Effect of Sm₂O₃ modification on Li[Li_0.2Mn_0.56Ni_0.16Co_0.08]O₂ cathode material for lithium ion batteries

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• 作者：S.J. Shi ; J.P. Tu ; Y.J. Zhang ; Y.D. Zhang ; X.Y. Zhao ; X.L. Wang ; C.D. Gu
• 关键词：Lithium-rich manganese nickel cobalt oxide ; Samarium oxide ; Surface modification ; Cyclic stability ; Lithium ion battery
• 刊名：Electrochimica Acta
• 出版年：2013
• 出版时间：1 October, 2013
• 年：2013
• 卷：108
• 期：Complete
• 页码：441-448
• 全文大小：2204 K

文摘

Sm₂O₃-modified Li[Li_0.2Mn_0.56Ni_0.16Co_0.08]O₂ was synthesized via a simple wet chemical process followed by a solid state reaction. A thin Sm₂O₃ layer with a thickness of about 2.5 nm was uniformly coated on the surface of the Li-rich layered oxide particles. After Sm₂O₃ surface modification, high discharge capacity of 214.6 mAh g^?1 with a retention of 91.5 % is obtained at a current density of 200 mA g^?1 between 2.0 V and 4.8 V after 80 cycles. Electrochemical impedance spectroscopy (EIS) shows that the thin Sm₂O₃ layer mainly reduces the charge transfer resistance and stabilizes the surface structure of the active material during cycling. Sm₂O₃ modification will be a promising approach to improve the cyclic stability of Li-rich layered oxides.