Remarkable energy-storage performances and excellent stability in CaTiO3-doped BiFeO3-BaTiO3 relaxor ferroelectric ceramics

The actual pulse capacitor application of BiFeO3-based relaxor ferroelectric ceramics has been greatly hindered by low dielectric breakdown strength and poor thermal stability. In this work, these issues are solved by manufacturing nanodomain-engineered and grain-engineered BiFeO3-BaTiO3-CaTiO3 relaxor ferroelectric ceramics. The introduction of CaTiO3 induces nanoscale domains in the ferroelectric BiFeO3-BaTiO3 matrix, bringing about temperature-insensitive dielectric response and almost hysteresis-free polarization field response. Furthermore, largely enhanced dielectric breakdown strengths are also achieved, which is mainly attributed to the refinement of the grain size and the depression of the oxygen vacancy concentration. Consequently, remarkable energy-storage performances with high recoverable energy density (Wrec ∼ 5.03 J/cm3), high efficiency (η ∼ 89.7%), and outstanding thermal stability (Wrec variation < 4% from 30 to 150 ℃) are obtained. Moreover, ultrafast release time (t0.9 ∼ 65 ns) and high power density (∼75.14 MW/cm3) are also achieved, proving the BiFeO3-BaTiO3-CaTiO3 ceramics' enormous potential for underlying advanced pulse capacitor applications.