<p>Ni-rich layered oxide cathodes derived from LiNiO₂, including Ni-rich NMC and NCA, enable high specific energy but remain constrained by coupled interfacial and lattice instabilities that intensify at elevated upper-cutoff voltages. This review examines the durability limitations of Ni-rich layered oxide cathodes as an interface-dominated issue governed by CEI evolution, HF-driven interfacial chemistry, oxygen-loss-coupled surface reconstruction, and the resulting impedance growth during high-voltage operation. We summarize ceramic interphases and Li⁺-permissive interlayers that regulate contact chemistry, suppress parasitic reactions, and preserve ionic percolation while maintaining electronic insulation. We then examine lattice substitution across transition-metal, Li, and O/anion sites, highlighting how site selectivity and dopant chemistry suppress cation disorder, stabilize the oxygen framework, and sustain Li⁺ transport at high states of charge. Finally, we discuss bulk–surface integration strategies and implications for solid-state battery interfaces, where solid–solid contact and chemo-mechanical compatibility can dominate polarization growth. By consolidating recent studies, we establish a unified design framework linking interfacial chemistry, lattice stability, and transport kinetics, thereby connecting materials chemistry and processing to practical stability targets for next-generation Ni-rich cathodes.</p> Graphical abstract <p></p>