Giant Energy Density via Mechanically Tailored Relaxor Ferroelectric Behavior of PZT Thick Film (Adv. Mater. 45/2023)

High Energy Density Capacitors In article number 2302554, Long‐Qing Chen, Shashank Priya, Dae‐Yong Jeong, Jungho Ryu, and co‐workers reveal a giant energy storage density of over 120 J cm−3 with an ultrahigh breakdown strength of 540 MV m−1 (equivalent to the breakdown strength of ferroelectric polymers) in a nanograin engineered PZT thick film. The nano‐grain architecture composite microstructure of crystalline and amorphous phase with the same composition, achieved through mechanical tailoring, exhibits artificial relaxor ferroelectric behavior, which dramatically expands the material design space.