Performance improvement of Li-rich layer-structured Li1.2Mn0.54Ni0.13Co0.13O2 by integration with spinel LiNi0.5Mn1.5O4

Abstract

Li-rich layered Li_1+xMn_yM_1−x−yO₂ (or denoted xLi₂MnO₃·(1 − x)LiMO₂, M = Ni, Co, Mn, etc.) are promising cathode materials for high energy-density Li-ion batteries. However, their commercial applications suffer from problems such as a drop in the capacity and discharge voltage during cycling. In this work, the cycling performance of a layered oxide Li_1.2Ni_0.13Co_0.13Mn_0.54O₂ is improved by integration with spinel LiNi_0.5Mn_1.5O₄ to obtain a layered–spinel composite. Characterization by powder X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM) as well as cyclic voltammetry (CV) indicates that delayed degradation of layered Li₂MnO₃ and the suppressed growth of LiMn₂O₄-like spinel are responsible for the performance improvement.