Article ID Journal Published Year Pages File Type
1610668 Journal of Alloys and Compounds 2014 35 Pages PDF
Abstract
Spherical Ni0.6Co0.2Mn0.2(OH)2 precursor with the concentration of Ni and Mn changed in opposite was prepared by co-precipitation. Then, well-ordered spherical LiNi0.6Co0.2Mn0.2O2 was synthesized by sintering the mixture of as-prepared precursor and LiOH⋅H2O first calcined at 550 °C for 4 h in air, followed at 820 °C for 12 h in flowing oxygen. Their structural and electrochemical properties were investigated using X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), charge-discharge test, cyclic voltammetry (C-V) method and electrochemical impedance spectroscopy (EIS) test. The concentration-gradient material had a superior electrochemical performances compared to conventional homogeneous LiNi0.6Co0.2Mn0.2O2 material, demonstrated by the results of C-V and EIS. The results of charge and discharge test demonstrated that the concentration-gradient LiNi0.6Co0.2Mn0.2O2 cathode material sintered at 820 °C delivered an initial discharge capacity of 174.3 mA h g−1 at 1 C rate between 2.8 and 4.3 V and more than 93.1% of that was retained after 100 cycles. Besides, this material also exhibited excellent rate capability and high voltage cut-off and temperature performance.
Related Topics
Physical Sciences and Engineering Materials Science Metals and Alloys
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