A Unique Wide‐Spacing Fence‐Type Superstructure for Robust High‐Voltage O3‐Type Sodium Layered Cathode

Enhancing the energy density of layered oxide cathode materials is of great significance for realizing high-performance sodium-ion batteries and promoting their commercial application. Lattice oxygen redox at high voltage usually enables a high capacity and energy density. But the structural degradation, severe voltage decay, and the resultant poor cycling performance caused by irreversible oxygen release seriously restrict the practical application. Herein we introduce a novel fence-type superstructure (2a×3a type supercell) into O3-type layered cathode material Na