Local Charge Distribution Modulation Enables Robust High-Entropy Layered Oxide Cathodes with Suppressed Lattice Strain for Sodium-Ion Batteries

O3-type layered oxides have attracted a great deal of attention as cathode materials for sodium-ion batteries (SIBs) due to their high theoretical capacity and low cost. However, the crystal structure distortion induced by undesirable phase transitions during electrochemical cycling and the inherent air/moisture instability further constrain their practical application. Herein, we innovatively proposed a local charge distribution modulation strategy to develop a high-entropy NaLi0.05Ni0.3Fe0.15Cu0.05Mn0.35Ti0.1O2 (LNFCMT) cathode material, in which high-voltage lattice distortion was suppressed and air/moisture stability was enhanced, resulting in outstanding electrochemical performance and practical usability. By atomically tailoring the local chemical and electronic environment around transition metal and oxygen ions within the lattice, the material’s bonding characteristics, redox behavior, and structural stability can be modulated. Consequently, the LNFCMT half-cell demonstrates outstanding rate performance (132.5 mAh g–1 at 1C), superior long cycle life (78.6% capacity retention at 1C), low lattice strain (lattice spacing change of 0.55%), and excellent practical prospects (73.3% capacity retention at 0.2C for full-cell system). This research offers novel insights into the phase and air/moisture stability of O3-type layered oxide cathodes for SIBs.