Preparation and Electrochemical Characterization of La and Al Co-doped NCM811 Cathode Materials.

LiNi0.8Co0.1Mn0.1O2 (NCM811) became a research hot point because of its low cost, environmental friendliness, and excellent electrochemical performance. However, Li+/Ni2+ intermixing is an essential factor affecting its applicability. Doping could be an important method to improve the electrochemical performance of NCM811-based cathode materials. In this work, La and Al co-doped NCM811 was prepared by a solid-state method. Results from X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS) and electrochemical performance were discussed in depth. These showed that when La and Al doping concentrations were 1 and 0.5%, the samples showed the best performance. The as-improved performances were mainly attributed to the reduced Li+/Ni2+ intermixing, suppressed phase transition, and decreased potential polarization and impedance.