Influence of core and shell components on the Ni-rich layered oxides with core-shell and dual-shell structures

摘要

To understand the effect of core-shell structure on the electrochemical performance of Ni-rich layered oxides, LiNi0.6Co0.2Mn0.2O2 is redesigned to three core-shell structures on the foundation of LiNiO2-LiCoO2-LiMnO2 triangle phase diagram. After evaluated the electrochemical performances of the three core-shell structures, the optimized one, which used LiNi0.40Co0.2Mn0.4O2 as the shell component, were redesigned into dual-shell structure, which has the same outer shell with the core-shell structure to further investigate the influence of core component on the electrochemical performance of Ni-rich layered oxides. The core-shell structures are certified by the EDS results of a cross-section of particles. The electrochemical performances reveal that the dual-shell sample with LiNi0.8Co0.1Mn0.1O2 core exhibits the excellent electrochemical performances, which may be because LiNi0.8Co0.1Mn0.1O2 core can balance the capacity and structural stability in samples with dual-shell structure. This work reveal the relationship between the structure and electrochemical properties of Ni-rich layered oxides with core-shell structure, and provide a new clue to design high performance Ni-rich layered oxides for advanced Li-ion batteries.