A simple strategy to prepare the La2Li0.5Al0.5O4 modified high-performance ni-rich cathode material

LiNi0.8Co0.1Mn0.1O2(NCM811) is regarded as one of the promising Li-ion battery cathode materials due to the high capacity and low cost, but the poor cyclic and rate performances hinder its widespread application. In our research, La and Al co-modified NCM811 is successfully prepared by a simple method. XRD and XPS confirm that La and Al can not only dope into the NCM811 bulk, but also form the La2Li0.5Al0.5O4 coating layer on the surface. The La2Li0.5Al0.5O4 coated and La-and-Al-doped NCM811 exhibits an excellent capacity retention of 97.2% at 1C in the voltage range of 3.0–4.4 V after 100 cycles, 18.5% higher than that of the pristine. As for rate performance, it exhibits a retention of 95.1% in capacity at 5C after 80 cycles from 3.0 V to 4.4 V, 6.4% higher than that of the pristine. The enhanced high-voltage electrochemical performances are mainly ascribed to the facts that the La and Al strengthen the bulk structure by co-doping and the formed La2Li0.5Al0.5O4 coating layer, as the high-Tc superconducting oxides, not only promotes the diffusion of Li+ but also protect the cathodes from eroding by with the electrolyte. Meanwhile, the residual lithium is reduced by the formation of La2Li0.5Al0.5O4. The enhanced electrochemical performance shows that the modification of La2Li0.5Al0.5O4 coating and La–Al co-doping is a competitive method for industrial production of NCM811 material. •The La–Al co-doping and La2Li0.5Al0.5O4 coating NCM811 cathode material was prepared by a simple method.•The La and Al were doped in the host material uniformly.•La2Li0.5Al0.5O4 coating protects the active material from electrolyte eroding.•The co-modification method contributes to the superior electrochemical performances of NCM811.