Excellent rate performance and high capacity of Mo doped layered cathode material Li[Li0.2Mn0.54Ni0.13Co0.13]O2 derived from an improved coprecipitation approach

A Mo-doped layered cathode materials Li[Li0.2Mn0.54Ni0.13Co0.13]O2 (LMNC) with an excellent rate performance and high capacity have been successfully synthesized by a facile and novel organic co-precipitation process. The effect of trace Mo-doped on the surface morphology and crystal structures have been investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The results reveal that the Mo6+-doped electrode material with an optimal content could show a uniform particles size distribution and well-crystallization. Electrochemical measurements, including charge-discharge, cyclic voltammetry (CV) and electrochemical impedance spectra (EIS) have also been employed. It is demonstrated that the Mo-doped LMNC composites exhibit significant improvements on the electrochemical performance including the capacity, rate capability and cycle performance. For example, the initial discharge capacity is 260.8 mAh g−1 at 1 C for an optimal Mo-doped electrode, and still maintains an initial discharge capacity of 142.3 and 85.5 mAh g−1 at 10 and 20 C, and capacity retention could still be 83.56% and 96.14% after 100 cycles, respectively, indicating its excellent cycle and rate capability for LMNC materials. It is believed that the remarkably enhanced rate capability and cycling stability of these modified electrodes might be ascribed to trace Mo substitution prepared by this organic co-precipitation process.