Sacrificed template synthesis of Li_1.2Ni_0.13Co_0.13Mn_0.54O₂ spheres for lithium-ion battery cathodes

Porous and solid Li_1.2Ni_0.13Co_0.13Mn_0.54O₂ spheres have been prepared by spherical Ni_0.13Co_0.13Mn_0.54(CO₃)_0.8 and MnO₂-sacrificed templates route. X-ray diffraction profiles show two kinds of Li_1.2Ni_0.13Co_0.13Mn_0.54O₂ spheres have good layered structure with solid solution characteristic. Scanning electron microscope images reveal that the porous Li_1.2Ni_0.13Co_0.13Mn_0.54O₂ spheres obtained from spherical carbonate precursor are composed of well-defined primary nanoparticles. These nanoparticles have the size of 100–300 nm, and some porous structure can be observed among these particles on the surface. The solid spheres obtained from MnO₂ are made of tightly clustered nanoparticles. As lithium-ion battery cathodes, the porous spheres exhibit a high initial discharge capacity of 255.7 mAh g⁻¹ at 0.1 C between 2.0 and 4.8 V. After 50 cycles, a discharge capacity of 177.7 mAh g⁻¹ could be retained at 0.5 C. Even at high charge–discharge rate of 5 C (1,000 mA g⁻¹), 121.4 mAh g⁻¹ can be reached. But the solid spheres only deliver initial discharge capacity of 159.9 mAh g⁻¹ at 0.1 C. Anyway, the different electrochemical performances of two samples should be attributed to the use of different sacrificed templates.