Researchers engineered lead-free BCZT/STO superlattice capacitors that achieved a recoverable energy storage density of 12.6 J/cm³ with near-99 % efficiency at 920 kV/cm, while maintaining stable performance through 2 × 108 charge–discharge cycles. Atomic-scale measurements indicate that the superlattice changes the size and spatial organization of polar nanoregions, while a strain-gradient-related internal field also contributes to the observed energy-storage behavior.
