Spatially Selective Substitution Enabled [001]‐Oriented Li _1.2 Ni _0.2 Mn _0.6 O ₂ Cathodes With C

Abstract

Lithium‐rich manganese‐based cathodes offer high energy density for next‐generation lithium‐ion batteries, yet practical deployment requires simultaneous enhancement of rate capability and oxygen stability. Here, a selective Mo 6+ and Sr 2+ doping strategy is proposed to regulate facet energetics and particle growth. Density functional theory calculations suggest that selective modification of facet surface energies promotes preferential growth along the [001] direction, leading to micrometer‐scale quasi‐single‐crystal Li 1.2 Ni 0.2 Mn 0.6 O 2 particles with preferentially exposed Li + ‐favorable diffusion facets. The proposed growth behavior is consistent with TEM observations. EPMA and depth‐profiled XPS reveal a spatially differentiated dopant distribution, with Sr enriched near the particle surface and Mo distributed more uniformly within the particle, consistent with the observed oriented morphology. The engineered particle structure reduces c ‐axis lattice strain by 47.2% during charging, as revealed by ex situ XRD, and suppresses oxygen release, consistent with DFT analysis of oxygen‐ion migration behavior and DEMS measurements (from 1.13 to 0.61 µmol g −1 ). In addition, the modified cathode exhibits enhanced Li + transport kinetics and improved interfacial stability. Consequently, the 5C discharge capacity increases from 133.6 to 163.1 mAh g −1 , accompanied by improved cycling stability. This work provides an effective strategy for simultaneously improving rate capability and oxygen stability in Li‐rich cathodes.