Aliovalent A-site engineering enables superior energy storage density in AgNbO₃ lead-free antiferroelectric ceramics.

High energy density was achieved by designing a AgNbO ₃ based lead-free system.

Dielectric composites boost the family of energy storage and conversion materials as they can take full advantage of both the matrix and filler. This review aims at summarizing the recent progress in developing high‐performance polymer‐ and ceramic‐based dielectric composites, and emphases are placed on capacitive energy storage and harvesting, solid‐state cooling, temperature stability, electromechanical energy interconversion, and high‐power applications. Emerging fabrication techniques of dielectric composites such as 3D printing, electrospinning, and cold sintering are addressed, following by highlighted challenges and future research opportunities. The advantages and limitations of the typical theoretical calculation methods, such as finite‐element, phase‐field model, and machine learning methods, for designing high‐performance dielectric composites are discussed. This review is concluded by providing a brief perspective on the future development of composite dielectrics toward energy and electronic devices.

Imprinting oxides: Dislocations can be problematic for the properties of functional oxides and are often avoided as a result. Höfling et al. found that introducing a network of dislocations to barium titanate actually enhanced the dielectric and piezoelectric properties. The authors introduced the dislocation network with uniaxial compression, which forced the material to have a domain structure that enhanced the piezoelectric coefficient by a factor of 19. This strategy should be a useful tool for optimizing properties of other functional oxides. Science , abe3810, this issue p. 961

An ultrahigh energy storage density up to 4.87 J cm ⁻³ was achieved in Sm/Ta co-doped AgNbO ₃ ceramics, by decreasing the cation displacement and [Nb/TaO ₆ ] octahedral tilting angle.