Acta Scientiarum Naturalium Universitatis Pekinensis

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Synthesis of High Tap-Density Layered LiMn0.4Ni0.4Co0.2O2 Cathode Material

DAI Kehua1), WANG Yinjie2), HE Ping1), XIE Yanting1), Qilu1, 3)
(1)New Energy Material and Technology Laboratory, Department of Applied Chemistry, College of Chemistry and Molecular Engi   

  • Received:2006-09-18 Online:2006-12-30 Published:2006-12-30

高密度LiMn0.4Ni0.4Co0.2O2正极材料的合成与研究

代克化1), 王银杰2), 何平1), 谢燕婷1), 其鲁1, 3)
(1)北京大学化学与分子工程学院, 应用化学系, 新能源材料与技术实验室, 北京, 100871; 2)北京理工大学材料科学与工程学院, 北京, 100081; 3)通讯作者, E-mail: qilu@pku.edu.cn)   

Abstract: Uniform spherical metal hydroxide Mn0.4Ni0.4Co0.2(OH)2 was prepared via improved hydroxide precipitation, and then LiMn0.4Ni0.4Co0.2O2 was prepared by mixing this metal hydroxide with 5% excess LiOH by heat-treatment. It is shown that the product with the high tap-density of 2.3g·cm-3 can be prepared under relatively extensive condition via the addition of F- in system. The product was characterized using X-ray diffraction(XRD), scanning electron microscope (SEM) and charge-discharge tests. The SEM results show that the product has a good morphology, and the XRD studies demonstrate that the material has a well-ordered layered structure without impurity phase. The initial charge and discharge capacities are 185 and 164mAh·g-1 at a voltage range from 3.0 to 4.0V and a current density of 30mA·g-1, and 90% of the discharge capacity is retained after 50 charge-discharge cycles.

Key words: Li-ion battery, cathode material, co-precipitation

摘要: 用一种改进的氢氧化物共沉淀法制备了粒径均一、近球形的Mn0.4Ni0.4Co0.2(OH)2, 再通过高温固相合成法制备了高密度的LiMn0.4Ni0.4Co0.2O2正极材料。结果表明,在沉 淀体系中加入F-,可以在较为宽松的条件下制备出振实密度为2.3g·cm-3的LiMn0.4Ni0.4Co0.2O2正极材料。对产物进行了XRD、SEM和充放电测试。SEM测试结果表明,产物具有良好的形貌; XRD测试表明,产物具有良好的层状结构,无杂质相存在。在充放电电压区间为3.0~4.4V,电流密度为30mA·g-1时,首次充电和放电容量分别为185和164mAh·g-1,经过50次循环,放电容量仍能保持90%。

关键词: 锂离子电池, 正极材料, 共沉淀

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