Authors: Feng Wu Huaquan Lu Yuefeng Su Ning Li Liying Bao Shi Chen
Publish Date: 2009/12/24
Volume: 40, Issue: 4, Pages: 783-789
Abstract
The Lirich layered cathode material LiNi02Li02Mn06O2 was synthesized via a “mixed oxalate” method and its structural and electrochemical properties were compared with the same material synthesized by the sol–gel method Xray diffraction XRD shows that the synthesized powders have a layered O3–LiCoO2type structure with the R3m symmetry Xray photoelectron spectroscopy XPS indicates that in the above material Ni and Mn exist in the oxidation states of +2 and +4 respectively The layered material exhibits an excellent electrochemical performance Its discharge capacity increases gradually from the initial value of 228 mA hg−1 to a stable capacity of over 260 mA hg−1 after the 10th cycle It delivers a larger capacity of 258 mA hg−1 at the 30th cycle The dQ/dV curves suggest that the increasing capacity results from the redoxreaction of Mn4+/Mn3+We acknowledge the financial supports from the National Basic Research Program 2009CB220100 and BIT Basic Research Fund No 20070542004 We also would like to thank Dr Guangyao Liu of Institute of Physics Chinese Academy of Sciences for his contribution to the Rietveld refinement of the XRD pattern
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