Orthogonal orientation incorporated gradient-sandwich structure for enhanced energy storage performance of all-inorganic nanocomposites

Dielectric energy storage capacitors, widely used in advanced domains of electronics and power, play a crucial role in electronic systems. However, current challenges stem from the coupled limitations of polarization and breakdown field strength in dielectric capacitors, which present significant obstacles to achieving a breakthrough in energy storage performance. Here, we propose an orthogonal design for all-inorganic nanocomposite using innovative composite molding techniques. The increased path tortuosity is tailored during the electrical treeing process through the orthogonal distribution of ferroelectric nanofillers, ensuring the preservation of high breakdown strength and polarization. Meanwhile, a gradient-sandwich multilayer configuration is developed to leverage the interfacial polarization effect and interface barrier effect between adjacent layers. Hence, integrating a gradient electric field distribution enhances both the polarization and breakdown strength of the nanocomposites, ultimately resulting in a significant improvement in energy storage performance. The ultrahigh energy density of 24.5 J cm⁻³ at a low electric field of 1700 kV cm⁻¹ is obtained in orthogonal orientation gradient-sandwich structure ≈1.8 times that of the parallel filler orientations nanocomposites. Incorporating the orthogonal orientation and gradient-sandwich structure strategy significantly enhances energy output, making it suitable for a wide range of electronic devices.