Recent Advances in Oxygen Redox Activity of Lithium-Rich Manganese-Based Layered Oxides Cathode Materials: Mechanism, Challenges and Strategies

Lithium-rich manganese-based layered oxides (LRMOs) have been regarded as a promising category of cathode materials due to their high specific capacity on basis of joint anionic(oxygen) /cationic redox chemistry at a high voltage, thus high energy density. The anionic redox play the key and restive roles in LRMOs, contributing the extra capacity, meanwhile being associated with several unfavorable structural and electrochemical issues. This work systematically enumerates the oxygen redox mechanisms, and challenges associated with oxygen-anion redox in LRMOs, including irreversible transition metal migration, phase transition, and the capacity/voltage decay, etc. The recent progress made in modification of LRMOs with particular emphasis to promoting the reversible oxygen redox reaction and inhibiting the irreversible oxygen release are summarized, followed by an outlook on the future rational design and development of LRMOs. This comprehensive review and perspective are expected to provide insights for the greater utilization of oxygen redox in LRMOs and other related materials. This work systematically enumerates the oxygen redox mechanisms, and related challenges in Lithium-rich manganese-based layered oxides. The recent modification strategies with particular emphasis to promoting the reversible oxygen redox reaction and inhibiting the irreversible oxygen release are summarized, followed by an outlook. This comprehensive review and perspective are expected to provide insights for the greater utilization of oxygen redox in LRMOs and other counterparts, such as sodium-based ones, sulfides, etc. image