Improved solid-state synthesis and electrochemical properties of LiNi0.6Mn0.2Co0.2O2 cathode materials for lithium-ion batteries

LiNi 0.6 Mn 0.2 Co 0.2 O 2 is considered as a promising Ni-rich layered cathode material of lithium-ion batteries due to low cost and high capacity. However, it is generally prepared by complicated precursor methods. In this work, LiNi 0.6 Mn 0.2 Co 0.2 O 2 is synthesized by a solid-state method with manganese acetate as manganese source and an effective mixing way. The as-prepared samples are characterized by XRD, FESEM, XPS and electrochemical techniques. The results show that the synthesized LiNi 0.6 Mn 0.2 Co 0.2 O 2 cathode materials have an α-NaFeO 2 type structure with insignificant cation mixing, octahedral single crystal and quasi sphere morphology, smaller particle size and good dispersion, so that it displays an initial discharge capacity of 163.6 mAh g −1 with a coulombic efficiency of 85.6% at 0.1C, a capacity retention of 99.1% after 100 cycles at 0.5C and an excellent rate performance, and also an initial discharge capacity of 177.3 mAh g −1 with capacity retention of 94.6% after 155 cycles at 55 °C. • Octahedral single crystal and quasi sphere of LiNi 0.6 Mn 0.2 Co 0.2 O 2 is synthesized by solid-state reaction. • LiNi 0.6 Mn 0.2 Co 0.2 O 2 has high crystallinity layered structure and insignificant cation mixing. • LiNi 0.6 Mn 0.2 Co 0.2 O 2 shows excellent coulombic efficiency, cycle stability and rate performance.