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_vs offers a scalable design strategy for high-performance efficient electrochemical systems.