The structural and electrochemical performance of Mg-doped LiNi0.85Co0.10Al0.05O2 prepared by a solid state method

Abstract Mg-doped LiNi0.85Co0.10Al0.05O2 (NCA) is first synthesized through a solid state reaction using available precursors via a nano-scal sand milling method. Compared with other methods of preparing the nickel-rich precursors, the novel way of obtaining nickel-rich precursors is simple and environmental-friendly. X-Ray Diffraction (XRD) results show that Mg-doped NCA displays a typical layered hexagonal structure with no impurity phase or an enlarged c-axis and d(003) as defined by the Rietveld refinement method. Scanning Electron Microscope (SEM) and X-Ray Photoelectron spectroscopy (XPS) results demonstrate the intact particle morphology and increased the percentage of Ni2+ on the surface of Mg-doped NCA materials, respectively. The cyclic voltammetry results exhibit a slight decrease in the polarization of NCA electrodes after Mg doping. Moreover, Mg-doped NCA possesses higher cycling retention at 25 °C and 55 °C than the pure NCA. Meanwhile, Electrical Impedance Spectroscopy (EIS) and Galvanostatic Intermittent Titration Technique (GITT) tests confirm that Mg-doped NCA shows lower total impedance values after 100 cycles, as well as demonstrate a higher lithium-ion diffusion coefficient of Mg-doped NCA (8.196 × 10−13 cm2·s−1) when compared to NCA (3.743 × 10−13 cm2·s−1) at 3.74 V during discharge process.