Boosting Li+ Diffusion in Lithium-Rich Oxides through Intrinsic Structural Design: Insights and Design Principles

Abstract Lithium-rich oxide cathodes present high specific capacities (> 250 mAh g −1 ) and wide operating voltage windows (2.0–4.8 V), making them promising candidates for next-generation high-energy batteries. Their practical deployment, however, is limited by sluggish ion transport kinetics that arise from inherent structural constraints, including confined two-dimensional diffusion channels, transition metal migration, and local lattice distortions. These structural perturbations narrow Li + pathways, intensify cation mixing, and generate localized strain fields, collectively increasing the Li + migration energy barrier. To facilitate the rational design of fast-kinetic lithium-rich oxides through intrinsic structural optimization, a comprehensive elucidation of the structure–diffusion interplay is presented, with emphasis on the roles of lattice distortion and oxygen redox chemistry in modulating Li + pathways and associated energy barriers. Structural design strategies that aim to improve ionic diffusivity are systematically evaluated, including interface engineering, morphology-directed design, and the modulation of redox chemistry. Advanced operando characterization techniques that capture dynamic structural and chemical evolution are also described as essential tools for guiding precise structure–performance analysis. The mechanistic insights and integrated analytical approaches summarized in this review establish a robust conceptual foundation for engineering lithium-rich oxides with enhanced ion transport kinetics, thereby supporting the advancement of next-generation high-power battery technologies.