Superionic Conduction Through Lattice Engineering of Fluorites Stabilizing Periodic Oxygen Vacancy Network

Superionic conductors with an exceptionally high ionic conductivity are placed central in the development of next‐generation energy conversion and storage technologies, yet their designing approach and materials remain a persistent challenge. Here, we report an alternative cation‐ordered Ce–Al (1:1) fluorite oxide (ACO) that stabilizes a periodic oxygen vacancy (O v ) network to build the required architecture. The resulting lattice‐engineered configuration creates a uniform and flattened potential energy landscape with significantly reduced activation energy, capable of a superionic conductivity of 0.216 S cm −1 and a fuel cell power density of 1086 mW cm −2 at 500 °C. Unlike conventional random ion hopping in doped oxides, the vacancy‐ordered framework supports coherent, phonon‐assisted and wave‐like ions motion enabling dielectric‐enhanced superionic conduction. These findings introduce a new family of superionic conductors, where lattice‐level ordering of both cations and O v s offers a scalable design strategy for high‐performance efficient electrochemical systems.