Al, Zr dual-doped cobalt-free nickel-rich cathode materials for lithium-ion batteries

Abstract

Nickel-rich and cobalt-free cathode materials have obvious advantages in the aspects of energy density and economic efficiency. However, these materials are restricted from being used in commercial lithium-ion batteries due to the problems of poor structural stability and rate capability. In this study, the aluminum and zirconium dual-doped Co-free Ni-rich LiNi0.96Mn0.04O2 cathode material (NMAZ) is prepared by a facile high-temperature solid-phase method. The obtained NMAZ shows low cation disordering degree owing to the stability of transition metal slabs induced by strong Al–O and Zr–O bonds. Besides, the kinetics of lithium-ion diffusion is significantly improved by larger c-axis and the fast lithium-ion conducting Li2ZrO3 layer on the interface. As a result, NMAZ shows an improved capacity retention of 70.3% at 1C after 100 cycles under an elevated temperature (45 ​°C), compared with 50.5% of pure LiNi0.96Mn0.04O2. In addition, it exhibits splendid rate performance even at higher C-rate and better thermal stability compared to bare LiNi0.96Mn0.04O2. Hence, the Al, Zr dual-doped modification is beneficial to improving the structural stability and electrochemical performance of the Ni-rich and Co-free layered oxide cathodes for Li-ion batteries.