Yi-Chen Wu

Advisor: Professor Meilin Liu

will defend a master thesis entitled,

Mechanochemical Transformation from Zigzag-Type Layered/Phenakite to Disordered Rocksalt in Mn-Rich Cathodes for Li-Ion Batteries

On

Friday, April 03, 2026

10:00 am - 12:00 pm

J. Erskine Love Building

Classroom 183

or virtually via Zoom:

Zoom Link

Committee:

Professor Meilin Liu - School of Materials Science and Engineering (advisor)

Professor Hailong Chen - School of Materials Science and Engineering

Doctor Yong Ding - School of Materials Science and Engineering

Abstract:

    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 Li1.2Mn(2+x)/3Mo(0.4-x)/3O2-xFx (LMMOFx), in which Mo and F co-doping drives the material toward a zigzag-type layered/phenakite mixed structure. This co-doped mixed phase undergoes pronounced local structural reconstruction, which promotes DRX formation and induces a transition from a two-phase Mn 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.