Urea-assisted combustion synthesis of porous Li1.2Ni0.13Co0.13Mn0.54O2 microspheres as high-performance lithium-ion battery cathodes

An initial urea-assisted combustion and subsequent high-temperature crystallisation route have been used to prepare porous Li_1.2Ni_0.13Co_0.13Mn_0.54O₂ microspheres. The as obtained microspheres with the size of 2-4 μm are composed of numerous nanoparticles, and these nanoparticles with clear corner and edge have the size of 100-200 nm. A possible formation process of porous microspheres structures is discussed. As lithium-ion battery cathodes, the porous microspheres can deliver an initial discharge capacity of 252.3 mAh g^-1 with high Coulombic efficiency of 80.6% at current density of 20 mA g^-1, and keep a stable discharge capacity of 115.5 mAh g^-1 at 1000 mA g^-1. Although the sample obtained without urea only deliver a discharge capacity of 66.7 mAh g^-1 at 1000 mA g^-1. Maybe, the facile urea-assisted combustion route is suitable for the synthesis of lithium-rich layered oxides as lithium-ion battery cathodes.