Synthesis, characterization and electrochemical performance of Li[Li_(0.2)Mn_(0.54)Ni_(0.13)Co_(0.13)]O_2 cathode materials for lithium-ion batteries

摘要

The layered Li-rich Li[Li_(0.2)Mn_(0.54)Ni_(0.13)Co_(0.13)]O_2 cathode material is successfully synthesized via an optimized sol-gel method. With oxalic acid instead of citric acid as the chelating agent, the amount of chelating agent used in this experiment is only 36% of the traditional weight. Segmented sintering method is adopted to decrease the calcination temperature and reduce the calcination time. X-ray diffraction spectrometry (XRD) and scanning electron microscopy (SEM) are used to characterize the structure and micromorphology of the material. Meanwhile, charge-discharge test, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) are employed to explore its electrochemical performance. Our results demonstrate that Li[Li_(0.2)Mn_(0.54)Ni_(0.13)Co_(0.13)]O_2 electrode delivers a high reversible capacity of 277.3 mAh g~(-1) and keeps excellent capacity retention of 98.4% after 50 cycles when tested at a 0.1 C rate within the potential range of 2.0-4.8 V at room temperature.