Chemical-wet Synthesis and Electrochemistry of LiNi1/3Co1/3Mn1/3O2 Cathode Materials for Li-ion Batteries

LiNi1/3Co1/3Mn1/3O2 (LNCM) with a well-ordered layered structure, confirmed by X-ray diffraction, was synthesized by the chemical-wet synthesis incorporated with (i) a pulse microwave-assisted heating of LNCM precursors and (ii) a carbon coating technique. The microwave irradiation periods (i.e., 5-20 min) and amount of carbon additive (i.e., glucose content: 0.1-0.75%) served as key factors in modifying as-prepared LNCM powders. The electrochemical performance of as-prepared LNCM cathodes was well characterized by cyclic voltammetry and charge-discharge cycling at 0.1-5C. Both appropriate microwave heating and carbon coating significantly improve discharge capacity, rate capability, and cycling stability of LNCM cathodes. This improved performance can be attributed to the facts that an appropriate microwave heating of LNCM precursors induces low cation mixing of the layered lattices and the carbon coating enables the creation of outer circuit of charge-transfer pathway, preventing cathode corrosion from direct contact to the electrolyte. The C-coated LNCM cathode shows the increased capacity retention from 70.2 to 93.3% after 50 cycles at 1C. On the basis of the experimental results, both the microwave heating and the carbon coating provide a feasible potential way to improve the electrochemical performance of LNCM cathode, benefiting the development of Li-ion batteries.