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Dielectric capacitors with ultrahigh power density have emerged as promising candidates for essential energy storage components in electronic and electrical systems. They enable enhanced integration, miniaturization, and lightweight design. However, the development of dielectric materials for cutting-edge energy storage applications has been significantly limited by their low recoverable energy storage density (Wrec) and energy efficiency (η), especially at moderate electric fields. In this study, we fabricated 0.85K0.5Na0.5NbO3-0.15Sr0.7Nd0.2ZrO3 ceramics with an outstanding energy storage performance (Wrec ~ 7 J cm−3, η ~ 92% at 500 kV cm−1; Wrec ~ 14 J cm−3, η ~ 89% at 760 kV cm−1). The exceptional energy storage performance can be primarily attributed to the heterogeneous structure, where orthorhombic and tetragonal polar nanoregions are embedded in a cubic matrix. This work provides a good paradigm for designing dielectric materials with ultrahigh energy storage density and excellent energy efficiency at a moderate applied electric field, aligning with the stringent demands for advanced energy storage applications. The authors propose a design strategy for lead-free relaxors, characterized by a heterogeneous structure that is constructed through a multi-scale process, resulting in high energy storage performance. [ABSTRACT FROM AUTHOR]

Multilayer ceramic capacitor as a vital core-component for various applications is always in the spotlight. Next-generation electrical and electronic systems elaborate further requirements of multilayer ceramic capacitors in terms of higher energy storage capabilities, better stabilities, environmental-friendly lead-free, etc., where these major obstacles may restrict each other. An effective strategy for energy storage performance global optimization is put up here by constructing local polymorphic polarization configuration integrated with prototype device manufacturing. A large energy density of 20.0 J·cm−3 along with a high efficiency of 86.5%, and remarkable high-temperature stability, are achieved in lead-free multilayer ceramic capacitors. The strategy provides a feasible routine from nano, micro to macro regions in manipulating local polarizations, domain-switching barriers and breakdown strength, illustrating its great potential to be generally applicable in the design of high-performance energy storage multilayer ceramic capacitors. The authors report the enhanced energy storage performances of the target Bi0.5Na0.5TiO3-based multilayer ceramic capacitors achieved via the design of local polymorphic polarization configuration and the fabrication of prototype devices. [ABSTRACT FROM AUTHOR]

Ferroelectricity in crystalline hafnium oxide has attracted considerable attention because of its potential application for memory devices. A recent breakthrough involves electric-field-induced crystallization, allowing HfO2-based materials to avoid high-temperature crystallization, which is unexpected in the back-end-of-line process. However, due to the lack of clarity in understanding the mechanisms during the crystallization process, we aim to employ theoretical methods for simulation, to guide experimental endeavors. In this work, we extended our phase-field model by coupling the crystallization model and time-dependent Ginzburg-Landau equation to analyze the crystalline properties and the polarization evolution of Hf0.5Zr0.5O2 thin film under applying an electric field periodic pulse. Through this approach, we found a wake-up effect during the process of crystallization and a transformation from orthorhombic nano-domains to the stripe domain. Furthermore, we have proposed an innovative artificial neural synapse concept based on the continuous polarization variation under applied electric field pulses. Our research lays the theoretical groundwork for the advancement of electric-field-induced crystallization in the hafnium oxide system. [ABSTRACT FROM AUTHOR]

At present, the rapid development of electronic devices such as batteries, sensors, capacitors and so on is creating a huge demand for lightweight materials with a designed structure and function. Ti3C2Tx MXene, a lightweight two-dimensional (2D) nanomaterial with excellent electronic properties, has been favored in this field. In this work, Ti3C2Tx MXene was annealed under an inert gas (N2, Ar and CO2) atmosphere to design the crystal structure and interface of the nanosheets, and then the modified nanosheets with specific changes in dielectric properties were obtained. Among them, the key temperature points (100 °C, 300 °C, 500 °C and 800 °C) in the thermogravimetric (TG) test under an air atmosphere were used as the annealing temperature. When annealing under an air atmosphere, with the increase in temperature, the Ti layer gradually oxidized and evaporated, and the original two-dimensional structure was partly destroyed with some of the C atoms reacting with O2 to form CO2. In the inert gas atmosphere, however, the 2D structure is preserved, except that the surface end groups and layer spacing are changed. In addition, some N element doping was introduced into the nanosheets after N2 atmosphere treatment, which changed the original lattice structure. After the Ar atmosphere treatment, some Ti atoms on the surface were oxidized in situ to form TiO2 grains with different crystal forms, which increased the interfacial area. The C-TiO2 structure of the nanosheets was more complete after treatment with the CO2 atmosphere. All the nanosheets after heat treatment with an inert gas atmosphere retained the characteristic morphology of 2D materials, and different changes in the micro-structure caused changes in dielectric properties, thereby meeting the needs of 2D nanomaterials Ti3C2Tx MXene in different scenarios. [ABSTRACT FROM AUTHOR]