Rate Capability of Lithium‐Rich Manganese‐Based Oxide Cathodes: Charge–Discharge Kinetics, Multiscale Bottlenecks, and Dynamic Rate‐Determining Steps

Lithium‐rich manganese‐based oxide (LRMO) cathode materials deliver a reversible specific capacity exceeding 250 mAh g −1 through synergistic anionic and cationic redox, promising for next‐generation high‐energy‐density batteries, yet their poor rate capability remains a critical barrier to practical deployment, particularly for fast‐charging applications. This review deconstructs rate‐limiting mechanisms at three levels, namely direct charge‐transport impediments, kinetic sluggishness of anionic redox, and degradation cascade of phase transformations, voltage decay, and microcracking that exacerbates kinetics. A central insight is that the rate‐determining step (RDS) shifts from electron‐transfer to ion‐diffusion dominance, governed by the exchange current density ( j 0 ) and the limiting current density ( j d ). Modification strategies are classified into two threads, kinetic enhancement by shortening diffusion paths and lowering migration barriers, and structural stabilization by reinforcing bonds and suppressing oxygen release. Importantly, the often‐overlooked charging kinetics are critically assessed, as the asymmetric nature of anionic redox imposes a more severe bottleneck for fast charging than for high‐rate discharging. Methodological limitations in cross‐study C‐rate comparisons, arising from variations in electrode loading and testing protocols, are also examined to enable more rigorous evaluation of reported performance. This review ultimately provides a theoretical foundation for rational design of high‐rate LRMO cathodes toward practical energy storage applications.