湿化学法合成LiNi 1/3 Mn 1/3 Co 1/3 O 2 及其表征

A series of cathode materials LiNi1/3Mn1/3Co1/3O2 for lithium-ion batteries were successfully synthesized using succinic acid as a chelating agent by a wet-chemical method. We varied the succinic acid to metal. ion molar ratios (R) and investigated the effect of this parameter on the physical and electrochemical properties of the prepared LiNi1/3Mn1/3Co1/3O2. The reaction mechanism, structural, morphological, and magnetic properties of the powders were characterized in detail by thermogravimetry (TG), X-ray diffraction (XRD), Rietveld refinement, scanning electron microscopy (SEM), and superconducting quantuminterface device (SQUID). We determine that the optimumconditions for the synthesis of LiNi1/3Mn1/3Co1/3O2 assisted with succinic acid is R= 1, at the lowest amount of cation mixing. In addition, measurement of the magnetic properties revealed a concentration of Ni on the 3b Wyckoff site of the lithium. ions in good agreement with the results from the Rietveld refinement on the XRD spectra. For LiNi1/3Mn1/ 3Co1/3O2 (R=1), the Rietveld refinement showed that cation mixing in this sample was 1.85%, which is in quantitative agreement with that fromthe SQUIDresult (1.80%). It delivered an initial discharge capacity of 161 mAh.g(-1) at a current rate of 0.2C (1C= 160 mA.g(-1)) and at a cut-off voltage of 3.0-4.3 V with a coulombic efficiency of 93.1% and its capacity retention was 91.3% after 50 cycles.