包覆改性LiFePO_4显著提高了电池的电化学性能。The cathode material LiFePO4 was coated with fast ionic conductor Li0.5La0.5TiO3（LLTO）to investigate the electrochemical properties of Li-ion battery. LiFePO4 was synthesized via solvothermal route,and LLTO powder was synthesized via sol-gel route,then LiFePO4 was coated by LLTO with the LLTO proportion of 1 wt% ~ 4 wt%.The effects of LLTO coating proportion on discharge specific capacity,cycle performance and reversibility were studied by charge/discharge test,AC impedance test and cyclic voltammetry test. The results indicate that when LLTO coating proportion is 3 wt%,the specific capacity increases by 29. 7 % in the current rate of 2 C and increases by 31. 6 % in the current rate of 5 C,the capacity loss rate after 30 charge/discharge cycles decreases by 4.13%,and the potential difference between redox peaks in cyclic voltammetry curve is only 0. 117 V. LLTO coating LiFePO4 with proportion of 3 wt% significantly improves electrochemical properties of Li-ion battery.

关 键 词：锂离子电池 LIFEPO4 Li0.5La0.5TiO3 表面包覆 

分 类 号：TM912[电气工程—电力电子与电力传动]