<p>Ni-rich layered oxide cathodes have emerged as pivotal candidates for next-generation lithium-ion batteries (LIBs) due to their exceptional capacity and energy density. However, their intrinsic susceptibility to both dynamic structural deterioration and solid-liquid interfacial degradation during cycling results in substantial capacity fade, posing critical challenges for commercialization. To address these limitations, we propose a synergistic strategy of lattice doping and <i>in situ</i> surface coating to simultaneously enhance the structural integrity and interfacial stability of Ni-rich cathode material (LiNi_0.9Co_0.05Mn_0.05O₂). The La and Y dopants act as pillars to reinforce the layered structure of the cathode, mitigating volume changes while expanding the <i>c</i>-axis spacing to facilitate Li⁺ diffusion. Meanwhile, the La₄NiLiO₈ and LiYO₂ coatings effectively protect the cathode from H₂O/CO₂ corrosion and electrolyte attack, while their high lithium-ion conductivity promotes Li⁺ transport. Consequently, the modified cathode delivers exceptional electrochemical metrics, including a high specific capacity (207.3 mA h g⁻¹), remarkable cycling stability (97.6% retention after 100 cycles), superior rate capability (152.1 mA h g⁻¹ at 10.0 C), and enhanced thermal stability. This work establishes a paradigm for multi-dimensional stabilization of Ni-rich cathodes via synergistic bulk and interface engineering, providing fundamental insights into designing high-performance energy storage systems.</p>