Organic carbon gel assisted-synthesis of Li1.2Mn0.6Ni0.2O2 for a high-performance cathode material for Li-ion batteries

Lithium-rich layered oxide Li1.2Ni0.2Mn0.6O2 with a stable network flake structure has been synthesized through a facile resorcinol–formaldehyde (RF) organic carbon gel-assisted method. The as-prepared sample used as a cathode material in lithium ion batteries (LIBs) was characterized by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and electrochemical measurements. The stable network flake structure is assembled through a dense stack of nanoparticles with an average size of 50– 200 nm. As an active material for LIB cathodes, the Li1.2Ni0.2Mn0.6O2 sample shows excellent rate capacities and cycling stability, and delivers a high initial discharge capacity of 273.3 mA h g 1 at 0.1C (1C 1⁄4 200 mA g ) between 2.0 V and 4.8 V. When the discharge rate is increased to 2C, an initial capacity of 196.7 mA h g 1 is obtained. After 150 cycles, a discharge capacity of 183.7 mA h g 1 and a high capacity retention of 93.4% are yielded at a rate of 2C.