Dynamic Reconstruction of the Surface Lattice to Stabilize Lithium Nickel Oxide Cathodes via Molybdenum Modification

Cobalt-free, nickel-rich oxides are promising cathode materials with high energy density but suffer from poor reversibility due to unstable surface and anisotropic phase transitions. We report the performance improvement of LiNiO 2 by Mo doping within the bulk and epitaxial growth of Li 4 MoO 5 on the surface. Mo-modification exerts multiple effects, including construction of a three-dimensional Li + diffusion channel, reduction in surface reaction activity, and alleviation of structural strain, which collectively enhance Coulombic efficiency and stabilize lattice oxygen up to a charging voltage of 4.8 V. The interdiffusion of Li, Ni, and Mo between the surface Li 4 MoO 5 and bulk LiNiO 2 facilitates in situ reconstruction of the surface lattice to form a Mo-rich Li + /Ni 2+ superlattice structure that anchors surface oxygen and promotes liberation of additional Li + from Li 4 MoO 5 for charge compensation. This study reveals the dynamic structural changes of Mo-modified LiNiO 2 and proposes strategies to address lithium-loss and structure-instability issues in cycling nickel-rich cathode materials.