The development of X8R BaTiO₃-based dielectric materials is of great significance for the high-temperature application of MLCCs. Herein, a series of BaTiO₃-based dielectric ceramics were prepared by the conventional solid-state method, and the effects of Bi₄Ti₃O₁₂ and Mn₃O₄ on the properties of BaTiO₃-based dielectric ceramics were studied. The SEM images show that the addition of Bi₄Ti₃O₁₂ with a low melting point can densify the ceramics at a lower sintering temperature (1,150 ℃). TEM images and EDS results indicate that the samples have a “core-shell” structure, which can be optimized by Bi₄Ti₃O₁₂, resulting in phase transition dispersion and thus improving the temperature stability of the material. The addition of Mn can reduce the dielectric loss of ceramics at high temperatures. As a result, the optimal composition exhibits a high permittivity of 2,090, a low dielectric loss of 1.1%, and high temperature stability satisfying the X8R specification.

Ceramics are considered intrinsically brittle at macro scale due to the lack of slip mechanism and pre-existing defects, which greatly limits their potential applications in emerging fields including wearable electronic devices and flexible display. In this contribution, we developed BiFeO₃/SiO₂ dual-networks with exceptional flexibility through a coupled electronetting/electrospun method. The hybrid nanostructured networks endow the material with high tensile strength (2.7 MPa), excellent flexibility (80% recoverable deformation), and robust fatigue resistance performance (maintain flexibility after a 1000-cyclic compress test). After in-situ compounded with dielectric polymer via a layer-by-layer solution casting method, the resultant three-dimensional (3D) composite film exhibits a twice higher dielectric constant (ε_r) than polyether imide (PEI) film. More importantly, the breakdown strength of the 3D composite film is almost the same as that of the PEI film, resulting in an enhanced energy density of ~6.0 J/cm³ and a high efficiency of 80% at 4.58 MV/cm. The unique structure, combined with the excellent balance between mechanical and dielectric properties in flexible structures, is of critical significance to the design of flexible functional ceramics and broadening their applications in wearable electric devices.