Constructing superrelaxor critical state towards giant energy storage in lead-free dielectric ceramics

Lead-free relaxor ferroelectric ceramics are promising candidates for advanced pulsed power systems owing to their combination of exceptional power density and ultrafast charge-discharge capabilities. However, the simultaneous realization of ultrahigh recoverable energy density (Wrec) and high efficiency (η) remains a persistent challenge, as strategies to enhance polarization typically increase hysteresis losses. To address this issue, we propose a strategy actively constructing a superrelaxor critical state—a crossover from dynamic to static/frozen relaxor states—through targeted compositional tuning and polarization configuration control. Guided by phase-field simulations and first-principles calculations,…