Ultrafast, in situ transformation of a protective layer on lithium-rich manganese-based layered oxides for high-performance Li-ion batteries

Abstract

Li-rich Mn-based layered oxides provide a compelling amalgamation of high theoretical capacity and cost-effectiveness, positioning them as prime contenders for next-generation lithium-ion battery cathodes. However, their vulnerability to surface instability gives rise to a host of challenges, notably severe capacity and voltage fading. Consequently, the surface modification of Li-rich Mn-based layered oxides emerges as a viable solution to tackle this issue. Nevertheless, current methods exhibit various drawbacks, encompassing time-intensive procedures, environmental unfriendliness, and challenges in scalability. Hence, we present a technique employing ultrafast high-temperature heating technology to dynamically reshape the chemistry and structure of the surface of individual single-crystal Li_1.2Mn_0.54Ni_0.13Co_0.13O₂ cathode particles (LMLO) within a rapid 8-second timeframe. Structural analysis reveals the seamless integration of the spinel structure onto the surface, intricately linked to the internal layered structure, accompanied by a notable abundance of oxygen vacancies. Leveraging the distinctive features of this modified structure, the material demonstrates enhanced discharge capacity, superior rate performance, and prolonged cycling stability compared to the unmodified counterpart. Significantly, in stark contrast to alternative preparation methods, this technique accomplishes the formation of the protective layer within a mere 8 seconds, showcasing unparalleled efficiency. Furthermore, it boasts safety and environmental friendliness, necessitates basic instrumentation, boasts ease of operation, and is well-suited for large-scale adoption. Consequently, this method is positioned to drive the commercialization of Li-rich Mn-based layered oxide cathode materials.