Nucleation-promoting and growth-limiting synthesis of disordered rock-salt Li-ion cathode materials

Manganese-based disordered rock-salt (Mn-DRX) oxides and oxyfluorides are promising cathode materials for high-performance, nickel- and cobalt-free Li-ion batteries. However, existing synthesis methods for these materials require post-synthesis particle pulverization to achieve acceptable particle size for cycling, which lacks control over particle microstructure and crystallinity, accelerating performance degradation and limiting secondary particle processing. In this study, we propose a universal synthesis method using Li1.2Mn0.4Ti0.4O2 as a representative Mn-DRX, which promotes nucleation while limiting particle growth and agglomeration. This method controls the particle size while preserving the crystallinity to produce highly crystalline, dispersed sub-200 nm single particles, which form homogeneous electrode films with significantly improved capacity retention (84.3% over 100 cycles at ~200 mAh/g) and discharge voltage retention (4.8 mV loss per cycle) compared to electrodes made from particles synthesized through traditional solid-state synthesis followed by pulverization (38.1% capacity retention and 7.5 mV loss per cycle). Our approach offers a new direction for Mn-DRX research and development in nickel- and cobalt-free Li-ion batteries.