Controllable Constructionof CeO₂ Shellswith a Nanoscale Thickness to Enhance the High-Voltage ElectrochemicalPerformance of Ni-Rich Cathodes

Surface coating with metal oxide shells has been widely adopted across various fields due to the exceptional advantages these materials offer. However, achieving the controllable construction of uniform metal oxide shells with nanoscale thickness through a simple and cost-effective method remains challenging, primarily due to the high activity of metal ions. In this work, we proposed a cooperative regulation strategy that was successfully applied to construct uniform CeO₂ shells. Anhydrous ethanol was used as the solvent to reduce the reactivity of Ce(III) ions, while hexamethylenetetramine acted as a precipitant, precisely controlling the precipitation kinetics through its unique slow-release effect. This strategy resulted in high uniformity of the CeO₂ shells and enabled precise regulation of their thickness at the nanoscale, along with control over their crystalline state. The method was successfully applied to coat the LiNi_0.83Co_0.11Mn_0.06O₂ (N83) cathode. By leveraging the advantages of CeO₂ in chemical/thermal stability, oxygen storage capability, and electronic/ionic conductivity, the CeO₂ shell effectively protected the cathode and mitigated lattice oxygen release. As a result, the cycling performance, high-temperature stability, and rate capability of N83 exhibited significant improvements. This work presents a viable approach for the fabrication of controllable metal oxide shells with a nanoscale thickness.