Lithium-rich cathode material doped with rare earth elements for application in lithium-ion battery

The influence of doping was investigated on the properties of layered Li1.2Mn0.54Ni0.13Co0.13O2 with a α-NaFeO2 prepared using LiCH3COO.2H2O, Mn(CH3COO)2.4H2O, Ni(CH3COO)2.4H2O and Co(CH3COO)2.4H2O via hydrothermal reaction. X-ray diffraction (XRD), Transmission electron microscopy (TEM), charge-discharge and electrochemical impedance spectroscopy (EIS) tests were applied to investigate structure, morphology and electrochemical performance of the lithium-rich doped sample. XRD analysis confirms that the uniform solid solution has been formed in the as-prepared compound without any impurities. It is shown that the crystal lattice parameters (a, c) of the doped compound is bigger than pristine compound. TEM image of the compound shows that cubic-like microparticles with a mean grain size of 600 nm have been formed. Galvanostatic charge-discharge test exhibits that doped sample has a discharge capacity of 257 mAh.g-1 in the voltage range of 2-4.8V. EIS results demonstrate that doping decreases charge transfer resistance and enhances conductivity and reaction kinetics due to high current ions and electrons of the doped element.

کلیدواژه ها:

Lithium-ion battery ، Layered lithium-rich cathode material ، Doping ، Rare earth element ، Hydrothermal method