Electrochemically Inert Li2MnO3: The Key to Improving the Cycling Stability of Li-Rich Manganese Oxide Used in Lithium-Ion Batteries

Lithium-rich manganese oxide is a promising candidate for the next-generation cathode material of lithium-ion batteries because of its low cost and high specific capacity. Herein, a series of xLi(2)MnO(3)center dot(1 - x)LiMnO2 nanocomposites were designed via an ingenious one-step dynamic hydrothermal route. A high concentration of alkaline solution, intense hydrothermal conditions, and stirring were used to obtain nanoparticles with a large surface area and uniform dispersity. The experimental results demonstrate that 0.072Li(2)MnO(3)center dot 0.928LiMnO(2) nanoparticles exhibit a desirable electrochemical performance and deliver a high capacity of 196.4 mAh g(-1) at 0.1 C. This capacity was maintained at 190.5 mAh g(-1) with a retention rate of 97.0% by the 50th cycle, which demonstrates the excellent cycling stability. Furthermore, XRD characterization of the cycled electrode indicates that the Li2MnO3 phase of the composite is inert, even under a high potential (4.8 V), which is in contrast with most previous reports of lithium-rich materials. The inertness of Li2MnO3 is attributed to its high crystallinity and few structural defects, which make it difficult to activate. Hence, the final products demonstrate a favorable electrochemical performance with appropriate proportions of two phases in the composite, as high contents of inert Li2MnO3 lower the capacity, while a sufficient structural stability cannot be achieved with low contents. The findings indicate that controlling the composition through a dynamic hydrothermal route is an effective strategy for developing a Mn-based cathode material for lithium-ion batteries.

Automated summary

Lithium-rich manganese oxide nanocomposites with high electrochemical performance and cycling stability were successfully designed through a dynamic hydrothermal route, utilizing intense hydrothermal conditions and stirring to produce nanoparticles with large surface area and uniform dispersity. The incorporation of Li2MnO3 phase in appropriate proportions was found to be crucial in maintaining high capacity and structural stability in the composite material.