Enhanced Dielectric and Energy Storage Properties in Fe‐Doped BCZT Ferroelectric Ceramics

x mol% Fe‐doped Ba(Zr 0.2 Ti 0.8 )O 3 ‐50 mol%(Ba 0.7 Ca 0.3 )TiO 3 (abbreviated as x Fe:BCZT) ferroelectric ceramics with x = 0, 0.075, 0.375, 0.75, 1.5, and 3 are fabricated via conventional solid‐state reaction methods. Fe incorporates into the lattice, and all the x Fe:BCZT ceramics show pure perovskite structure except 3Fe:BCZT ceramics in which tiny amount of iron oxide is detected via X‐ray diffraction (XRD). The average grain sizes are significantly reduced from ≈20 to ≈2 μm with increasing Fe‐doping content. The Curie temperature of x Fe:BCZT ceramics decreases with increasing Fe‐doping concentration and the room temperature dielectric constant significantly increased. Polarization hysteresis loops become slim after Fe‐doping. The recoverable energy storage density W rec of x Fe:BCZT ceramics is slightly enhanced to 0.240 J cm −3 with an energy storage efficiency η % = 70.1% at x = 0.075 under E ‐field of 50 kV cm −1 . The η % can be enhanced to as high as 93.8% at x = 3 with W rec = 0.153 J cm −3 due to a slim P – E loops via Fe‐doping. The results indicate a potential method to fabricate high efficiency energy storage materials via Fe‐doping.