采用微波辅助液相燃烧法制备了一系列LiMoxMn2-xO4(x=0,0.01,0.03,0.05)正极材料,通过XRD、SEM、CV等表征分析了材料的晶体结构、微观形貌和电化学性能。XRD和SEM数据表明,掺杂钼不会改变尖晶石型锰酸锂的结构,但能够提高材料的结晶性,掺杂钼后的样品颗粒分散均匀,形状更为规整。电化学性能测试结果表明,x=0.01时,样品的性能最佳,在室温、1C的放电条件下,LiMo0.01Mn1.99O4的首次放电比容量可达116.9mAh/g,高于纯锰酸锂的首次放电比容量(108mAh/g)。由此可见,适量钼的掺杂能够改善锰酸锂材料的结晶性,并提高材料的首次放电比容量。
A series of LiMoxMn2-xO4(x=0,0.01,0.03,0.05) cathode materials were successfully prepared by microwave-assisted liquid phase combustion method.The crystal structure,microstructure and electrochemical performance of the materials were analyzed by XRD,SEM and CV.The XRD and SEM data shown that doping molybdenum did not change the structure of spinel LiMn2O4,and it can improve the crystallinity of the material.The Mo-doped sample particles were uniformly dispersed and the shape was more regular.The electrochemical performance test results shown that the sample was best when x=0.01.At room temperature and 1C discharge,the first discharge specific capacity of LiMo0.01Mn1.99O4 can reach 116.9mAh/g,which was higher than pure LiMn2O4 of was only 108mAh/g.Therefore,the Mo doping with appropriate amount can improve the crystallinity of the LiMn2O4 material,and provided the first discharge specific capacity of the material.
[1] 毛丽萍,杜松丽,崔孝玲,等.纳米LiMn2O4的研究进展[J].化工新型材料,2016,44(9):50-52.
[2] 丁方.锂离子电池三元正极材料的制备、包覆和电化学性能的研究[D].贵阳:贵州师范大学,2014.
[3] 方俊杰,李莹,宋永慧,等.Al和Si等量共掺杂对LiMn2O4材料的电化学性能影响[J].电源技术,2018,42(10):1441-1443.
[4] Li X,Xu Y,Wang C.Suppression of Jahn-Teller distortion of spinel LiMn2O4 cathode[J].Journal of Alloys and Compounds,2009,479(1-2):0-313.
[5] Kumar R,Funeka P,Elumalai V,et al.Microwave-enhanced electrochemical cycling performance of the LiNi0.2Mn1.8O4 spinel cathode material at elevated temperature[J].Physical Chemistry ＆Chemical Physics,2016,18,13074-13083.
[6] Zhao H,Liu S,Wang Z,et al.Enhanced elevated-temperature performance of LiAlxSi0.05Mg0.05Mn1.90-xO4(0≤x≤0.08) cathode materials for high-performance lithium-ion batteries[J].Electrochimica Acta,2016,199:18-26.
[7] Gummow R,Kock A D,Thackeray M M.Improved capacity retention in rechargeable 4V lithium/lithium-manganese oxide (spinel) cells[J].Solid State Ionics,Diffusion & Reactions,1994,69(1):59-67.
[8] 刘红雷,于月,白玮,等.Co掺杂尖晶石型LiMn2O4正极材料研究进展[J].云南化工,2018,45(12):6-10.
[9] 郭光辉,陈珊,刘芳芳,等.尖晶石型LiMn2O4掺杂研究进展[J].化工新型材料,2013,41(10):169-171.
[10] Thirunakaran R,Ravikumar R,Vijayarani S,et al.Molybdenum doped spinel as cathode material for lithium rechargeable cells[J].Energy Conversion and Management,2012,53(1):276-281.
[11] 贾海涛,张宏坤,李文娟,等.Mo掺杂LiMn2O4的制备及其电化学性能研究[J].电池工业,2011,16(3):168-171.
[12] Jayapal,Suganya,Mariappan,et al.Dopant depends on morphological and electrochemical characteristics of LiMn2-xMoxO4 cathode nanoparticles[J].Journal of Solid State Electrochemistry,2013,17(8):2157-2165.
[13] Chen M,Chen P,Yang F,et al.Ni,Mo Co-doped lithium manganate with significantly enhanced discharge capacity and cycling stability[J].Electrochimica Acta,2016,206:356-365.
[14] Deng Y,Wang S,Zhou Y,et al.The enhancement of rate and cycle performance of LiMn2O4 at elevated temperatures by the synergistic roles of porous structure and dual-cationdoping[J].Journal of Applied Electrochemistry,2018,48(10):1083-1094.
[15] Fu Y P,Lin C H,Su Y H,et al.Electrochemical properties of LiMn2O4 synthesized by the microwave-induced combustion method[J].Ceramics International,2004,30(7):1953-1959.
[16] Liu H Y,Deng G Q,Guo Y L.Influence of Sc3+ on LiMn2O4 cathode materials at elevated temperature[J].Journal of Rare Earths,2008,26(5):722-726.
[17] Zhang H,Liu D,Zhang X,et al.Microwave synthesis of LiMg0.05Mn1.95O4 and electrochemical performance at elevated temperature for lithium-ion batteries[J].Journal of Solid State Electrochemistry,2014,18(2):569-575.
[18] 杨书廷,贾俊华,郑立庆,等.稀土掺杂对锂离子电池正极材料LiMn2O4结构及电性能的影响[J].中国稀土学报,2003(4):413-416.
