Effect of Sm2O3 modification on Li[Li0.2Mn0.56Ni0.16Co0.08]O2 cathode material for lithium ion batteries

• Published in: Electrochimica acta 2013-10, Vol.108, p.441-448
• Main Authors: Shi, S.J., Tu, J.P., Zhang, Y.J., Zhang, Y.D., Zhao, X.Y., Wang, X.L., Gu, C.D.
• Format: Article
• Language: English
• Subjects: Charge transfer; Cycles; Cyclic stability; Discharge; Electrochemical impedance spectroscopy; Lithium batteries; Lithium ion battery; Lithium-ion batteries; Lithium-rich manganese nickel cobalt oxide; Oxides; Samarium oxide; Stability; Surface modification; Thin films
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2013.07.020

•Sm2O3 is well coated on Li[Li0.2Mn0.56Ni0.16Co0.08]O2 by simple wet chemical method.•The coated sample exhibits high capacity of 234.5mAhg−1 at 1C.•Capacity retention of 91.5% is obtained at 1C (200mAg−1) after 80 cycles 25°C.•EIS shows the thin Sm2O3 layer mainly reduces the charge transfer resistance. Sm2O3-modified Li[Li0.2Mn0.56Ni0.16Co0.08]O2 was synthesized via a simple wet chemical process followed by a solid state reaction. A thin Sm2O3 layer with a thickness of about 2.5nm was uniformly coated on the surface of the Li-rich layered oxide particles. After Sm2O3 surface modification, high discharge capacity of 214.6mAhg−1 with a retention of 91.5% is obtained at a current density of 200mAg−1 between 2.0V and 4.8V 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.