Advanced dielectric polymers for energy storage

The miniaturization of electronic devices and the structural optimization of power systems put forward a strict size requirement for passive components such as capacitors. The thickness reduction of dielectric polymer films becomes a necessary and urgent measure for future technology development. This advance leads to a higher capacitance density, less raw resource consumption, and lightweight modules and systems. However, the thickness change inevitably challenges the dielectric properties, the surface condition, and their relationship with the fabrication method of the dielectric films. This review primarily discusses: (1) the influence of polymer film thickness on the dielectric properties, (2) film quality issues in thinner polymer films with different filler contents, (3) high-temperature dielectric polymer engineering, and (4) the major processing methods in decreasing polymer film thickness. In addition, the polymer films also require scalability, processibility, and industrial feasibility in film and component manufacturing. The perspective of future investigations and concerns of dielectric polymer films are shared. It is interesting to see the favorable effect of multilayer polymer films on enhancing the dielectric strength.