Superior Energy Storage Performance in a Self‐Organized Trirelaxor‐Antiferroelectric Nanocomposite Over a Wide Temperature Range

), outperforming existing Pb-free dielectrics. High-resolution transmission electron microscopy and synchrotron x-ray diffractometry reveal that the coexisting nanometric antiferroelectric particles and the trirelaxor nanodomains sustain over a wide temperature range. Piezoresponse force microscopy and phase-field simulation show that hysteresis-free switching of trirelaxor nanodomains enables enhanced polarization and low hysteretic loss. Resistivity shows a 2-3 order of magnitude increases accompanying significant increase in breakdown strength up to high temperatures, attributable to deep charge trapping effect at high-density TRE/AFE interfaces as evidenced by thermally stimulated depolarization current. These favorable effects in the nano-composite are responsible for its high energy storage performance up to high temperatures.