锂离子电池正极材料LiMn_(1.95)Mg_(0.05)O_(3.9)F_(0.1)的制备及其性能研究  

Synthesis and performance study of LiMn_(1.95)Mg_(0.05)O_(3.9)F_(0.1) lithium ion battery anode material

作　　者：刘奇琳[1] 胡启山[2] Liu Qilin Hu Oishan(College of Tea and Food, Wuyi University,Wuyishan 354300 School of Chemistry and Chemical Engineering, Sichuan University of Arts and Science, Dazhou 635000)

机构地区：[1]武夷学院茶与食品学院,武夷山354300 [2]四川文理学院化学与工程技术学院,达州635000

出　　处：《化工新型材料》2016年第12期170-173,共4页New Chemical Materials

基　　金：达州市科技局项目(2013(5);KJJ2015002)

摘　　要：通过固相法制备出锂离子电池正极材料LiMn_2O_4和LiMn_(1.95)Mg_(0.05)O_(3.9)F_(0.1)样品,并通过XRD、SEM、EDS、充放电测试、CV和EIS对其结构、形貌以及电化学性能进行了研究。结果发现,适量Mg、F的掺杂未改变LiMn_2O_4的尖晶石结构。在0.2C倍率下,样品LiMn_2O_4和LiMn_(1.95)Mg_(0.05)O_(3.9)F_(0.1)的首次放电比容量分别为121.3mAh/g和123.7mAh/g,循环60次后,容量保持率分别为82.1%和91.4%。在5C倍率下,样品LiMn_(1.95)Mg_(0.05)O_(3.9)F_(0.1)的放电比容量为92.4mAh/g,而LiMn_2O_4的放电比容量仅为76.5mAh/g。Mg、F的共同掺杂,可以有效抑制锰酸锂晶体中JahnTeller效应导致的结构畸变,稳定尖晶石结构,明显改善其循环稳定性和倍率性能,并提高材料的初始放电比容量。The lithium-ion battery anode material spinel LiMn2O4 and LiMn1.95 Mg0.05O3.9 F0.1 samples was synthe- sized by solid state reaction route. The effects of aluminum and fluorine co-doping on the structure, morphology and electro chemical performance of material were studied by XRD, SEM, EDS,galvanostatic charge discharge,CV and EIS respective- ly. It was found that appropriate amount doping of Mg and F doesn＇t change the spinel structure of LiMn204. Moreover, the samples of LiMn2O4 and LiMn1.95 Mg0.05O3.9 F0.1 had an initial discharge capacity of 121.3mAh/g and 123.7 mAh/g at 0.2 C, and 82.1% and 91.4% of the original capacity were reserved after 60 cycles, respectively. The LiMn1.95 Mg0.05O3.9 F0.1 had a discharge capacity of 92.4 mAh/g at 5 C,higher than the 76.5mAh/g of LiMn2O4. It can conclude that Mg and F co do- ping could suppress the Jahn-Teller distortion, enhanced the electrochemical performance and improved the cycle stability and rate capability. K

关 键 词：锂离子电池 正极材料 LIMN2O4 掺杂 电化学性能 

分 类 号：TM912[电气工程—电力电子与电力传动]