Gradient Polarization Coupling via Configurational Entropy Engineering for Giant Energy Storage Performance

Multilayer ceramic capacitors (MLCCs) have become the core materials in advanced electronics and power equipment thanks to the excellent functional characteristics, including energy storage, filtering, and coupling. However, the next-generation electronic devices place higher demands on the energy storage performance for MLCCs. This study demonstrates that the directional regulation of gradient polarization coupling (GPC) constitutes an effective approach to achieving a giant energy storage density. With the guidance of theoretical predictions, we propose a high configurational entropy (HCE) strategy in NaNbO₃-based (NN) multilayer ceramic capacitors to constructing the alternating multipolar nanodomains. Alternately distributed weakly polar and strongly polar domains with embedding nonpolar nanoclusters possess the effective gradient coupling of polarization. Polymorphic polarization coupling realizes the dynamic orientation of local nanoclusters to drive the orientation of the overall electric dipoles, which could reduce hysteresis loss while maintaining high polarization strength. As a consequence, the NN-20H MLCCs achieve a recoverable energy storage density of 20.4 J/cm³ and an ultrahigh breakdown strength of 1680 kV/cm, which demonstrates great advancement in reported lead-free ceramic capacitors. This work illustrates the GPC strategy to advance novel insights for next-generation MLCCs with high energy storage performance.