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

Abstract

Lithium-rich layered oxide Li_1.2Ni_0.2Mn_0.6O₂ 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 Li_1.2Ni_0.2Mn_0.6O₂ 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 = 200 mA g⁻¹) 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.