Constructing amorphous lattice buffering regions enables stable P2-type layered oxide cathodes for sodium-ion batteries

Abstract

Structural instability of P2-type layered oxide cathodes severely limits their cycling durability in sodium-ion batteries. Here, it is demonstrated that effective strain buffering during Na⁺ cycling can be achieved by incorporating localized amorphous buffer regions. The resulting amorphous–crystalline architecture accommodates volume variation, accelerates Na⁺ diffusion, and preserves small particle size, thereby stabilizing the layered framework and suppressing phase transitions. This design achieves significantly enhanced cycling stability, providing a promising strategy for robust layered cathodes.