Surface coating of cerium oxide nano layer for stable high energy Li-rich manganese-based cathode materials

A CeO 2 nano-coating layer on the LRM particles using a wet-chemical method. • Optimized cathode achieves a high initial discharge capacity of 226.17 mAh/g. • Maintains 75.0 % of its initial capacity after 500 cycles at a high rate of 1 C. • Dual function of CeO 2 : inhibiting interfacial reactions and oxygen buffer. Li-rich manganese-based cathode materials (LRM) are promising candidates for high-energy-density lithium-ion batteries. However, they face significant challenges such as capacity fade and voltage decay during cycling, primarily due to the release of surface lattice oxygen and the dissolution of transition metals. To address these issues, in this study, a Cerium oxide nano-coating layer is applied to the LRM particles using a facile wet-chemical method. Characterization through transmission electron microscopy confirms the presence of a coating layer with approximately 1.9 nm thick on the surface of the LRM particles. The optimized cathode achieves a high initial discharge capacity of 226.17 mAh/g and maintains 75.0 % of its initial capacity after 500 cycles at a high rate of 1 C. The improved electrochemical performance can be attributed to the dual function of Cerium oxide: (1) It serves as a physical barrier that isolates the LRM from the electrolyte, inhibiting interfacial side reactions; (2) it acts as an oxygen buffer layer, stabilizing lattice oxygen through the oxygen vacancies formed by the Ce 3+ /Ce 4+ redox couple. This research presents an effective surface engineering strategy to enhance the stability of anionic redox chemistry in LRM, paving the way for advanced high-energy lithium-ion batteries. Download: Download high-res image (360KB) Download: Download full-size image