With the wide application of energy storage equipment in modern electronic and electrical systems, developing polymer-based dielectric capacitors with high-power density and rapid charge and discharge capabilities has become important. However, there are significant challenges in synergistic optimization of conventional polymer-based composites, specifically in terms of their breakdown and dielectric properties. As the basis of dielectrics, all-organic polymers have become a research hotspot in recent years, showing broad development prospects in the fields of dielectric and energy storage. This paper reviews the research progress of all-organic polymer dielectrics from the perspective of material preparation methods, with emphasis on strategies that enhance both dielectric and energy storage performance. By dividing all-organic polymer dielectrics into linear polymer dielectrics and nonlinear polymer dielectrics, the paper describes the effects of three structures (blending, filling, and multilayer) on the dielectric and energy storage properties of all-organic polymer dielectrics. Based on the above research progress, the energy storage applications of all-organic dielectrics are summarized and their prospects discussed.

In the present study, we have performed molecular dynamics simulations to describe the microscopic behaviors of the anionic, nonionic, zwitterion, and gemini surfactants at oil/water interface. The abilities of reducing the interfacial tension and forming the stable interfacial film of the four surfactants have been investigated through evaluating interfacial thickness, interface formation energy and radial distribution function. The results show that the four kinds of surfactants can form in stable oil/water interface of monolayer, and the gemini surfactant can form the more stable monolayer. The results of the above three parameters demonstrate that the gemini surfactant has the best simulation effect in the four surfactants. From the calculated interfacial tension values, the gemini surfactant possess the more powerful ability of reducing the interfacial tension than others, so it is more suitable to be used as the surfactant for flooding. In addition, the effects of different electric field intensities on surfactants were calculated, through the radial distribution function of the hydrophilic group in the surfactant and the oxygen atom in the water. We have found that the adding of the periodic electric field can significantly affect the diffusion behavior of the molecules, and nonionic surfactant has stronger demulsification capability than others. GRAPHICAL ABSTRACT

Polymeric materials have many applications in multiple industries. In this paper, silicon nitride nanoparticles (Si₃N₄) were incorporated into a polyimide (PI) matrix to obtain composite films via the in situ polymerization method. The Si₃N₄ nanoparticles were consistently scattered in the composites, and the thickness of PI/Si₃N₄ films was around 50 µm. The effects of nanoparticle content on the dielectric constant, loss tangent and breakdown strength were simultaneously studied. A 3 wt.% doped PI/Si₃N₄ film revealled excellent dielectric properties, a dielectric constant (ε) of 3.62, a dielectric loss tangent (tanδ) of 0.038, and a breakdown strength of 237.42 MV/m. The addition of Si₃N₄ formed an interface layer inside PI, resulting in a large amount of space charge polarization in the electric field. The space charge of materials from the microscopic point of view was analyzed. The results show that there are trapenergy levels in the composites, which can be used as a composite carrier center and transport channel, effectively improving the performance of a small amount of nanoparticles film.

The thermodynamic values of the four surfactants, anionic surfactants, nonionic surfactants, zwitterion surfactants and gemini surfactants, were calculated by molecular dynamics simulation.

Improving the energy storage density of dielectrics without sacrificing charge-discharge energy storage efficiency and reliability is crucial to the performance improvement of modern electrical and electronic systems, but traditional methods of doping high-dielectric ceramics cannot achieve high energy storage densities without sacrificing reliability and storage efficiency. Here, an all-organic energy storage dielectric composed of ferroelectric and linear polymer with a sandwich structure is proposed and successfully prepared by the electrostatic spinning method. Additionally, the effect of the ferroelectric/linear volume ratio on the dielectric properties, breakdown, and energy storage is systematically studied. The results show that the structure has good energy storage characteristics with a high energy storage density (9.7 J/cm³) and a high energy storage efficiency (78%). In addition, the energy storage density of the composite dielectric under high energy storage efficiency (90%) is effectively improved (25%). This result provides theoretical analysis and experience for the preparation of multilayer energy storage dielectrics which will promote the development and application of energy storage dielectrics.