Mechanochemical Transformation From Zigzag-Type Layered/Phenakite to Disordered Rocksalt in Mn-Rich Cathodes for...

Understanding how cation disorder develops in Mn-rich disordered rocksalt (DRX) systems-particularly under mechanochemical activation-has been hindered by limited insight into the underlying transformation pathways. Here, we uncover a distinct transformation route in Li_1.2Mn_(2+x)/3Mo_(0.4-x)/3O_2-xF_x (LMMOFx), in which Mo and F co-doping drives the material toward a zigzag-type layered/phenakite-mixed structure. This layered/phenakite-mixed phase undergoes pronounced local structural reconstruction, which promotes DRX formation and induces a transition from a two-phase Mn and O redox mechanism to a stable single-phase process, delivering a high reversible capacity of 297.9 mAh g^-1. Systematic structural and electrochemical comparisons across the LMMOF series further reveal how progressive disorder and phase mixing reshape Li-ion transport pathways. Together, these results establish a mechanistic framework for leveraging dopant- and structure-controlled precursor chemistry to direct mechanochemical DRX formation, and they offer a design principle for earth-abundant, Mn-rich DRX cathodes with tunable disorder.