Visualizing lithium-rich manganese-based layered oxides: Advancing dynamic monitoring to decipher battery chemistry

Lithium-rich manganese oxides (LRMOs) show great promise as high capacity, cost effective cathodes for next-generation Li-ion batteries, Nevertheless, they still confront issues such as voltage decline, capacity loss, and structural instability. Recent breakthroughs in in situ / operando characterization methods have emerged as highly effective means for uncovering the dynamic changes in structure and electrochemical activity of these materials. This review delves into advanced methodologies enabling the real time observation of phase alterations, oxygen redox interactions, and the migration of transition metals (TMs) throughout the battery's charge/discharge cycles. By combining various characterization tools, researchers can reveal crucial connections between defect formation, redox mechanisms, and the stability of the battery's structure, enabling the development of novel approaches to suppress performance degradation. The study illustrates that mechanistic insights into phase transitions and failure modes, gained through advanced characterization, are instrumental in improving LRMOs. Prioritizing multiscale in situ methodologies coupled with machine learning for data interpretation will be crucial for rapidly developing viable LRMOs. These advancements in real time analysis hold promise for addressing current limitations and fast tracking the market introduction of high-energy-density materials for future energy storage.