Insights into Li-Rich Mn-Based Cathode Materials with High Capacity: from Dimension to Lattice to Atom

摘要

Li-rich Mn-based layered oxides are regarded as the most promising cathode materials for advanced lithium-ion batteries with energy density as high as 400 Wh kg(-1). However, decline of capacity and discharge potential derived from phase transformation during cycling is still an obstacle for practical utilization of Li-rich cathode materials. Undoubtedly, an in-depth understanding origin and evolution of the phase transformation from bottom to top is crucial to solve the problem finally. Herein, the recent representative progress on Li-rich cathode materials from top to bottom is summarized: starting from relationship between dimensions and performance, to evolution of phase transformation, finally to participation of anions during charge-discharge cycling. It systematically shows what happens in the different microscopic levels and how these phenomena relate to cycling of Li-rich cathode materials with the help of emerging state-of-the-art characterization techniques. On the basis of this progress, it is proposed that rational structural design can fully play its role to build high-performance energy storage materials and enhance structural stability.