摘要
本文主要通过水热法制备了锂离子电池正极材料Li3V2-2x／3Mgx（PO4）3／C，并研究了掺杂金属元素Mg对Li3V2（PO4）3晶体结构和电性能的影响。结果表明，当Mg含量x=0．45（质量分数，下同）时，且在温度为750℃焙烧6h的条件下所制备的样品具有较好的晶体结构、微观形貌和电化学性能。镁掺杂量在一定范围内变化不会影响磷酸钒锂本身的单斜结构。在3．0～4．8V、0．1C倍率下，Li3V1.70Mg0.45（PO4）3/C复合材料首次放电比容量高达154．4mAh·g^-1，首次库伦效率为94．32％，在不同倍率下循环25次之后的容量依然可以达到112．8mAh·g^-1。掺杂镁的样品与未掺杂的样品相比，容量和循环倍率性能均有了很大程度的提高。
Cathode material Li3 V2-2x/3Mg, （PO4 ）3/C for lithium-ion batteries was prepared by hydrothermal method, and the effects of the Mg-doping on crystal structure, morphology and electrochemical properties of cathode materials were studied. The results show that the sample with the Mg content of x = 0.45, and prepared at 750 ℃ for 6 h has a better crystal structure, morphology and electrochemical performance. It is also found that adding an appropriate amount of Mg does not change the monoelinic structure of Li3 V2 （PO4 ）3. The initial discharge capacity of Li3V1.70 Mg0.45 （ PO4 ） 3/C composites is up to 154.4 mAh · g^-1 at 3.0 -. 8 V（0. 1 C magnification） , and the first eoulombic efficiency is 94.32%. After charged/discharged at different magnifications for 25 cycles, the sample retains a discharge specific capacity of 112.8 mAh · g^-1 Both capacity and cycle rate capability have been improved obviously compared with the undoped samples.
出处
《粉末冶金技术》
CAS
CSCD
北大核心
2014年第3期167-173,共7页
Powder Metallurgy Technology
基金
国家科技支撑计划(2012BAE06B04)
关键词
锂离子电池
正极材料
磷酸钒锂
掺杂
水热法
lithium ion battery
cathode material
lithium vanadium phosphate
doping
hydrothermal method
作者简介
通信作者：吴茂，讲师，博士。E-mail：wumao@ustb．edu．cn
