Green and low-cost synthesis of LiNi_0.8Co_0.15Al_0.05O2 cathode material for Li-ion batteries

A spherical LiNi _0.8 Co _0.15 Al _0.05 O ₂ (NCA) cathode material is synthesized from the precursor Ni _0.8 Co _0.15 Al _0.05 (OH) ₂ obtained through a co-precipitation method using potassium sodium tartrate for the first time as a chelating agent. X-ray diffraction analysis proves that the as-prepared NCA is a hexagonal phase with perfectly ordered layered structure. Scanning electron microscope study shows that the morphology and size of NCA remain nearly the same as those of the precursor. Clear crystal lattice fringes arranged along the (0 0 3) plane can be found in transmission electron microscope images. The NCA material exhibits excellent electrochemical properties with initial charge/discharge capacities of 245.6/204.4, 201.2/196.3, 189.0/182.2 and 177.3/171.4 mAh·g ⁻¹ at 0.1, 0.2, 0.5 and 1.0 C, respectively, and charge/discharge capacity retentions of 91.9%/91.5% after 100cycles at 0.5 C in the voltage range of 2.8–4.3 V (vs. Li/Li ⁺ ).