Open-Channel [011] Facet CeO<sub>2</sub> with a Shorter Pathway of Li<sup>+</sup> Migration as a Modification Material for LiNi<sub>0.8</sub>Co<sub>0.1</sub>Mn<sub>0.1</sub>O<sub>2</sub> toward High-Rate Lithium-Ion Batteries
Yu Ma, Fei Lv, Zhiqiang Wang, Jing Feng, Mengtao Wu, Zhifang Liu, Li Chen, Yuzong Gu
Abstract
A stable interface is vital for the long cycling stability of nickel-rich material LiNi0.8Co0.1Mn0.1O2 (NCM811). As such, the common remedy to improve the stability of nickel-rich layered oxide is to adopt a coating strategy. However, most of the coating materials used in this strategy are often randomly oriented, which may pose challenges toward efficient Li+ transportation from the electrolyte to the core material and vice versa. In this work, we demonstrate with the use of a CeO2 shell with [011] exposed facets as a well-oriented coating material with a shorter straight Li+ migration pathway and higher electronic conductivity to further improve the stability and rate performance of the nickel-rich layered oxide. As a result, our CeO2[011]-modified LiNi0.8Co0.1Mn0.1O2 (1.0%-NCM811) showed improved electrochemical performance, especially in terms of rate capability. Cycling stability was also enhanced for tests conducted at room temperature and at an elevated temperature of 55 °C. The higher rate performance by our 1.0%-NCM811 may stem from the open shorter channels available in the [011] facet and the higher electrical conductivity. Based on this work, the orientation of the coating material is crucial as it could affect the rate capability of the core material drastically.