M = Co, Ni) can deliver a theoretical specific capacity exceeding 300 mAh g −1 by unlocking the anionic redox chemistry. [2] However, LRMOs are plagued by issues of low Coulombic efficiency, capacity/voltage decay and voltage hysteresis mainly due to irreversible oxygen loss and transition metal (TM) migration. [3] Oxygen loss is proposed to lower the migration barrier of transition metals, induce the formation of cracks, accelerate electrolyte decomposition, and further impose thermal runway risk. [4] Many approaches, such as composition tailoring, [5] element doping, [6] gradient concentration design [7] and surface coating, [8] have been established to stabilize LRMOs. Among them, surface coating is most straightforward to mitigate oxygen loss on charging LRMOs.For practical electrode fabrication, cathode materials are usually prepared in microspheres composed of nanosized primary particles to achieve high tap density and facilitate slurry preparation and casting on current collector. Most reported coating techniques, for example, ball milling, atomic layer deposition and wet chemistry method involving coprecipitation and calcination, often build a protective layer on the secondary particles due to weak interaction between inner primary particles and coating material. Few researches have realized effective coating on primary particles of cathode materials. [9] For example, atomic layer deposition and high temperature annealing was employed to melt coated Li 3 PO 4 layer into grain boundaries of LiNi 0.76 Mn 0.14 Co 0.10 O 2 . [9b] Besides, a conformal poly(3,4-ethylenedioxythiophene) layer was generated on both secondary and primary particles of LiNi 0.85 Co 0.10 Mn 0.05 O 2 and Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 by oxidative chemical vapor deposition. [9c] Recently, a reactive boride infusion strategy was adopted to coat Co x B on primary particles of LiNi 0.8 Co 0.1 Mn 0.1 O 2 at room temperature. [9d] However, these primary particle coating strategies are often plagued by high cost and/or complicated procedures. It is desirable to develop facile, scalable routes for surface modification of primary particles to improve the performance of LRMO cathode materials.In this study, we proposed a simple yet efficient strategy for homogenously coating Li 2 TiO 3 (LTO) on the primary particles of Li 1.08 Mn 0.54 Co 0.13 Ni 0.13 O 2 (LRMO). As a lithium-ion conducting material, LTO not only exhibits chemical and Li-rich Mn-based oxides (LRMOs) are promising cathode materials for next-generation lithium-ion batteries (LIBs) with high specific energy (≈900 Wh kg −1 ) because of anionic redox contribution. However, LRMOs suffer from issues such as irreversible release of lattice oxygen, transition metal (TM) dissolution, and parasitic cathode-electrolyte reactions. Herein, a facile, scalable route to build homogenous and ultrathin Li 2 TiO 3 (LTO) coating layer on the primary particles of LRMO through molten salt (LiCl) assisted solid-liquid reaction between TiO 2 and Li 1.08 Mn 0.54 Co 0.13 Ni 0.13 O 2 is repo...