Lead-free ceramics have received considerable research interest because of their environmentally friendly characteristics and superb performance in energy storage applications, which are critical for pulsed power electronic systems. In this work, we sintered a series of (0.90 − x)BiFeO3–xBaTiO3–0.10CaHfO3 lead-free ceramics and comprehensively probed the crystallographic structure, grain morphology, electrical properties, etc., to assess their capability for use in energy storage applications. The 0.50BiFeO3–0.40BaTiO3–0.10CaHfO3 ceramic achieved an ultrahigh recoverable energy storage density of 4.70 J cm−3 and an outstanding energy conversion efficiency of 79% and can be considered an excellent material candidate for use in high-power energy storage devices.
Passive electronic components made from dielectric ceramics can hardly operate at extremely high temperatures, which is attributed to the sharply increasing dielectric loss and leakage conductance. In this work, the widely applicated CaTiO 3 ceramics are used as the matrix, and the high-temperature electrical properties are modified by doping Sm 3+ and Al 3+ . The Sm-doping in CaTiO 3 ceramics can significantly suppress the dielectric relaxation at low frequencies and reduce the high-temperature leakage conductance. Continued doping of Al in Ca 0.6 Sm 0.27 TiO 3 ceramics can further reduce the high-temperature dielectric loss and conductivity. These changes are associated with tighter crystal structures and fewer defects in the ceramics. With Sm and Al doping, the high-temperature dc conductivity of the ceramics is reduced by about 4 orders of magnitude, and a dielectric loss of less than 0.02 and a low temperature cofficient of capacitance (TCC) of − 25 ppm/℃ are obtained over a wide temperature range of room temperature to 530 ℃. Outstanding temperature stabilities are exhibited over a temperature range of 25 ∼ 200 ℃ in energy storage performance and charge-discharge property. Extremely fast discharge speed ( t 0.9 = 16 ns) makes it suitable for pulsed power electronic systems. Such linear dielectric materials are expected to be used in harsh environment of high temperatures.
危险品化学品经营许可证（带存储）