掺杂Eu对LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2结构及电化学性能的影响
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摘要
采用草酸盐共沉淀法合成了掺杂Eu的锂离子电池正极材料LiNi_(1/3)Co_(1/3-x)Mn_(1/3)Eu_xO_2(x=0、0.2%、0.4%、0.6%和0.8%)。采用X射线衍射(XRD)和扫描电镜(SEM)对材料的结构和形貌进行了表征。通过LAND CT2001A电池测试系统对所制得样品进行电化学性能测试。结果表明:掺杂Eu后的样品都具有典型的a-NaFeO_2的特征层状结构,且晶型良好。掺杂量x=0.4%的样品粒径均匀,约为0.4～1 mm,团聚现象较少。充放电测试证实该样品在0.7 C下首次放电比容量为116.3 mAh/g,50次循环后放电比容量为114.1 mAh/g,容量保持率为98.12%,高于未掺杂样品的88.36%。
Li-ion battery cathode material LiNi_(1/3) Co_(1/3-x)Mn_(1/3) Eu_xO_2(x=0、0.2%,0.4%,0.6% and 0.8%) was synthesized by oxalate co-precipitation method. The structure, morphology and electrochemical properties of the material were characterized by x-ray diffraction(XRD), scanning electron microscope(SEM) and LAND CT2001 A cell test system.The result show that the samples after Eu-doping have the typical structure of layered a-NaFeO_2 type and crystal structure is perfect. The doping amount x=0.4% of the sample particle size is uniform, about 0.4～1 mm, agglomeration phenomenon is less. Charge-discharge test clarified that the sample in which x=0.4% had a initial discharge capacity of 116.3 mAh/g at 0.7 C, and the discharge capacity was 114.1 mAh/g after 50 th cycle, 98.12% of capacity was retained, which is higher than 88.36% of the undoped sample.
Li-ion battery cathode material LiNi_(1/3) Co_(1/3-x)Mn_(1/3) Eu_xO_2(x=0、0.2%,0.4%,0.6% and 0.8%) was synthesized by oxalate co-precipitation method. The structure, morphology and electrochemical properties of the material were characterized by x-ray diffraction(XRD), scanning electron microscope(SEM) and LAND CT2001 A cell test system.The result show that the samples after Eu-doping have the typical structure of layered a-NaFeO_2 type and crystal structure is perfect. The doping amount x=0.4% of the sample particle size is uniform, about 0.4～1 mm, agglomeration phenomenon is less. Charge-discharge test clarified that the sample in which x=0.4% had a initial discharge capacity of 116.3 mAh/g at 0.7 C, and the discharge capacity was 114.1 mAh/g after 50 th cycle, 98.12% of capacity was retained, which is higher than 88.36% of the undoped sample.
引文
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[2] ZHONG S K, WANG Y, LIU J Q, et al. Synthesis and electrochemical properties of Ce-doped LiNi1/3Mn1/3Co1/3O2cathode material for Li-ion batteries[J].稀土学报(英文版), 2011, 29(9):891-895.
[3] LI Y, ZHONG S. Synthesis and electrochemical properties of Y-doped LiNi1/3Mn1/3Co1/3O2cathode materials for Li-ion battery[J].Integrated Ferroelectrics, 2011, 127(1):150-156.
[4]胡传跃,郭军,汪形艳,等.草酸盐共沉淀法制备层状LiNi1/3-Co1/3-xLaxMn1/3O2正极材料[J].电源技术, 2010,34(12):1230-1232.
[5] WENG Y Q, XU S M. Synthesis and performance of Li[(Ni1/3Co1/3-Mn1/3)1-xMgx]O2prepared from spent lithium ion batteries[J]. Journal of Hazardous Materials, 2013, 246:163-172.
[6] YABUUCHI N, OHZUKU T. Novel lithium insertion material of LiCo1/3Ni1/3Mn1/3O2, for advanced lithium-ion batteries[J]. Journal of Power Sources, 2003, s119/121(6):171-174.
[7]刘建本,莫如宝,吴显明.锂离子正极材料Li(Nil/3Col/3Mnl/3)l-xAlxO2的制备及电化学性能[J].应用化学,2014,31(4):462-468.
[8]彭忠东,胡国荣,肖劲,等.掺杂稀土Eu对LiMn2O4结构和性能的影响[J].电源技术,2004(5):264-267.
[9] WU J F, LIU H G, YE X H, et al. Effect of Nb doping on electrochemical properties of LiNi1/3Co1/3Mn1/3O2at high cutoff voltage for lithium-ion battery[J]. Journal of Alloys and Compounds, 2015,644:223-227.
[10]李春霞.LiNi1/3Co1/3Mn1/3O2的制备和掺杂改性研究[D].长沙:中南大学,2007.
[11]梁荣荣.储锂材料LiNi1/3Co1/3Mn1/3O2和TiO2的制备及性能研究[D].武汉:武汉理工大学,2012.