Preparation of layered Ni-rich LiNi0.9Co0.05Mn0.05O2 cathode materials with excellent electrochemical properties by controllable lithium supply and sintering

Abstract

Layered Ni-rich cathode materials (LiNixCoyMn1-x-yO2) are promising cathode materials for next-generation lithium-ion batteries due to their high reversible capacity and energy density. However, it is still facing the challenges in unstable structure and weak electrochemical properties, inhibiting their large-scale application. Herein, Ni-rich LiNi0.9Co0.05Mn0.05O2 cathode materials are synthesized using Ni0.9Co0.05Mn0.05(OH)2 precursors and Li source by two-steps heating treatment processes. Their structure and properties are regulated by controlling Li supply amounts and sintering temperature to further expand the applications of Ni-rich cathode materials. Experimental results suggest that the preheating at 500 °C effectively establishes a structural foundation (R-3m) for the following sintering of LiNi0.9Co0.05Mn0.05O2 materials. Furthermore, it is found that Li supply amount and sintering temperature have a certain correlation with the structural stability and electrochemical properties of materials. At Li supply amount 1.04 (Li/transition metals atom ratio) and sintering temperature 700 °C, the prepared LiNi0.9Co0.05Mn0.05O2 materials exhibit optimal electrochemical properties (77.0 % capacity retention after 400 cycles at 1C, and about 128.0 mAh g‐1 discharge capacity at 10C). This study provides a rational regulating strategy for synthesizing Ni-rich LiNi0.9Co0.05Mn0.05O2 cathode materials with controllable structural and electrochemical properties, further expanding their applications in the fields of smart grids and electric vehicles.